Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| leaf conductance in relation to rate of co(2) assimilation: i. influence of nitrogen nutrition, phosphorus nutrition, photon flux density, and ambient partial pressure of co(2) during ontogeny. | plants of zea mays were grown with different concentrations of nitrate (0.6, 4, 12, and 24 millimolar) and phosphate (0.04, 0.13, 0.53, and 1.33 millimolar) supplied to the roots, photon flux densities (0.12, 0.5, and 2 millimoles per square meter per second), and ambient partial pressures of co(2) (305 and 610 microbars). differences in mineral nutrition and irradiance led to a large variation in rate of co(2) assimilation per unit leaf area (a, 11 to 58 micromoles per square meter per second) ... | 1985 | 16664333 |
| displacement of ca by na from the plasmalemma of root cells : a primary response to salt stress? | a microfluorometric assay using chlorotetracycline (ctc) as a probe for membrane-associated ca(2+) in intact cotton (gossypium hirsutum l. cv acala sj-2) root hairs indicated displacement of ca(2+) by na(+) from membrane sites with increasing levels of nacl (0 to 250 millimolar). k(+)((86)rb) efflux increased dramatically at high salinity. an increase in external ca(2+) concentration (10 millimolar) mitigated both responses. other cations and mannitol, which did not affect ca(2+)-ctc chelation p ... | 1985 | 16664372 |
| plant morphological and biochemical responses to field water deficits: i. responses of glutathione reductase activity and paraquat sensitivity. | the effects of water deficits on plant morphology and biochemistry were analyzed in two photoperiodic strains of field-grown cotton (gossypium hirsutum l.). plants grown under dryland conditions exhibited a 40 to 85% decrease in leaf number, leaf area index, leaf size, plant height, and total weight per plant. gross photosynthesis decreased from 0.81 to 0.47 milligram co(2) fixed per meter per second and the average midday water, osmotic, and turgor potentials decreased to -2.1, -2.4, and 0.3 me ... | 1985 | 16664424 |
| simultaneous measurements of steady state chlorophyll a fluorescence and co(2) assimilation in leaves: the relationship between fluorescence and photosynthesis in c(3) and c(4) plants. | rates of co(2) assimilation and steady state chlorophyll a fluorescence were measured simultaneously at different intercellular partial pressures of co(2) in attached cotton (gossypium hirsutum l. cv deltapine 16) leaves at 25 degrees c. electron transport activity for co(2) assimilation plus photorespiration was calculated for these experiments. under light saturating (1750 microeinsteins per square meter per second) and light limiting (700 microeinsteins per square meter per second) conditions ... | 1986 | 16664735 |
| the physiological significance of phenylacetic acid in abscising cotton cotyledons. | the physiological role of phenylacetic acid (paa) as an endogenous regulator of cotyledon abscission was examined using cotton (gossypium hirsutum l. cv lg 102) seedlings. application of 100 micromolar or more paa to leafless cotyledon abscission-zone explants resulted in the retardation of petiole abscission and a decrease in the rise of ethylene evolution that normally accompanies aging of these explants in vitro. the partial inhibition of ethylene evolution in these explants by paa was indire ... | 1986 | 16664834 |
| diurnal fluctuations in cotton leaf carbon export, carbohydrate content, and sucrose synthesizing enzymes. | in fully expanded leaves of greenhouse-grown cotton (gossypium hirsutum l., cv coker 100) plants, carbon export, starch accumulation rate, and carbon exchange rate exhibited different behavior during the light period. starch accumulation rates were relatively constant during the light period, whereas carbon export rate was greater in the afternoon than in the morning even though the carbon exchange rate peaked about noon. sucrose levels increased throughout the light period and dropped sharply w ... | 1986 | 16664860 |
| a rapid leaf-disc sampler for psychrometric water potential measurements. | an instrument was designed which facilitates faster and more accurate sampling of leaf discs for psychrometric water potential measurements. the instrument consists of an aluminum housing, a spring-loaded plunger, and a modified brass-plated cork borer. the leaf-disc sampler was compared with the conventional method of sampling discs for measurement of leaf water potential with thermocouple psychrometers on a range of plant material including gossypium hirsutum l., zea mays l., and begonia rex-c ... | 1986 | 16664879 |
| effects of nacl and cacl(2) on ion activities in complex nutrient solutions and root growth of cotton. | sodium displaces ca(2+) from membranes (gr cramer, a läuchli, vs polito plant physiol 1985 79: 207-211) and this can be related to the (ca(2+))/(na(+))(2) activity ratio in the external solution (gr cramer, a läuchli 1986 j exp bot 37: 321-330). supplemental ca(2+) is known to mitigate the adverse effects of salinity on plant growth. in this report we investigated the effects of nacl (0-250 millimolar) and ca(2+) (0.4 and 10 millimolar) on the ion activities in solution and on root growth of cot ... | 1986 | 16664904 |
| studies on h-translocating atpases in plants of varying resistance to salinity : ii. k strongly promotes development of membrane potential in vesicles from cotton roots. | mg(2+)-atp-dependent h(+)-translocation has been studied in membrane vesicles derived from the roots of gossypium hirsutum l. var. acala san jose 2. establishment of a positive membrane potential was followed by measuring scn(-) accumulation; establishment of deltaph across the vesicle membranes by measuring quinacrine fluorescence quenching. high specificity for atp was shown, and h(+)-translocation was oligomycin stable. the ph profile for h(+)-translocation showed an optimum at 5.5. the relat ... | 1986 | 16664943 |
| heterogeneity of catalase in maturing and germinated cotton seeds. | to investigate possible charge and size heterogeneity of catalase (ec 1.11.1.6) in cotton (gossypium hirsutum l. cv deltapine 62), extracts of cotyledons from different developmental ages were subjected to nondenaturing polyacrylamide gel electrophoresis and isoelectric focusing. special precautions (e.g. fresh homogenates, reducing media) were necessary to prevent artefacts due to enzyme modification during extraction and storage. when the gels were stained for enzyme activity, two distinct ele ... | 1986 | 16664956 |
| canopy photosynthesis and its relationship to plant productivity in near-isogenic cotton lines differing in leaf morphology. | a 2-year study was conducted to determine the relationships between plant canopy photosynthesis, canopy light interception, and plant productivity of cotton (gossypium hirsutum l.) exhibiting differing leaf morphologies. the near-isogenic lines were from a single background (md 65-11) and represented the leaf shapes normal (small leaf lobing), sub-okra (intermediate leaf lobing), okra (large leaf lobing), and super okra (severe leaf lobing). the f(1) of a cross normal x okra (intermediate leaf l ... | 1986 | 16665085 |
| the response of foliar gas exchange to exogenously applied ethylene. | the responsiveness to ethylene of net photosynthesis and stomatal conductance to water vapor in intact plants was investigated in 13 herbaceous species representing seven plant families. exposures were conducted in an open, whole-plant exposure system providing controlled levels of irradiance, air temperature, co(2), relative humidity, and ethylene concentration. net photosynthesis and stomatal conductance to water vapor in units of moles per square meter per second were measured on recently exp ... | 1986 | 16665086 |
| effects of water stress on the organic acid and carbohydrate compositions of cotton plants. | two photoperiodic cotton (gossypium hirsutum l.) strains (t185 and t466) which had been empirically selected because of poor performance and two strains (t25 and t256) selected because of enhanced performance under field water stress were evaluated for stress-induced changes in their organic acids and carbohydrates. profiles and quantitation of organic acids and carbohydrates from aqueous extractions of cotton leaf tissue were determined by high performance liquid chromatography. in all cases, t ... | 1986 | 16665100 |
| carbon accumulation during photosynthesis in leaves of nitrogen- and phosphorus-stressed cotton. | leaves of cotton (gossypium hirsutum l.) accumulate considerable dry mass per unit area during photosynthesis. the percentage of c in that accumulated dry mass was estimated as the regression coefficient (slope) of a linear regression relating c per unit area to total dry mass per unit area. plants were grown on full nutrients or on n- or p-deficient nutrient solutions. in the fully nourished controls, the mass that accumulated over a 9-hour interval beginning at dawn contained 38.6% c. n and p ... | 1986 | 16665124 |
| effects of nacl and cacl(2) on cell enlargement and cell production in cotton roots. | in many crop species, supplemental ca(2+) alleviates the inhibition of growth typical of exposure to salt stress. in hydroponically grown cotton seedlings (gossypium hirsutum l. cv acala sj-2), both length and weight of the primary root were enhanced by moderate salinities (25 to 100 millimolar nacl) in the presence of 10 millimolar ca(2+), but the roots became thinner. anatomical analysis showed that the cortical cells of these roots were longer and narrower than those of the control plants, wh ... | 1986 | 16665141 |
| cytokinin-induced ethylene biosynthesis in nonsenescing cotton leaves. | the influence of cytokinins on ethylene production was examined using cotton leaf tissues. treatment of intact cotton (gossypium hirsutum l. cv lg 102) seedlings with both natural and synthetic cytokinins resulted in an increase in ethylene production by excised leaves. the effectiveness of the cytokinins tested was as follows: thidiazuron > ba > isopentyladenine >/= zeatin > kinetin. using 100 micromolar thidiazuron (tdz), an initial increase in ethylene production was observed 7 to 8 hours pos ... | 1986 | 16665168 |
| concentrations of abscisic acid and indoleacetic acid in cotton fruits and their abscission zones in relation to fruit retention. | an experiment was conducted with field-grown cotton (gossypium hirsutum l.) to determine the effects of drought and an increase in available photosynthate on the abscisic acid (aba) and indoleacetic acid (iaa) contents of 3-day-old bolls and their abscission zones. photosynthate availability was manipulated by removing about two-thirds of the plants to permit increased irradiance, and thus photosynthesis, in the plant canopy. the demand for photosynthate was decreased by removing all bolls from ... | 1987 | 16665202 |
| influx of na, k, and ca into roots of salt-stressed cotton seedlings : effects of supplemental ca. | high na(+) concentrations may disrupt k(+) and ca(2+) transport and interfere with growth of many plant species, cotton (gossypium hirsutum l.) included. elevated ca(2+) levels often counteract these consequences of salinity. the effect of supplemental ca(2+) on influx of ca(2+), k(+), and na(+) in roots of intact, salt-stressed cotton seedlings was therefore investigated. eight-day-old seedlings were exposed to treatments ranging from 0 to 250 millimolar nacl in the presence of nutrient solutio ... | 1987 | 16665280 |
| replication of cauliflower mosaic virus dna in leaves and suspension culture protoplasts of cotton. | cauliflower mosaic virus (camv) replicated in protoplasts and in inoculated leaves of the non-host, cotton (gossypium hirsutum, l.). protoplasts prepared from suspension-cultured cotton cells were infected by incubation with liposome-encapsulated camv virions. during a 1-week culture period the amount of camv nucleic acid as detected by nucleic acid hybridization in the protoplasts increased significantly regardless of whether or not the protoplasts contained vacuoles. in leaves inoculated with ... | 1987 | 16665300 |
| udp-glucose: (1-->3)-beta-glucan synthases from mung bean and cotton: differential effects of ca and mg on enzyme properties and on macromolecular structure of the glucan product. | a re-examination of the kinetic properties of udp-glucose: (1-->3)-beta-glucan (callose) synthases from mung bean seedlings (vigna radiata) and cotton fibers (gossypium hirsutum) shows that these enzymes have a complex interaction with udp-glucose and various effectors. stimulation of activity by micromolar concentrations of ca(2+) and millimolar concentrations of beta-glucosides or other polyols is highest at low (<100 micromolar) udp-glucose concentrations. these effectors act both by raising ... | 1987 | 16665323 |
| osmotic adjustment in cotton (gossypium hirsutum l.) leaves and roots in response to water stress. | the relative magnitude of adjustment in osmotic potential (psi(s)) of water-stressed cotton (gossypium hirsutum l.) leaves and roots was studied using plants raised in pots of sand and grown in a growth chamber. one and three water-stress preconditioning cycles were imposed by withholding water, and the subsequent adjustment in solute potential upon relief of the stress and complete rehydration was monitored with thermocouple psychrometers. both leaves and roots exhibited a substantial adjustmen ... | 1987 | 16665577 |
| cottonseed malate synthase : purification and immunochemical characterization. | malate synthase (ec 4.1.3.2), an enzyme unique to the glyoxylate cycle, was purified to homogeneity from cotyledons of 72-hours, darkgrown cotton (gossypium hirsutum l.) seedlings. homogeneity of the enzyme was assessed by silver staining sds-page gels. purification was accomplished by using a single buffer medium through six steps involving one ammonium sulfate fractionation and chromatography on three columns (sephacryl s-300, deae sephacel, phenyl sepharose). large-scale preparation of glyoxy ... | 1987 | 16665608 |
| cottonseed malate synthase : biogenesis in maturing and germinated seeds. | the activity of malate synthase (ms) (ec 4.1.3.2) appears and increases during cotton (gossypium hirsutum l.) seed maturation, persists through desiccation and imbibition, then increases again following germination. the research reported herein is a comparative study of the synthesis and acquisition of ms into glyoxysomes as they occur in maturing and germinated seeds. rate-zonal centrifugation of cotyledon extracts revealed that the 5 svedberg unit (s) cytosolic form of ms was the only form pre ... | 1987 | 16665609 |
| effect of altered sink: source ratio on photosynthetic metabolism of source leaves. | when seven crop species were grown under identical environmental conditions, decreased sink:source ratio led to a decreased photosynthetic rate within 1 to 3 days in cucumis sativus l., gossypium hirsutum l., and raphanus sativus l., but not in capsicum annuum l., solanum melongena l., phaseolus vulgaris l., or ricinus communis l. the decrease was not associated with stomatal closure. in cotton and cucumber, sink removal led to an increase in starch and sugar content, in glucose 6-phosphate and ... | 1987 | 16665777 |
| generation of a membrane potential by electron transport in plasmalemma-enriched vesicles of cotton and radish. | plasmalemma-enriched vesicles were isolated from cotton roots (gossypium hirsutum l. cv acala san jose 2) and from germinating radish seeds (raphanus sativa l. cv tondo rosso quarantino). when 100 millimolar ascorbate was added to the grinding medium, the addition of ferricyanide to either preparation led to an inside positive membrane potential as measured by the accumulation of thiocyanate. it is suggested that electrons from ascorbate were being transported electrogenically across the membran ... | 1987 | 16665822 |
| disruption of the polar auxin transport system in cotton seedlings following treatment with the defoliant thidiazuron. | the effect of the defoliant thidiazuron (tdz) on basipetal auxin transport in petiole segments isolated from cotton (gossypium hirsutum l. cv lg102) seedlings was examined using the donor/receiver agar block technique. treatment of intact seedlings with tdz at concentrations of 1 micromolar or greater resulted in a dose-dependent inhibition of (14)c-iaa transport in petiole segments isolated 1 or 2 days after treatment. using 100 micromolar tdz, the inhibition was detectable 19 hours after treat ... | 1988 | 16665874 |
| changes in free and conjugated indole 3-acetic acid and abscisic acid in young cotton fruits and their abscission zones in relation to fruit retention during and after moisture stress. | experiments were conducted with field-grown cotton (gossypium hirsutum l.) in 1985 and 1986 to determine effects of water deficit on levels of conjugated indole 3-acetic acid (iaa) and abscisic acid (aba) in young fruits (bolls) and their abscission zones in relation to boll retention. tissues were harvested three times during an irrigation cycle in 1985. they were harvested twice during an irrigation cycle and once after irrigation in 1986 to determine extent of recoveries of measured parameter ... | 1988 | 16665881 |
| abscisic acid movement into the apoplastic solution of water-stressed cotton leaves: role of apoplastic ph. | leaves of cotton (gossypium hirsutum l.) were subjected to overpressures in a pressure chamber, and the exuded sap was collected and analyzed. the exudate contained low concentrations of solutes that were abundant in total leaf extracts, and photosynthetic rates and stomatal conductance were completely unaffected by a cycle of pressurization and rehydration. these criteria and others indicate that the experimental techniques inflicted no damage upon the leaf cells. the ph and abscisic acid (aba) ... | 1988 | 16666007 |
| gradients of intercellular co(2) levels across the leaf mesophyll. | most current photosynthesis models, and interpretations of many wholeleaf co(2) gas exchange measurements, are based on the often unstated assumption that the partial pressure of co(2) is nearly uniform throughout the airspaces of the leaf mesophyll. here we present measurements of co(2) gradients across amphistomatous leaves allowed to assimilate co(2) through only one surface, thus simulating hypostomatous leaves. we studied five species: eucalyptus pauciflora sieb. ex spreng., brassica chinen ... | 1988 | 16666027 |
| response of leaf ontogeny and photosynthetic activity to reproductive growth in cotton. | this study was conducted to determine if reproductive growth in cotton (gossypium hirsutum l.) affects concurrent leaf development. apparent photosynthesis (ap), stomatal conductance (cs), soluble protein (sp), ribulose bisphosphate carboxylase (rubisco), and chlorophyll (chl) were monitored in four main-stem cotton leaves which emerged at approximately 2 week intervals. the leaf which emerged during vegetative growth (48 days after planting) had higher ap, sp, and rubisco levels than that prese ... | 1988 | 16666118 |
| changes in abscisic acid and indoleacetic acid before and after anthesis relative to changes in abscission rates of cotton fruiting forms. | cotton (gossypium hirsutum l.) fruiting forms exhibit pronounced changes, with age, in their probability of abscission. large floral buds rarely abscise, but after anthesis the young fruits (bolls) have a high probability of abscising. abscission rate reaches a peak about 5 to 6 days after anthesis and then gradually decreases. an experiment was conducted to try to determine the reason for the rapid and pronounced increase in probability of abscission just after anthesis. cotton was grown in the ... | 1988 | 16666197 |
| isoosmotic regulation of cotton and peanut at saline concentrations of k and na. | peanut (arachis hypogaea l.) and cotton (gossypium hirsutum) plants were grown for 4 weeks in saline, isoosmotic rooting substrates with different proportions of k and na. isoosmotic media did not affect growth (except at the highest external k concentrations) or estimates of intracellular osmotic pressure in expanding leaves (i.e. osmotic pressure of leaf sap and intracellular osmotic pressure as calculated from pressure-volume curves). in expanded leaves, an increase in the proportion of exter ... | 1988 | 16666244 |
| incorporation of [c]glucose into cell wall polysaccharides of cotton roots: effects of nacl and cacl(2). | cotton (gossypium hirsutum l. cv acala sj-2) seedlings were grown in nutrient solutions with four combinations of nacl (0.1 and 150 millimolar) and cacl(2) (1 and 10 millimolar) for 7 days, and then exposed to [(14)c]glucose for 5 hours. uptake and incorporation of [(14)c]glucose into various cell wall fractions of the root tips were determined. at 1 millimolar ca(2+), treatment with 150 millimolar nacl slightly stimulated uptake but considerably inhibited glucose incorporation into noncellulosi ... | 1988 | 16666336 |
| correlation of stomatal conductance with photosynthetic capacity of cotton only in a co(2)-enriched atmosphere: mediation by abscisic acid? | some evidence indicates that photosynthetic rate (a) and stomatal conductance (g) of leaves are correlated across diverse environments. the correlation between a and g has led to the postulation of a "messenger" from the mesophyll that directs stomatal behavior. because a is a function of intercellular co(2) concentration (c(i)), which is in turn a function of g, such a correlation may be partially mediated by c(i) if g is to some degree an independent variable. among individual sunlit leaves in ... | 1988 | 16666421 |
| characteristics of five new photoautotrophic suspension cultures including two amaranthus species and a cotton strain growing on ambient co(2) levels. | suspension cultures of cotton (gossypium hirsutum), amaranthus cruentus, a. powellii, datura innoxia, and a nicotiana tabacum-n. glutinosa fusion hybrid were adapted to grow photoautotrophically under continuous light. the cotton strain grew with an atmosphere of ambient co(2) (about 0.06 to 0.07% in the culture room) while the other strains required elevated co(2) levels (5%). photoautotrophy was indicated by the requirement for co(2) and for light for growth. the strains grew with doubling tim ... | 1988 | 16666458 |
| correlation between the carbon isotope discrimination in leaf starch and sugars of c(3) plants and the ratio of intercellular and atmospheric partial pressures of carbon dioxide. | carbon isotope discrimination (delta) was analyzed in leaf starch and soluble sugars, which represent most of the recently fixed carbon. plants of three c(3) species (populus nigra l. x p. deltoides marsh., gossypium hirsutum l. and phaseolus vulgaris l.) were kept in the dark for 24 hours to decrease contents of starch and sugar in leaves. then gas exchange measurements were made with constant conditions for 8 hours, and subsequently starch and soluble sugars were extracted for analysis of carb ... | 1988 | 16666476 |
| water transport properties of cortical cells in roots of nitrogen- and phosphorus-deficient cotton seedlings. | growth-limiting deficiencies of n or p substantially decrease the hydraulic conductance of cotton (gossypium hirsutum l.) roots. this shift could result from decreased hydraulic conductivity of cells in the radial flow pathway. a pressure microprobe was used to study water relations of cortical cells in roots of cotton seedlings stressed for n or p. during 10 days of seedling growth on a complete nutrient solution, root cell turgor was stable at 0.4 to 0.5 megapascal, the volumetric elastic modu ... | 1989 | 16666523 |
| relationship between cottonseed malate synthase aggregation behavior and suborganellar location in glyoxysomes and endoplasmic reticulum. | malate synthase (ec 4.1.3.2) (ms), an enzyme unique to the glyoxylate cycle, was studied in cotyledons of dark-grown cotton (gossypium hirsutum, l.) seedlings. ms has generally been regarded as a peripheral membrane protein in glyoxysomes and believed by some to be synthesized on rough er. immunocyto-chemical localization of ms in both in situ and isolated cottonseed glyoxysomes, however, showed that ms was located throughout the matrix of glyoxysomes, not specifically associated with their memb ... | 1989 | 16666538 |
| changes in amide-linked and ester indole-3-acetic acid in cotton fruiting forms during their development. | the concentration of free indoleacetic acid (iaa) is high in cotton (gossypium hirsutum l.) fruiting forms before anthesis, but is low at and for a few days after anthesis. amide-linked and ester iaa were measured in fruiting forms at 9, 6, and 3 days before anthesis; at anthesis; and at 2, 4, 7, and 9 days after anthesis to determine if free iaa decreased because it was converted to a conjugated form. that did not appear to be the case. while the major decrease in free iaa occurred during the 6 ... | 1989 | 16666645 |
| light-induced spectral absorbance changes in relation to photosynthesis and the epoxidation state of xanthophyll cycle components in cotton leaves. | when cotton (gossypium hirsutum l., cv acaia sjc-1) leaves kept in weak light were suddenly exposed to strong red actinic light a spectral absorbance change took place having the following prominent characteristics. (a) it was irreversible within the first four minute period after darkening. (b) the difference in leaf absorbance between illuminated and predarkened leaves had a major peak at 505 nanometers, a minor peak at 465 nanometers, a shoulder around 515 nanometers, and minor troughs at 455 ... | 1989 | 16667067 |
| photosynthetic carbon metabolism in photoautotrophic cell suspension cultures grown at low and high co(2). | photosynthetic carbon metabolism was characterized in four photoautotrophic cell suspension cultures. there was no apparent difference between two soybean (glycine max) and one cotton (gossypium hirsutum) cell line which required 5% co(2) for growth, and a unique cotton cell line that grows at ambient co(2) (660 microliters per liter). photosynthetic characteristics in all four lines were more like c(3) mesophyll leaf cells than the cell suspension cultures previously studied. the pattern of (14 ... | 1989 | 16667210 |
| uptake and metabolism of clomazone in tolerant-soybean and susceptible-cotton photomixotrophic cell suspension cultures. | studies were conducted to determine the uptake and metabolism of the pigment synthesis inhibiting herbicide clomazone in tolerant-soybean (glycine max [l.] merr. cv corsoy) and susceptible-cotton (gossypium hirsutum [l.] cv stoneville 825) photomixotrophic cell suspensions. soybean and cotton on a whole plant level are tolerant and susceptible to clomazone, respectively. preliminary studies indicated that i(50) values for growth, chlorophyll (chl), beta-carotene, and lutein were, respectively, > ... | 1990 | 16667349 |
| responses of transpiration and hydraulic conductance to root temperature in nitrogen- and phosphorus-deficient cotton seedlings. | suboptimal n or p availability and cool temperatures all decrease apparent hydraulic conductance (l) of cotton (gossypium hirsutum l.) roots. the interaction between nutrient status and root temperature was tested in seedlings grown in nutrient solutions. the depression of l (calculated as the ratio of transpiration rate to absolute value of leaf water potential [psi(w)]) by nutrient stress depended strongly on root temperature, and was minimized at high temperatures. in fully nourished plants, ... | 1990 | 16667360 |
| variation among species in the temperature dependence of the reappearance of variable fluorescence following illumination. | the relationship between the thermal dependence of the reappearance of chlorophyll variable fluorescence following illumination and temperature dependence of the apparent michaelis constant (k(m)) of nadh hydroxypyruvate reductase for nadh was investigated in cool and warm season plant species. brancker sf-20 and sf-30 fluorometers were used to evaluate induced fluorescence transients from detached leaves of wheat (triticum aestivum l. cv tam-101), cotton (gossypium hirsutum l. cv paymaster 145) ... | 1990 | 16667518 |
| influence of water deficits on the abscisic acid and indole-3-acetic acid contents of cotton flower buds and flowers. | a field experiment was conducted during the summer of 1988 to test the hypothesis that water deficit affects the abscisic acid (aba) and indole acetic acid (iaa) concentrations in cotton (gossypium hirsutum l.) flower buds in ways that predispose young fruits (bolls) that subsequently develop from them to increased abscission rates. water deficit had little effect on the aba content of flower buds but increased the aba content of flowers as much as 66%. water deficit decreased the concentrations ... | 1990 | 16667566 |
| inhibition of cottonseed choline- and ethanolaminephosphotransferases by calcium during postgerminative growth. | activities of choline- and ethanolaminephosphotransferase (cpt and ept) were reproducibly high in microsomes from imbibed seeds of cotton (gossypium hirsutum, l.). initial studies showed that both activities dramatically declined during postgerminative growth when demand for phosphatidylcholine (pc) and phosphatidylethanolamine (pe) synthesis was high. addition of cacl(2) (0.1 millimolar) or aliquots of supernatant fractions (150,000g, 60 minutes) from cotyledons of 48-hour-old seedlings to imbi ... | 1990 | 16667651 |
| properties of mutant acetolactate synthases resistant to triazolopyrimidine sulfonanilide. | triazolopyrimidine sulfanilides are a class of highly active herbicides whose primary target is acetolactate synthase. spontaneous mutants of tobacco (nicotiana tabacum) (ks-43) and cotton (gossypium hirsutum) (ps-3 and do-2) resistant to triazolopyrimidine sulfonanilide were selected in tissue culture. acetolactate synthase partially purified from the three mutants were 80- to 1000-fold less sensitive to inhibition by the compound compared with the corresponding wild-type enzyme. the mutants al ... | 1990 | 16667692 |
| photosynthetic and respiratory activity of fruiting forms within the cotton canopy. | the supply of photosynthates by leaves for reproductive development in cotton (gossypium hirsutum l.) has been extensively studied. however, the contribution of assimilates derived from the fruiting forms themselves is inconclusive. field experiments were conducted to document the photosynthetic and respiratory activity of cotton leaves, bracts, and capsule walls from anthesis to fruit maturity. bracts achieved peak photosynthetic rates of 2.1 micromoles per square meter per second compared with ... | 1990 | 16667734 |
| site of clomazone action in tolerant-soybean and susceptible-cotton photomixotrophic cell suspension cultures. | studies were conducted to determine the herbicidal site of clomazone action in tolerant-soybean (glycine max [l.] merr. cv corsoy) (sb-m) and susceptible-cotton (gossypium hirsutum [l.] cv stoneville 825) (cot-m) photomixotrophic cell suspension cultures. although a 10 micromolar clomazone treatment did not significantly reduce the terpene or mixed terpenoid content (microgram per gram fresh weight) of the sb-m cell line, there was over a 70% reduction in the chlorophyll (chl), carotenoid (car), ... | 1990 | 16667768 |
| does water deficit stress promote ethylene synthesis by intact plants? | the effect of plant water deficit on ethylene production by intact plants was tested in three species, beans (phaseolus vulgaris l.), cotton (gossypium hirsutum l.) and miniature rose (rosa hybrida l., cv bluesette). compressed air was passed through glass, plant-containing cuvettes, ethylene collected on chilled columns, and subsequently assayed by gas chromatography. the usual result was that low water potential did not promote ethylene production. when plants were subjected to cessation of ir ... | 1990 | 16667895 |
| photosynthetic characterization of photoautotrophic cells cultured in a minimal medium. | photosynthetic properties of photoautotrophic suspensions cultured in a minimal growth medium have been evaluated to determine whether changes have occurred in ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) activity, phosphoenol-pyruvate (pep) carboxylase activity, chlorophyll content, or culture growth. five photoautotrophic lines amaranthus powellii, datura innoxia, glycine max, gossypium hirsutum, and a nicotiana tabacum-nicotiana glutinosa fusion hybrid were grown in a medium with ... | 1990 | 16667897 |
| na/h and k/h antiport in root membrane vesicles isolated from the halophyte atriplex and the glycophyte cotton. | proton fluxes have been followed into and out of membrane vesicles isolated from the roots of the halophyte atriplex nummularia and the glycophyte gossypium hirsutum, with the aid of the deltaph probe [(14)c]methylamine. evidence is presented for the operation of na(+)/h(+) and k(+)/h(+) antiporters in the membranes of both plants. cation supply after a ph gradient has been set up across the vesicle membrane (either as a result of providing atp to the h(+)-atpase or by imposing an artificial ph ... | 1990 | 16667918 |
| purification and characterization of isoperoxidases elicited by aspergillus flavus in cotton ovule cultures. | two anionic isoperoxidases were isolated from media of aspergillus flavus-inoculated cotton (gossypium hirsutum l.) ovule cultures and purified about 150-fold to apparent homogeneity by treatment with cell debris remover and ion exchange chromatography on accell qma medium. these isoperoxidases were present in noninoculated cotton ovule cultures at low levels. the major activity peak (b) represented 90% of the recovered peroxidase activity and was electrophoretically homogeneous. the minor activ ... | 1991 | 16667941 |
| carbon partitioning and export from mature cotton leaves. | the partitioning of carbon in intact, mature cotton (gossypium hirsutum l.) leaves was examined by steady-state (14)co(2) labeling. plants were exposed to dark periods of varying lengths, followed by similar illuminated labeling periods. these treatments produced leaves with a range of starch and soluble sugar contents, carbon exchange, and carbon export rates. export during the illuminated periods was neither highly correlated with photosynthesis nor was export during the illuminated periods si ... | 1991 | 16667956 |
| induction of leaf abscission in cotton is a common effect of urea- and adenine-type cytokinins. | cytokinins of the urea and adenine type induced leaf abscission in young cotton (gossypium hirsutum) plants in the following order of activity: n-phenyl-n'-1,2,3-thiadiazol-5-ylurea (thidiazuron) > n-phenyl-n'-(2-chloro-4-pyridyl)urea > isopentenyladenine >/= 6-benzyladenine > zeatin = dihydrozeatin > kinetin. it is suggested that ethylene production is implicated in this response because it was stimulated by the compounds in cotton leaf discs with nearly the same effectiveness. moreover, simila ... | 1991 | 16667957 |
| ethylene-induced leaf abscission in cotton seedlings : the physiological bases for age-dependent differences in sensitivity. | the speed of ethylene-induced leaf abscission in cotton (gossypium hirsutum l. cv lg-102) seedlings is dependent on leaf position (i.e. physiological age). fumigation of intact seedlings for 18 hours with 10 microliters per liter of ethylene resulted in 40% abscission of the still-expanding third true (3 degrees ) leaves but had no effect on the fully expanded first true (1 degrees ) leaves. after 42 hours of fumigation with 50 microliters per liter of ethylene, total abscission of the 3 degrees ... | 1991 | 16667967 |
| intracellular localization of phosphatidylcholine and phosphatidylethanolamine synthesis in cotyledons of cotton seedlings. | subfractionation of clarified cotyledon homogenates of cotton (gossypium hirsutum l.) seedlings on sucrose gradients revealed a single coincident peak of cholinephosphotransferase (ec 2.7.8.2) (cpt) and ethanolaminephosphotransferase (ec 2.7.8.1) (ept) activities, which equilibrated with the main peak of antimycin a-insensitive nadh:cytochrome c reductase (ccr) activity. the small percentage of cpt and ept activities (less than 5% of the total) in glyoxysome-enriched pellets equilibrated with cy ... | 1991 | 16667983 |
| cultured ovules as models for cotton fiber development under low temperatures. | cotton fibers (gossypium hirsutum l.) developing in vitro responded to cyclic temperature change similarly to those of field-grown plants under diumal temperature fluctuations. absolute temperatures and rates of temperature change were similar under both conditions. in vitro fibers exhibited a "growth ring" for each time the temperature cycled to 22 or 15 degrees c. rings were rarely detected when the low point was 28 degrees c. the rings seemed to correspond to alternating regions of high and l ... | 1991 | 16667986 |
| direct photolabeling with [p]udp-glucose for identification of a subunit of cotton fiber callose synthase. | we have identified a 52 kilodalton polypeptide as being a likely candidate for the catalytic subunit of the udp-glucose: (1-->3)-beta-glucan (callose) synthase of developing fibers of gossypium hirsutum (cotton). such a polypeptide migrates coincident with callose synthase during glycerol gradient centrifugation in the presence of edta, and can be directly photolabeled with the radioactive substrate, alpha-[(32)p]udp-glucose. interaction with the labeled probe requires ca(2+), a specific activat ... | 1991 | 16668019 |
| effects of salinity on stomatal conductance, photosynthetic capacity, and carbon isotope discrimination of salt-tolerant (gossypium hirsutum l.) and salt-sensitive (phaseolus vulgaris l.) c(3) non-halophytes. | the effects of salinity on growth, stomatal conductance, photosynthetic capacity, and carbon isotope discrimination (delta) of gossypium hirsutum l. and phaseolus vulgaris l. were evaluated. plants were grown at different nacl concentrations from 10 days old until mature reproductive structures were formed. plant growth and leaf area development were strongly reduced by salinity, in both cotton and bean. stomatal conductance also was reduced by salinity. the delta always declined with increasing ... | 1991 | 16668029 |
| acetolactate synthase inhibiting herbicides bind to the regulatory site. | acetolactate synthase from spontaneous mutants of tobacco (nicotiana tabacum; ks-43 and sk-53) and cotton (gossypium hirsutum; ps-3, psh-91, and do-2) selected in tissue culture for resistance to a triazolopyrimidine sulfonanilide showed varying degrees of insensitivity to feedback inhibitor(s) valine and/or leucine. a similar feature was evident in the enzyme isolated from chlorsulfuron-resistant weed biotypes, kochia scoparia and stellaria media. dual inhibition analyses of triazolopyrimidine ... | 1991 | 16668171 |
| root restriction as a factor in photosynthetic acclimation of cotton seedlings grown in elevated carbon dioxide. | interactive effects of root restriction and atmospheric co(2) enrichment on plant growth, photosynthetic capacity, and carbohydrate partitioning were studied in cotton seedlings (gossypium hirsutum l.) grown for 28 days in three atmospheric co(2) partial pressures (270, 350, and 650 microbars) and two pot sizes (0.38 and 1.75 liters). some plants were transplanted from small pots into large pots after 20 days. reduction of root biomass resulting from growth in small pots was accompanied by decre ... | 1991 | 16668232 |
| acclimation of co(2) assimilation in cotton leaves to water stress and salinity. | cotton (gossypium hirsutum l. cv acala sj2) plants were exposed to three levels of osmotic or matric potentials. the first was obtained by salt and the latter by withholding irrigation water. plants were acclimated to the two stress types by reducing the rate of stress development by a factor of 4 to 7. co(2) assimilation was then determined on acclimated and nonacclimated plants. the decrease of co(2) assimilation in salinity-exposed plants was significantly less in acclimated as compared with ... | 1991 | 16668429 |
| evidence for light-dependent recycling of respired carbon dioxide by the cotton fruit. | conservation of respired co(2) by an efficient recycling mechanism in fruit could provide a significant source of c for yield productivity. however, the extent to which such a mechanism operates in cotton (gossypium hirsutum l.) is unknown. therefore, a combination of co(2) exchange, stable c isotope, and chlorophyll (chl) fluorescence techniques were used to examine the recycling of respired co(2) in cotton fruit. respiratory co(2) losses of illuminated fruit were reduced 15 to 20% compared wit ... | 1991 | 16668437 |
| sequence of the gossypium hirsutum d-genome alloallele of legumin a and its mrna. | 1991 | 16668521 | |
| high performance liquid chromatography analysis of carbohydrates of cotton-phloem sap and of honeydew produced by bemisia tabaci feeding on cotton. | phloem sap from cotton (gossypium hirsutum l.) was collected from young and mature leaves by the aphid-stylet technique. exudate was analyzed for carbohydrates by hplc using sensitive pulsed amperometric detection. the predominant carbohydrate present (>90%) was identified as sucrose. a second, unidentified compound that was not one of the more commonly translocated sugars was detected in mature leaves. carbohydrates in honeydew produced by the sweet-potato whitefly (bemisia tabaci [genn.]) feed ... | 1992 | 16668706 |
| regulation of photosynthesis by end-product accumulation in leaves of plants storing starch, sucrose, and hexose sugars. | in the present study, leaves of different plant species were girdled by the hot wax collar method to prevent export of assimilates. photosynthetic activity of girdled and control leaves was evaluated 3 to 7 days later by two methods: (a) carbon exchange rate (cer) of attached leaves was determined under ambient co(2) concentrations using a closed gas system, and (b) maximum photosynthetic capacity (a(max)) was determined under 3% co(2) with a leaf disc o(2) electrode. starch, hexoses, and sucros ... | 1992 | 16669056 |
| molecular variability of spodoptera frugiperda (lepidoptera: noctuidae) populations associated to maize and cotton crops in brazil. | the molecular variability among 10 populations of spodoptera frugiperda (j.e. smith), collected from maize, zea mays l., or cotton gossypium hirsutum l. crops located at distinctive geographical regions in brazil, was assessed through random amplification of polymorphic dna (rapd)-polymerase chain reaction (pcr). in total, 208 rapd markers were evaluated, and 98% of them were polymorphic. the mean genetic similarity was 0.6621 and 0.2499 by the simple matching and jaccard matrices, respectively. ... | 2006 | 16686155 |
| sampling methods, dispersion patterns, and fixed precision sequential sampling plans for western flower thrips (thysanoptera: thripidae) and cotton fleahoppers (hemiptera: miridae) in cotton. | a 2-yr field study was conducted to examine the effectiveness of two sampling methods (visual and plant washing techniques) for western flower thrips, frankliniella occidentalis (pergande), and five sampling methods (visual, beat bucket, drop cloth, sweep net, and vacuum) for cotton fleahopper, pseudatomoscelis seriatus (reuter), in texas cotton, gossypium hirsutum (l.), and to develop sequential sampling plans for each pest. the plant washing technique gave similar results to the visual method ... | 2006 | 16686161 |
| analysis of ests from multiple gossypium hirsutum tissues and identification of ssrs. | in an effort to expand the gossypium hirsutum l. (cotton) expressed sequence tag (est) database, ests representing a variety of tissues and treatments were sequenced. assembly of these sequences with ests already in the est database (dbest, genbank) identified 9675 cotton sequences not present in genbank. statistical analysis of a subset of these ests identified genes likely differentially expressed in stems, cotyledons, and drought-stressed tissues. annotation of the differentially expressed cd ... | 2006 | 16699550 |
| isolation of the promoter of a cotton beta-galactosidase gene (ghgal1) and its expression in transgenic tobacco plants. | beta-galactosidases (ec 3.2.1.23) constitute a widespread family of glycosyl hydrolases in plants and are thought to be involved in metabolism of cell wall polysaccharides. a cdna of the cotton (gossypium hirsutum) beta-galactosidase gene, designated ghgal1, has previously been identified and its transcripts are highly abundant at the elongation stage of the cotton fiber. to examine the temporal and spatial control of ghgal1 expression, a transcriptional fusion of the ghgal1 promoter region (177 ... | 2006 | 16704113 |
| an experiment using neutron activation analysis and a rare earth element to mark cotton plants and two insects that feed on them. | studies on insect dispersal and other behaviors can benefit from using markers that will not alter flight and fitness. rare earth elements, such as samarium (sm), have been used as ingested markers of some insects and detected using neutron activation analysis (naa). in this study, samarium nitrate hexahydrate was mixed into artificial diet for boll weevils, anthonomus grandis grandis boheman (coleoptera: curculionidae), at different dosages and in water used to irrigate cotton, gossypium hirsut ... | 2006 | 16713273 |
| effect of racemic and (+)- and (-)-gossypol on the survival and development of helicoverpa zea larvae. | gossypol is a sesquiterpene that occurs naturally in seed and other parts of the cotton plant. because of restricted rotation around the binaphthyl bond, it occurs naturally as enantiomeric mixtures with (+)-gossypol to (-)-gossypol ratios that vary between 97:3 and 31:69. commercial cotton varieties (gossypium hirsutum) normally exhibit an approximate 3:2 ratio. (+)-gossypol is significantly less toxic than (-)-gossypol to nonruminant animals; thus, cottonseed containing high levels of (+)-goss ... | 2006 | 16739016 |
| the cloning and sequencing of a cdna encoding a wd repeat protein in cotton (gossypium hirsutum l.). | in this research, one 1156 bp cdna containing full open reading frame and encoding a novel 24-kda protein with four tandem wd repeat motifs was cloned from cotton, therefore was named ghwdr and the genbank accession number is ay870657. by search of ghwdr cdna and amino acid sequences in the database, we found that ghwdr and osjnba0003g23.2 from oryza sativa show 90% sequence identity and 84% identity to wd-repeat protein from arabidopsis thaliana, and also has high sequence identity to other wd ... | 2006 | 16753817 |
| glyphosate-induced anther indehiscence in cotton is partially temperature dependent and involves cytoskeleton and secondary wall modifications and auxin accumulation. | yield reduction caused by late application of glyphosate to glyphosate-resistant cotton (gossypium hirsutum; grc) expressing cp4 5-enol-pyruvylshikmate-3-p synthase under the cauliflower mosaic virus-35s promoter has been attributed to male sterility. this study was aimed to elucidate the factors and mechanisms involved in this phenomenon. western and tissue-print blots demonstrated a reduced expression of the transgene in anthers of grc compared to ovules of the same plants. glyphosate applicat ... | 2006 | 16766672 |
| influence of cytokinins, auxins and polyamines on in vitro mass multiplication of cotton (gossypium hirsutum l. cv. svpr2). | in the present investigation, the influence of different forms of cytokinins, auxins and polyamines were tested for mass multiplication and regeneration of cotton. initially, for the identification of effective concentration for multiple shoot induction, various concentrations of bap, kin and 2ip along with iaa and naa were tested. among tested concentrations, media fortified with ms salts; b5 vitamins; 30 g/l, glucose; 2.0 mg/l, 2ip; 2.0 mg/l, iaa and 0.7 % agar showed best response for multipl ... | 2006 | 16784123 |
| agrobacterium-mediated transformation of cotton (gossypium hirsutum l. cv. zhongmian 35) using glyphosate as a selectable marker. | the most economically significant chinese cotton cultivar (gossypium hirsutum l. cv. zhongmian 35) was transformed via agrobacterium tumefaciens-mediated dna transfer. the aroa-m1 gene that confers resistance to the glyphosate was fused with a chloroplast-transit peptide of arabidopsis thaliana 5-enolpyruvyl-3-phosphoshikimate synthase (asp) and expressed in cotton plants under the control of a camv35s promoter. transgenic plants were directly selected on medium containing glyphosate. thirty-fou ... | 2006 | 16799756 |
| the absolute configuration of (-)-3-hydroxy-alpha-calacorene. | 3-hydroxy-alpha-calacorene was identified in extracts from cold-shocked seedlings of cotton (gossypium hirsutum l.) and kenaf (hibiscus cannabinus l.), both of which are members of the malvaceae family. (-)-3-hydroxy-alpha-calacorene was isolated from heterotheca inuloides cass. (asteraceae). hplc on a chiral stationary phase column showed that the 3-hydroxy-alpha- calacorene from cotton and kenaf had the same relative configuration, while that from h. inuloides was of the opposite configuration ... | 2006 | 16806327 |
| captures of boll weevils (coleoptera: curculionidae) in traps associated with different habitats. | programs to eradicate the boll weevil, anthonomus grandis grandis boheman, from cotton, gossypium hirsutum l., in the united states rely heavily on pheromone traps for monitoring weevil populations in both active and posteradication maintenance programs. modifications to trapping protocols that increase trap effectiveness should contribute to this eradication effort. between october 1996 and may 1997 and between september 1997 and april 1998, we compared trap effectiveness, indicated by the numb ... | 2006 | 16813308 |
| effect of resistance to bacillus thuringiensis cotton on pink bollworm (lepidoptera: gelechiidae) response to sex pheromone. | fitness costs associated with resistance to transgenic crops producing toxins from bacillus thuringiensis (bt) could reduce male response to pheromone traps. such costs would cause underestimation of resistance frequency if monitoring was based on analysis of males caught in pheromone traps. to develop a dna-based resistance monitoring program for pink bollworm, pectinophora gossypiella (saunders) (lepidoptera: gelechiidae), we compared the response to pheromone traps of males with and without c ... | 2006 | 16813335 |
| soil organic carbon sequestration in cotton production systems of the southeastern united states: a review. | past agricultural management practices have contributed to the loss of soil organic carbon (soc) and emission of greenhouse gases (e.g., carbon dioxide and nitrous oxide). fortunately, however, conservation-oriented agricultural management systems can be, and have been, developed to sequester soc, improve soil quality, and increase crop productivity. our objectives were to (i) review literature related to soc sequestration in cotton (gossypium hirsutum l.) production systems, (ii) recommend best ... | 2006 | 16825457 |
| carbon supply and storage in tilled and nontilled soils as influenced by cover crops and nitrogen fertilization. | soil carbon (c) sequestration in tilled and nontilled areas can be influenced by crop management practices due to differences in plant c inputs and their rate of mineralization. we examined the influence of four cover crops {legume [hairy vetch (vicia villosa roth)], nonlegume [rye (secale cereale l.)], biculture of legume and nonlegume (vetch and rye), and no cover crops (or winter weeds)} and three nitrogen (n) fertilization rates (0, 60 to 65, and 120 to 130 kg n ha(-1)) on c inputs from cove ... | 2006 | 16825471 |
| foliar washoff potential and simulated surface runoff losses of trifloxysulfuron in cotton. | the surface runoff potential of trifloxysulfuron {n-[(4,6-dimethoxy-2-pyrimidinyl)carbamoyl]-3-(2,2,2-trifluoroethoy)-pyridin-2-sulfonamide sodium salt} in cotton (gossypium hirsutum l.) production systems has not been evaluated. the objectives of this study were to (i) determine sorption/desorption coefficients for trifloxysulfuron; (ii) quantify foliar washoff of trifloxysulfuron when applied to cotton at the five-leaf stage; and (iii) determine the surface runoff potential of trifloxysulfuron ... | 2006 | 16848537 |
| the cotton fiber zinc-binding domain of cellulose synthase a1 from gossypium hirsutum displays rapid turnover in vitro and in vivo. | little is known about the assembly and turnover of cellulose synthase complexes commonly called rosettes. recent work indicates that rosette assembly could involve the dimerization of cesa (cellulose synthase catalytic subunit) proteins regulated by the redox state of the cesa zinc-binding domain (znbd). several studies in the 1980s led to the suggestion that synthase complexes may have very short half-lives in vivo, but no recent work has directly addressed this issue. in the present work, we s ... | 2006 | 16873546 |
| molecular cloning of a peroxidase gene from poplar and its expression in response to stress. | to elucidate the precise functions of peroxidase in poplar (populus alba x p. tremula var. glandulosa), we cloned a peroxidase gene (popod1) from poplar suspension culture cells and examined its expression pattern in response to various stresses. popod1 showed the highest homology with a bacterial-induced peroxidase gene from cotton (gossypium hirsutum l.). the popod1 gene encodes a putative 316 amino acid protein with an n-terminal signal peptide of 23 residues. the dna blot analysis indicated ... | 2006 | 16877325 |
| accumulation of genome-specific transcripts, transcription factors and phytohormonal regulators during early stages of fiber cell development in allotetraploid cotton. | gene expression during the early stages of fiber cell development and in allopolyploid crops is poorly understood. here we report computational and expression analyses of 32 789 high-quality ests derived from gossypium hirsutum l. texas marker-1 (tm-1) immature ovules (gh_tmo). the ests were assembled into 8540 unique sequences including 4036 tentative consensus sequences (tcs) and 4504 singletons, representing approximately 15% of the unique sequences in the cotton est collection. compared with ... | 2006 | 16889650 |
| effect of monosodium methanarsonate application on cuticle wax content of cocklebur and cotton plants. | leaf cuticle waxes were extracted from monosodium methanearsonate (msma)-resistant (r) and -susceptible (s) common cocklebur (xanthium strumarium l.) and cotton (gossypium hirsutum l.) plants at 0, 3, 5, and 7 days after treatment (dat) following 1x and 2x msma applications. wax constituents were analyzed by gas chromatography (gc) with flame ionization detection and compared to alkane and alcohol standards of carbon lengths varying from c21 to c30. differences in waxes were calculated and repor ... | 2006 | 16893783 |
| how do leaf hydraulics limit stomatal conductance at high water vapour pressure deficits? | a reduction in leaf stomatal conductance (g) with increasing leaf-to-air difference in water vapour pressure (d) is nearly ubiquitous. ecological comparisons of sensitivity have led to the hypothesis that the reduction in g with increasing d serves to maintain leaf water potentials above those that would cause loss of hydraulic conductance. a reduction in leaf water potential is commonly hypothesized to cause stomatal closure at high d. the importance of these particular hydraulic factors was te ... | 2006 | 16898024 |
| the current status and environmental impacts of glyphosate-resistant crops: a review. | glyphosate [n-(phosphonomethyl) glycine]-resistant crops (grcs), canola (brassica napus l.), cotton (gossypium hirsutum l.), maize (zea mays l.), and soybean [glycine max (l.) merr.] have been commercialized and grown extensively in the western hemisphere and, to a lesser extent, elsewhere. glyphosate-resistant cotton and soybean have become dominant in those countries where their planting is permitted. effects of glyphosate on contamination of soil, water, and air are minimal, compared to some ... | 2006 | 16899736 |
| [spectral characteristics and the structure of chloroplasts upon blocking the early stages of chlorophyll biosynthesis]. | the cotton mutant xantha (gossypium hirsutum l.) with the blocked synthesis of 5-aminolevulinic acid in the light has been shown to accumulate chlorophyll 30 times less than the parent type. in chloroplasts of the mutant xantha, the formation of the membrane system is blocked at the earliest stages, mainly at the stage of bubbles and single short thylakoids. only light-harvesting chlorophyll-a/b-protein complexes i and ii with chlorophyll fluorescence maxima at 728 and 681 nm, respectively, are ... | 2006 | 16909851 |
| cloning and functional analysis of the novel gene ghdbp3 encoding a dre-binding transcription factor from gossypium hirsutum. | a novel cdna encoding dre-binding transcription factor, designated ghdbp3, was cloned from gossypium hirsutum. this protein was classified into a-4 group of dreb subfamily based on multiple sequence alignment and phylogenetic characterization. semiquantitative rt-pcr showed that ghdbp3 was expressed in the leaves, cotyledons, roots and stems of 2-week-old cotton seedlings under non-stress conditions and was greatly induced in the cotton cotyledons by drought, nacl, low temperature and aba treatm ... | 2006 | 16935362 |
| short-range dispersal and overwintering habitats of boll weevils (coleoptera: curculionidae) during and after harvest in the subtropics. | field experiments in the subtropical lower rio grande valley of texas were conducted to determine the extent of adult boll weevil, anthonomus grandis grandis boheman (coleoptera: curculionidae), dispersal from cotton, gossypium hirsutum l., fields during harvest operations and the noncotton-growing ("overwinter") period between 1 september and 1 february. using unbaited large capacity boll weevil traps placed at intervals extending outward from commercial field edges, boll weevils did not move i ... | 2006 | 16937667 |
| qtl mapping for resistance to root-knot nematodes in the m-120 rnr upland cotton line (gossypium hirsutum l.) of the auburn 623 rnr source. | root-knot nematodes meloidogyne incognita (kofoid and white) can cause severe yield loss in cotton (gossypium hirsutum l.). the objectives of this study were to determine the inheritance and genomic location of genes conferring root-knot nematode resistance in m-120 rnr, a highly resistant g. hirsutum line with the auburn 623 rnr source of resistance. utilizing two interspecific f(2) populations developed from the same m-120 rnr by gossypium barbadense (cv. pima s-6) cross, genome-wide scanning ... | 2006 | 16960714 |
| soil microbial activity is affected by roundup weathermax and pesticides applied to cotton (gossypium hirsutum). | adoption of glyphosate-based weed control systems has led to increased use of the herbicide with continued use of additional pesticides. combinations of pesticides may affect soil microbial activity differently than pesticides applied alone. research was conducted to evaluate the influence of glyphosate-based cotton pest management systems on soil microbial activity. soil was treated with commercial formulations of trifluralin, aldicarb, and mefenoxam + pentachloronitrobenzene (pcnb) with or wit ... | 2006 | 16968086 |
| the american cotton rat: a novel model for pulmonary tuberculosis. | several animal models are used to study mycobacterium tuberculosis (mtb) infections, but none is a fully ideal model of human disease. the american cotton rat is an excellent model for the study of several human viral and bacterial respiratory infectious diseases, but until now has not been reported to be a model with mtb infection. preliminary experiments were designed in which two species of cotton rats (sigmodon hispidus and sigmodon fulviventer) received respiratory challenges with m. tuberc ... | 2007 | 16973421 |
| infraspecific dna methylation polymorphism in cotton (gossypium hirsutum l.). | cytosine methylation is important in the epigenetic regulation of gene expression and development in plants and has been implicated in silencing duplicate genes after polyploid formation in several plant groups. relatively little information exists, however, on levels and patterns of methylation polymorphism (mp) at homologous loci within species. here we explored the levels and patterns of methylation-polymorphism diversity at ccgg sites within allotetraploid cotton, gossypium hirsutum, using a ... | 2006 | 16987937 |
| cotton (gossypium hirsutum l.). | considering the economic importance of cotton in many developing and developed countries, there is an urgent need to accelerate the application of biotechnological tools to address the problems associated with the production of this crop and to improve the quality of fiber and seed. this requires a simple yet robust gene delivery/transformant recovery system. a protocol for the production of transgenic cotton plants was refined in our laboratory. it involves agrobacterium-mediated transformation ... | 2006 | 16988351 |
| designing and transgenic expression of melanin gene in tobacco trichome and cotton fiber. | in streptomyces antibioticus, there are two genes tyra and orf438 required for the melanin biogenesis. to investigate whether expression of these two genes in cotton can change cotton fiber colour, we modified the tyra and orf438 genes to make their codon usage closer to the codon preference of cotton fiber genes. the resulting versions of these two genes were referred to as dtyra and dorf438, respectively. vacuolar targeting signals were also added to their ends. under the cotton fiber specific ... | 2007 | 17006798 |
| dna screening reveals pink bollworm resistance to bt cotton remains rare after a decade of exposure. | transgenic crops producing toxins from the bacterium bacillus thuringiensis (bt) kill insect pests and can reduce reliance on insecticide sprays. although bt cotton (gossypium hirsutum l.) and bt corn (zea mays l.) covered 26 million ha worldwide in 2005, their success could be cut short by evolution of pest resistance. monitoring the early phases of pest resistance to bt crops is crucial, but it has been extremely difficult because bioassays usually cannot detect heterozygotes harboring one all ... | 2006 | 17066779 |
| genetic variation for resistance to bacillus thuringiensis toxins in helicoverpa zea (lepidoptera: noctuidae) in eastern north carolina. | to evaluate resistance to bacillus thuringiensis berliner (bt) toxins, adult female bollworms, helicoverpa zea (boddie) (lepidoptera: noctuidae), were collected from four light trap locations in two eastern north carolina counties from august to october during 2001 and 2002. females were allowed to oviposit, and upon hatching, 24 neonates from each female (f1 lines) were screened for survival and growth rate on each of three diets: non-bt diet, diet containing 5.0 microg/ml cry1ac toxin, or diet ... | 2006 | 17066814 |