| 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 |
| storage protein accumulation patterns in somatic embryos of cotton (gossypium hirsutum l.). | the storage protein content of somatic embryos of gossypium hirsutum l. cv. coker 201 was determined using extinction level, antigen/antibody association detection methods. mature storage protein was first detected in early globular-stage somatic embryos at a total concentration of 0.36% of the embryo protein mass. tulip-stage and mature somatic embryos were comprised of 3.0% and 1.3% mature storage protein, respectively. maximum storage protein synthesis was found to occur during early globular ... | 1987 | 24248439 |
| photosynthesis of cotton plants exposed to elevated levels of carbon dioxide in the field. | the cotton (gossypium hirsutum l.) plant responds to a doubling of atmospheric co2 with almost doubled yield. gas exchange of leaves was monitored to discover the photosynthetic basis of this large response. plants were grown in the field in open-top chambers with ambient (nominally 350 μl/l) or enriched (nominally either 500 or 650 μl/l) concentrations of atmospheric co2. during most of the season, in fully-irrigated plants the relationship between assimilation (a) and intercellular co2 concent ... | 1987 | 24435687 |
| 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 |
| somatic embryogenesis from leaf and petiole callus cultures of gossypium hirsutum l. | leaf discs from four strains and petioles from six strains of gossypium hirsutum were cultured on a variety of media. callus formed from explants on all media, though embryogenesis was highly specific. embryos formed from only three strain x media combinations. a small percentage of these embryos developed into plantlets. these results demonstrate that cotton plants can be obtained from leaf tissue explants. | 1986 | 24248405 |
| the conditions required to isolate and maintain viable cotton (gossypium hirsutum l.) microspores. | cultural systems developed for the successful production of haploid plants from anther and microspore culture of a number of species are lethal to cotton microspores. components of these systems were examined individually and in simple combinations to determine their specific effect on cotton microspore viability during isolation and culture. an organically buffered ph of 7.0 was critical for survival. the addition of potassium salts, near standard concentrations used for other species, enhanced ... | 1986 | 24248391 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| some characteristics of peroxidase secreted by cotton ovule cultures. | cotton (gossypium hirsutum l.) ovule cultures secreted a soluble peroxidase into the surrounding medium, resulting in a 200-fold increase in this activity during the 30-day growth period. the peroxidase activity was thermostable from 4°c to 60°c and displayed a ph optimum of 5.5 to 6.0. the ovule peroxidase was susceptible to periodate treatment and very resistant to protease digestion. the data suggest that the peroxidase activity is a glycoprotein. interpretation of peroxidase data may be comp ... | 1986 | 24248293 |
| short-term storage of cotton pollen. | several methods of storing cotton pollen (gossypium hirsutum l.) were evaluated. a successful pollen storage method that maintains fertility would enhance the crossing of breeding materials. storing pollen at ultra-low temperatures in liquid nitrogen or at 5°c was not successful. no storage method maintained pollen fertility for more than 72 h. cotton pollen did maintain adequate fertility up to 24 h at 10 and 15°c, at both low and high humidity when the pollen was stored in the detached flowers ... | 1986 | 24248291 |
| 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 |
| 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 |
| 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 |
| characterization of somatic embryogenesis and plant regeneration in cotton (gossypium hirsutum l.). | seventeen cultivars of cotton (gossypium hirsutum l.) were evaluated for callus initiation and maintenance using 3 initiation media and 3 maintenance media. after a series of transfers of a 3% glucose media, calli were placed on a 3% sucrose medium. after several weeks calli were observed for the presence of embryo-like structures. cultivars coker 201 and coker 315 were identified as embryogenic. embryogenic callus has since been routinely obtained within 6 weeks by initiating callus on glucose ... | 1986 | 24248126 |
| 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 |
| 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 |
| 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 |
| abscisic acid induction of cloned cotton late embryogenesis-abundant (lea) mrnas. | earlier studies found that cotton (gossypium hirsutum l.) cotyledons contain several mrnas which are more abundant during late embryogenesis than in mid-embryogenesis or early germination. they are here termed 'late embryogenesis-abundant' mrnas, encoded by lea loci. complementary dna clones for 18 such mrna sequences, defined at a hybridization criterion of tm-15°c, were identified in a mature embryo cdna library by differential cdna hybridization. at a lower hybridization criterion, some seque ... | 1986 | 24302301 |
| isolation, culture, and cell division in cotyledon protoplasts of cotton (gossypium hirsutum and g. barbadense). | protoplasts were isolated from cotyledons and foliage leaves of cotton (gossypium hirsutum and g. barbadense). cotyledon protoplasts were larger and responded to culture better than leaf protoplasts. cotyledon derived protoplasts regenerated cell walls and formed microcolonies of 2-3 cells in g. hirsutum and 5-8 cells in g. barbadense. however, the microcolonies did not grow beyond this stage. protoplast yield and viability, cell wall regeneration and cell division were influenced by several fac ... | 1986 | 24248051 |
| effect of pollen-style interaction on the pollen tube growth of gossypium hirsutum. | all possible crosses among 5 strains of gossypium hirsutum were made, and the pollen tubes were grown in vivo for 4 h before being fixed, stained and measured. temperatures ranging from 18.5 to 40.0 °c were tested for pollen germination and pollen tube growth. the optimal temperature for pollen tube growth was 30.0 °c. relative humidity levels of 0 to 100% were used as a pre-pollination treatment of the pollen. significant differences among the mean pollen tube length of the strains occurred due ... | 1986 | 24247777 |
| recovery of soluble proteins from glanded cotton tissues with amines. | a simple soluble protein extraction method was developed for glanded cotton (gossypium hirsutum l.) tissues. gossypol, a major component of glands, is known to crosslink and precipitate proteins in cotton tissue homogenates. established phenolic removal reagents were evaluated as gossypol binding agents and found to be less than effective in enhancing cotton leaf-soluble protein recovery. several other amines, including a number of affinity support bound amines, were tested and found relatively ... | 1986 | 3706729 |
| β-glucanases in developing cotton (gossypium hirsutum l.) fibres. | cotton fibres possess several β-glucanase activities which appear to be associated with the cell wall, but which can be partially solubilised in buffers. the main activity detected was that of an exo-(1→3)-β-d-glucanase (ec 3.2.1.58) but which also had the characteristics of a β-glucosidase (ec 3.2.1.21). endo-(1→3)-β-d-glucanase activity (ec 3.2.1.39) and much lower levels of (1→4)-β-d-glucanase activity were also detected. the exo-(1→3)-β-glucanase showed a maximum late on (40 days post-anthes ... | 1985 | 24241619 |
| genetic analysis of some seed quality characters in upland cotton (gossypium hirsutum l.). | a set of diallel crosses involving ten parents was evaluated over two locations to determine the genetic control of protein per cent, oil per cent, seed index, percentage of mature seeds and number of seeds per boll. the analysis of pooled data showed that percentage of mature seeds was controlled by additive (d) and non-additive (h1 and h2) genetic effects. overdominance was noticed. for seed index the d component measuring additive, and the h2 component measuring dominance, variation were sign ... | 1985 | 24247349 |
| 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 |
| 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 |
| 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 |
| reversibility of photosynthetic inhibition in cotton after long-term exposure to elevated co(2) concentrations. | cotton (gossypium hirsutum l. cv stoneville 213) was grown at 350 and 1000 microliters per liter co(2). the plants grown at elevated co(2) concentrations contained large starch pools and showed initial symptoms of visible physical damage. photosynthetic rates were lower than expected based on instantaneous exposure to high co(2).a group of plants grown at 1000 microliters per liter co(2) was switched to 350 microliters per liter co(2). starch pools and photosynthetic rates were monitored in the ... | 1985 | 16664293 |
| accumulation of heat shock proteins in field-grown cotton. | cotton (gossypium hirsutum l.) plants grown under field water deficits exhibited an 80 to 85% reduction in leaf area index, plant height, and dry matter accumulation compared with irrigated controls. midday photosynthetic rates of dryland plants decreased 2-fold, and canopy temperatures increased to 40 degrees c at 80 days after planting compared with canopy temperatures of 30 degrees c for irrigated plants. leaves from dryland plants which had exhibited canopy temperatures of 40 degrees c for s ... | 1985 | 16664252 |
| involvement of ethylene in the action of the cotton defoliant thidiazuron. | the effect of the defoliant thidiazuron (n-phenyl-n'-1,2,3-thiadiazol-5-ylurea) on endogenous ethylene evolution and the role of endogenous ethylene in thidiazuron-mediated leaf abscission were examined in cotton (gossypium hirsutum l. cv stoneville 519) seedlings. treatment of 20- to 30-day-old seedlings with thidiazuron at concentrations equal to or greater than 10 micromolar resulted in leaf abscission. at a treatment concentration of 100 micromolar, nearly total abscission of the youngest le ... | 1985 | 16664229 |
| rhythmicity in cotton seedlings : rhythmic ethylene production as affected by silver ions and as related to other rhythmic processes. | ethylene production by detached cotyledons of cotton (gossypium hirsutum l.) seedlings grown under cycles of 12 h darkness and 12 h light has been shown to be rhythmic, with a minimum and maximum 4 and 16 h, respectively after the start of the cycle (rikin, chalutz and anderson, 1984, plant physiol. 75, 493-495). treatment with silver ions stimulated the rhythmic ethylene production in both regular and "inverted" cycles (i.e. dark period changed to light period, and vice versa). the rate of the ... | 1985 | 24249343 |
| ultrastructure and chemistry of soluble and polymeric lipids in cell walls from seed coats and fibres of gossypium species. | electron-microscopic examination in conjunction with extraction procedures and chemical analysis have confirmed that a suberin-like lipid biopolymer is located within the concentric polylamellate layers found in the secondary cell walls of green cotton fibres (gossypium hirsutum cv. green lint). a polymer of similar ultrastructure and chemical constitution also occurs mainly in the secondary seed-coat walls of the outer epidermis of both green and white varieties of g. hirsutum. the suberins com ... | 1985 | 24249333 |
| osmoregulation in cotton in response to water stress : iii. effects of phosphorus fertility. | cotton (gossypium hirsutum) (l.) was grown in a sand and nutrient solution system at two levels of phosphorus (0.5 and 5.0 millimolar). within each phosphorus treatment, plants were either watered daily or acclimated to water stress by subjection to several water stress cycles.stress acclimation increased leaf starch at the low phosphorus level, but not at the high phosphorus level. high phosphorus increased leaf sucrose and glucose concentration in both acclimated and nonacclimated plants, but ... | 1985 | 16664048 |
| abscisic acid and cutout in cotton. | a decline in growth, flowering, and boll (fruit) retention is referred to as cutout in cotton (gossypium hirsutum l.). fruit load affects cutout, possibly through hormonal effects. experiments were conducted to test the hypothesis that fruits are a source of abscisic acid (aba) that moves into fruiting branches and growing points where it inhibits growth, flowering, and boll retention. removal of the flower or young boll at the first node of fruiting branches did not decrease the aba content of ... | 1985 | 16664000 |
| olfaction in the boll weevil,anthonomus grandis boh. (coleoptera: curculionidae): electroantennogram studies. | electroantennogram (eag) techniques were utilized to measure the antennal olfactory responsiveness of adult boll weevils,anthonomus grandis boh. (coleoptera: curculionidae), to 38 odorants, including both insect and host plant (gossypium hirsutum l.) volatiles. eags of both sexes were indicative of at least two receptor populations: one receptor population primarily responsive to pheromone components and related compounds, the other receptor population primarily responsive to plant odors. simila ... | 1984 | 24318432 |
| seed development in cotton: feasibility of a hormonal role for abscisic acid in controlling vivipary. | in maturing cotton (gossypium hirsutum l.) fruits, embryos acquire the capacity to germinate in vitro about 16 days before fruit maturity and dehiscence. vivipary is believed to be prevented by abscisic acid (aba) originating in the seed coat and diffusing to the embryo (the ihle-dure hypothesis). although endogenous aba levels are much greater in embryos than in seed coats during the period of germinability, in «donor-receiver» experiments movement of (14)c-aba is strongly polar in favor of the ... | 1984 | 23195715 |
| line x tester analysis for fixed effect model in cotton (gossypium hirsutum l.). | the data from an experiment in cotton consisting of three testers and 12 lines selected deliberately have been analysed. the investigation showed higher specific combining ability variance for yield of seed cotton and number of bolls, indicating the predominance of non-additive gene action. of parental lines, h777 was found to possess high g.c.a. effects for seed cotton yield, number of bolls and number of sympodes. parent h842 contributed only for boll weight, whereas h655 was good general comb ... | 1984 | 24257819 |
| stomatal responses to water stress and to abscisic acid in phosphorus-deficient cotton plants. | cotton (gossypium hirsutum l.) plants were grown in sand culture on nutrient solution containing adequate or growth-limiting levels of p. when water was withheld from the pots, stomata of the most recently expanded leaf closed at leaf water potentials of approximately -16 and -12 bars in the normal and p-deficient plants, respectively. pressure-volume curves showed that the stomata of p-deficient plants closed when there was still significant turgor in the leaf mesophyll. leaves of p-deficient p ... | 1984 | 16663851 |
| rhythmical changes in the sensitivity of cotton seedlings to herbicides. | cotton (gossypium hirsutum l.) seedlings that were grown under a photoperiod of 12 hours darkness and 12 hours light showed oscillations in their sensitivity to the herbicides sodium 5-(2-chloro-4-trifluoromethyl)-phenoxy)-2-nitrobenzoate (acifluorfen), butyl 2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoate (fluazifop) and 3-isopropyl-1h-2,1,3-benzothiadiazin-4(3h)-one 2,2-dioxide (bentazon). sensitivity was expressed in appearance of necrotic areas on the cotyledons and in decrease ... | 1984 | 16663835 |
| rhythmicity in ethylene production in cotton seedlings. | cotyledons of cotton (gossypium hirsutum l.) seedlings grown under a photoperiod of 12 hour darkness and 12 hour light showed daily oscillations in ethylene evolution. the rate of ethylene evolution began to increase toward the end of the dark period and reached a maximum rate during the first third of the light period, then it declined and remained low until shortly before the end of the dark period. the oscillations in ethylene evolution occurred in young, mature, and old cotyledons (7 to 21 d ... | 1984 | 16663650 |
| hydraulic conductance as a factor limiting leaf expansion of phosphorus-deficient cotton plants. | suboptimal levels of phosphorus (p) strongly inhibited leaf expansion in young cotton (gossypium hirsutum l.) plants during the daytime, but had little effect at night. the effect of p was primarily on cell expansion. compared to plants grown on high p, plants grown on low p had lower leaf water potentials and transpiration rates, and greater diurnal fluctuations in leaf water potential. hydraulic conductances of excised root systems and of intact transpiring plants were determined from curves r ... | 1984 | 16663629 |
| specific and direct measurement of theβ-1,3-glucan in developing cotton fiber. | the reaction of n,n-diethylaziridinium chloride with raw cotton (gossypium hirsutum l.) seed fibers to introduce n,n-diethylaminoethyl (deae) substituents at a low degree of substitution was used for demonstrating the presence of o(4)h, characteristic of a β-1,3-glucan. the derivatized 1,3-glucan/cellulose was hydrolyzed to deae-glucoses that were analyzed by gas-liquid chromatography. capillary columns proved effective for measuring the small amounts of 4-o-deae-glucose in the presence of major ... | 1984 | 24253657 |
| ontogeny of glyoxysomes in maturing and germinated cotton seeds-a morphometric analysis. | morphometric procedures were used with light and electron microscopy to examine glyoxysome number, volume, shape and distribution as well as mesophyll cell volume, in cotyledons of mature (50 d postanthesis), imbibed (5h) and germinated (24 and 37 h) cotton (gossypium hirsutum l.) seeds. additionally, activities of five glyoxysomal marker enzymes in cotyledon extracts were assayed at each of the above ages. cell volume was determined from photomicrographs of epon-embedded sections by the point-c ... | 1984 | 24253604 |
| transpiration-induced changes in the photosynthetic capacity of leaves. | high transpiration rates were found to affect the photosynthetic capacity of xanthium strumarium l. leaves in a manner analagous to that of low soil water potential. the effect was also looked for and found in gossypium hirsutum l., agathis robusta (c. moore ex muell.) bailey, eucalyptus microcarpa maiden, larrea divaricata cav., the wilty flacca tomato mutant (lycopersicon esculentum (l.) mill.) and scrophularia desertorum (munz) shaw. two methods were used to distinguish between effects on sto ... | 1984 | 24258416 |
| sugar uptake by cotton tissues: leaf disc versus cultured roots. | the tissue accumulation of sucrose, glucose, and fructose has been studied in cultured cotton (gossypium hirsutum l.) roots and leaf discs. sucrose uptake by both tissues from high apoplastic concentrations was independent of ph but has a slightly acidic ph optimum from low concentrations. like other higher plant tissues, cotton root cells accumulate sucrose via a ;saturable,' inhibitor-sensitive mechanism and a linear, inhibitor-resistant mechanism. the linear mechanism of sucrose uptake is not ... | 1984 | 16663371 |
| centromere orientation of quadrivalents of heterozygous translocations and an autoploid of gossypium hirsutum l. | cytological observations of quadrivalents of heterozygous translocations in gossypium hirsutum l. demonstrate that, in addition to alternate-1 and alternate-2 orientations, a third alternate orientation (alternate-3), which occurs as a three-dimensional, v-type configuration, can be identified.-two additional types of disjunctions, the centromere orientations of which are rotational modifications of either adjacent or alternate configurations, were also observed in quadrivalents of a translocati ... | 1983 | 17246172 |
| photosynthetic rate control in cotton : photorespiration. | the purpose of this research was to determine the magnitude of photorespiration in field-grown cotton (gossypium hirsutum l.) as a function of environmental and plant-related factors. photorespiration rates were estimated as the difference between measured gross and net photosynthetic rates.a linear increase in photorespiration was observed as air temperature increased from 22 to 40 degrees c at saturating photon flux density. at 22 degrees c, photorespiration was less than 15 per cent of net ph ... | 1983 | 16663278 |
| photosynthetic rate control in cotton : stomatal and nonstomatal factors. | the relationship between single leaf photosynthesis and conductance was examined in cotton (gossypium hirsutum l.) across a range of environmental conditions. the purpose of this research was to separate and define the degree of stomatal and nonstomatal limitations in the photosynthetic process of field-grown cotton.photosynthetic rates were related to leaf conductance of upper canopy leaves in a curvilinear manner. increases in leaf conductance of co(2) in excess of 0.3 to 0.4 mole per square m ... | 1983 | 16663277 |
| ultrastructural and chemical evidence that the cell wall of green cotton fiber is suberized. | green cotton (gossypium hirsutum l.) fibers were shown by electron microscopy to have numerous thin concentric rings around the lumen of the cell. these rings possessed a lamellar fine structure characteristic of suberin. lia1d(4) depolymerization and gas chromatography-mass spectrometry analysis showed the presence of a suberin polymer in the green cotton with the major aliphatic monomers being omega-hydroxydocosanoic acid (70%) and docosanedoic acid (25%). ordinary white cotton was shown by ch ... | 1983 | 16663251 |
| chloramphenicol stimulates acid phosphatase activity in germinating cotton (gossypium hirsutum) embryos. | low dosages of chloramphenicol (25-50 micrograms/ml) brought about a 2-4-fold stimulation of acid phosphatase activity in 48 h-germinated cotton (gossypium hirsutum) embryos. however, at high concentrations of chloramphenicol (100-1000 micrograms/ml), there was a progressive decline in enzyme activity. the stimulatory effect of the drug on acid phosphatase activity was relatively specific, since no significant stimulation of activities of proteinase, deoxyribonuclease, ribonuclease, o-diphenolas ... | 1983 | 6870857 |
| quantitation of chill-induced release of a tubulin-like factor and its prevention by abscisic acid in gossypium hirsutum l. | the degree of tubulin polymerization in cotton (gossypium hirsutum l. cv acala) cotyledonary tissue was estimated by radioimmunoassay which measured the amount of a tubulin-like factor. it was assumed that the release of this tubulin-like factor indicated depolymerization of microtubules. exposure to chilling resulted in complete release of the tubulin-like factor. pretreatment with abscisic acid in the light almost completely prevented the chill-induced release of the tubulin-like factor. addit ... | 1983 | 16662900 |
| intracellular distribution of free sugars in quiescent cottonseed. | quiescent cottonseeds (gossypium hirsutum l.) were fractionated non-aqueously to protein bodies and nonparticulate cytoplasm for analyses of sugar contents. nonparticulate cytoplasm was more than 3-fold richer in total free sugars than were protein bodies, but based on the content of cytoplasm in each fraction, sugars were distributed almost equally in them. thin-layer chromatography and high-pressure liquid chromatography revealed five sugars: sucrose, raffinose, tetrasaccharides i and ii, and ... | 1983 | 16662892 |
| metabolism of carbohydrate and lipid reserves in germinated cotton seeds. | utilization of reserve lipid and carbohydrates during germination (0-12 h) and postgerminative growth (12-48 h) was studied in cotton (gossypium hirsutum l.) seedlings. raffinose and stachyose were utilized during the germination period and early growth; mobilization was associated with α-galactosidase (ec 3.2.1.22) activity. results from pulse-chase experiments with [(3)h]raffinose supplied exogenously to 4-h soaked seeds indicated that raffinose-derived catabolites contributed to the coinciden ... | 1982 | 24272116 |
| kairomones and their use for management of entomophagous insects : xiii. kairomonal activity fortrichogramma spp. of abdominal tips, excretion, and a synthetic sex pheromone blend ofheliothis zea (boddie) moths. | volatile chemicals emanating from an excretion (apparently meconium) and abdominal tips of femaleheliothis zea (boddie) moths mediated increased rates of parasitization ofh. zea eggs bytrichogramma pretiosum riley. a blend of synthetic chemicals, consisting of hexadecanal, (z)-7-hexadecenal, (z)-9-hexadecenal, and (z)-11-hexadecenal, which has been identified as the sex pheromone of and from the abdominal tip of femaleh. zea moths, also increased rates of parasitization ofh. zea eggs byt. pretio ... | 1982 | 24414738 |
| water relations of cotton plants under nitrogen deficiency: v. environmental control of abscisic acid accumulation and stomatal sensitivity to abscisic acid. | suboptimal n nutrition increased the water potential for stomatal closure in water stressed cotton (gossypium hirsutum l.) leaves. this increased sensitivity to water stress had two components, increased accumulation of abscisic acid (aba) and increased apparent stomatal sensitivity to aba. low n increased the threshold water potentials for stomatal closure and aba accumulation by about 4 bars and 2 bars, respectively. low n also greatly increased stomatal response to low concentrations of exoge ... | 1982 | 16662614 |
| extraction and immunochemical assays of a tubulin-like factor in cotton seedlings. | antibodies to tubulin were prepared in rabbits by immunization with reduced-carboxymethylated calf-brain tubulin. in immunodiffusion tests the antibodies showed full cross reactivity with the immunogen as well as with native calf-brain tubulin. the same antibodies showed cross reactivity with a factor in extract of cotton (gossypium hirsutum l.) cotyledons but there was no full immunological identity between calf-brain tubulin and this factor. a solid-phase radioimmunoassay for quantitative esti ... | 1982 | 24276267 |
| effect of water stress on cotton leaves : i. an electron microscopic stereological study of the palisade cells. | palisade cells from fully expanded leaves from irrigated and nonirrigated, field grown cotton (gossypium hirsutum l. cv. paymaster 266) were subjected to a microscopic examination to evaluate the effect of water stress on subcellular structures. the water potential difference between the two treatments was 13 bars at the time of sampling. the dimensions of the palisade cells and their density per unit leaf area were determined by light microscopy. palisade cells from stressed plants had the same ... | 1982 | 16662453 |
| synthesis and movement of abscisic acid in water-stressed cotton leaves. | synthesis and movement of abscisic acid (aba) into the apoplast of water-stressed cotton (gossypium hirsutum l.) leaves were examined using pressure dehydration techniques. the exudates of leaves dehydrated in a pressure chamber contained aba. the level of aba in the exudates was insensitive to the leaf water potential when dehydration occurred over a 3-hour period. when leaves were rapidly dehydrated in the pressure chamber and held at a balance pressure coincident with the point of zero turgor ... | 1982 | 16662258 |
| fruit age and changes in abscisic acid content, ethylene production, and abscission rate of cotton fruits. | the relationships of fruit age, abscisic acid (aba) concentration, ethylene evolution, and abscission rates were studied in an effort to determine why cotton (gossypium hirsutum l., cv. deltapine 16) fruits rarely abscise more than 15 days after anthesis. because abscission of cotton fruits is increased by conditions that limit photosynthesis, greenhouse-grown plants with fruits of various ages were placed in dim light for 3 days to induce high rates of fruit abscission. abscission rates, aba co ... | 1982 | 16662207 |
| microtubules in differentiating sieve elements of gossypium hirsutum. | | 1982 | 7077737 |
| correction of flow resistances of plants measured from covered and exposed leaves. | the difference in water potential between an enclosed nontranspiring leaf and an adjacent exposed transpiring leaf, and the transpiration rate of a similarly exposed leaf, were used to calculate the change in hydraulic resistance of sorghum (sorghum bicolor [l.] moench) and sunflower (helianthus annuus l.) leaves throughout the day and at various rates of transpiration. since cotton (gossypium hirsutum l.) leaves enclosed in aluminum foil alone had enclosed leaf water potentials about 0.06 megap ... | 1981 | 16662056 |
| control of enzyme activities in cotton cotyledons during maturation and germination : iii. in-vitro embryo development in the presence of abscisic acid. | cotton (gossypium hirsutum l.) embryos excised from bolls 38-43 d after anthesis and cultured in vitro for 4 d on a nutrient agar medium containing 3.8 μm abscisic acid (aba) developed enzyme activity and accumulated insoluble protein, neutral lipid, and dry weight similar to embryos maturing on the plant. inclusion of aba in the medium prevented precosious germination and allowed continued increases in catalase, malate dehydrogenase, citrate synthase, aspartate aminotransferase, and β-oxidation ... | 1981 | 24301116 |
| stimulation of membrane-associated polysaccharide synthetases by a membrane potential in developing cotton fibers. | conditions which induce a transmembrane electrical potential, positive with respect to the inside of membrane vesicles, result in a substantial (4-12-fold) stimulation of the activity of membrane-associated β-glucan synthetases in a membrane preparation derived from the developing cotton (gossypium hirsutum l.) fiber. induction of electrical potentials which are negative with respect to the inside of the membrane vesicle results in little or no stimulation of β-glucan synthesis. those products w ... | 1981 | 24301030 |
| separation and measurement of direct and indirect effects of light on stomata. | conductance for water vapor, assimilation of co(2), and intercellular co(2) concentration of leaves of five species were determined at various irradiances and ambient co(2) concentrations. conductance and assimilation were then plotted as functions of irradiance and intercellular co(2) concentration. the slopes of these curves allowed us to estimate infinitesimal changes in conductance (and assimilation) that occurred when irradiance changed and intercellular co(2) concentration was constant, an ... | 1981 | 16661884 |
| ultrastructural studies of protophloem sieve elements in gossypium hirsutum. | | 1981 | 7277570 |
| nuclear degeneration and the association of endoplasmic reticulum with the nuclear envelope and microtubules in maturing sieve elements of gossypium hirsutum. | | 1981 | 7241642 |
| changes in the endoplasmic reticulum during differentiation of a sieve element in gossypium hirsutum. | | 1981 | 7241641 |
| correlation between chiasma frequency and quantitative traits in upland cotton (gossypium hirsutum l.). | four locally adapted and high yielding cultivars of upland cotton were examined in order to elucidate the relationship between total chiasma frequency and quantitative traits, including yield and fiber properties. total chiasma frequency per nucleus was found to correlate positively with boll number (r = 0.4041), seed cotton yield (r = 0.6003), seed index (r = 0.4624), lint yield (r = 0.7325), and lint index (r = 0.9534). the data are discussed from the point of view that the heterozygosity caus ... | 1980 | 24305760 |
| characterization of inhibitors of cellulose synthesis in cotton fibers. | several compounds were tested for their ability to inhibit the in-vivo synthesis of cellulose and other cell-wall polysaccharides in fibers of cotton (gossypium hirsutum l.) developing on in-vitro cultured ovules. inhibitory effects were measured by the ability of the compounds to inhibit the incorporation of radioactivity from [u-(14)c]glucose into these cell-wall polymers. of the compounds surveyed, 2,6-dichlorobenzonitrile (dcb) was the most effective and specific one for its effects on cellu ... | 1980 | 24310131 |
| prenyltransferase from gossypium hirsutum. | | 1980 | 7436426 |
| correlation between loss of turgor and accumulation of abscisic acid in detached leaves. | mature leaves of phaseolus vulgaris l. (red kidney bean), xanthium strumarium l. (cocklebur), and gossypium hirsutum l. (cotton) were used to study accumulation of abscisic acid (aba) during water stress. the water status of individual, detached leaves was monitored while the leaves slowly wilted, and samples were cut from the leaves as they lost water. the leaf sections were incubated at their respecitive water contents to allow aba to build up or not. at least 8 h were required for a new stead ... | 1980 | 24309706 |
| nutrient influences on leaf photosynthesis: effects of nitrogen, phosphorus, and potassium for gossypium hirsutum l. | the net rate of co(2) uptake for leaves of gossypium hirsutum l. was reduced when the plants were grown at low concentrations of no(3) (-), po(4) (2-), or k(+). the water vapor conductance was relatively constant for all nutrient levels, indicating little effect on stomatal response. although leaves under nutrient stress tended to be lower in chlorophyll and thinner, the ratio of mesophyll surface area to leaf area did not change appreciably. thus, the reduction in co(2) uptake rate at low nutri ... | 1980 | 16661231 |
| determination of the pore size of cell walls of living plant cells. | the limiting diameter of pores in the walls of living plant cells through which molecules can freely pass has been determined by a solute exclusion technique to be 35 to 38 angstroms for hair cells of raphanus sativus roots and fibers of gossypium hirsutum, 38 to 40 angstroms for cultured cells of acer pseudoplatanus, and 45 to 52 angstroms for isolated palisade parenchyma cells of the leaves of xanthium strumarium and commelina communis. these results indicate that molecules with diameters larg ... | 1979 | 17735052 |
| water relations of cotton plants under nitrogen deficiency: ii. environmental interactions on stomata. | nitrogen deficiency in cotton plants (gossypium hirsutum l.) considerably increased the sensitivity of stomata to water stress. at air temperatures of 27, 35, and >/=40 c, threshold potentials for complete stomatal closure were -10, -15, and -26 bars in n-deficient plants and -20, -20, and -30 bars in high-n plants, respectively. this three-way interaction among n supply, water potential, and air temperature was similar to that exerted on leaf expansion. the effects of n supply on stomatal behav ... | 1979 | 16660997 |
| water relations of cotton plants under nitrogen deficiency: i. dependence upon leaf structure. | cotton plants (gossypium hirsutum l.) grown on deficient levels of n exhibited many of the characteristics associated with drought resistance. in n-deficient plants, leaf areas and leaf epidermal cells were smaller than at the same nodes in high-n plants. n-deficient leaves lost only about half as much water per unit change in water potential as did high-n leaves. in addition, they maintained a greater relative water content than high-n leaves at any given potential. osmotic potentials (determin ... | 1979 | 16660996 |
| salinity effects on leaf anatomy: consequences for photosynthesis. | increasing salinity led to substantially higher ratios of mesophyll surface area to leaf area (a(mes)/a) for phaseolus vulgaris and gossypium hirsutum and a smaller increase for atriplex patula, a salt-tolerant species. the increase in internal surface for co(2) absorption did not lead to higher co(2) uptake rates, since the co(2) resistance expressed on the basis of mesophyll cell wall area (r(cell)) increased even more with salinity. the differences among species in the sensitivity of photosyn ... | 1979 | 16660795 |
| two light sources differentially affected ferric iron reduction and growth of cotton. | in growth chambers, low pressure sodium (lps) plus incandescent (inc) lamps and fluorescent cool-white (fcw) plus inc lamps were used to determine their effects on growth of cotton (gossypium hirsutum l.) and on the reduction of fe(3+) to fe(2+). cotton plants grown under lps + inc light developed chlorosis and grew poorly, whereas plants grown under fcw + inc lights were green. the chlorophyll concentration and top and root weights of cotton grown under lps + inc were lower than those under fcw ... | 1979 | 16660793 |
| nature and patterns of proteins during cotton seed development. | patterns of accumulation and ontogenetic relationships among proteins of cotton (gossypium hirsutum l.) seeds were examined between 10 days postanthesis and maturity (56 days). total and extractable nitrogen contents were determined; alkali- and water-soluble proteins were assayed quantitatively and electrophoretically. two alkali-soluble proteins present in the electrophoretogram of mature embryos first appeared at 21 days postanthesis; most of the final profile was established by 28 days. exce ... | 1979 | 16660708 |
| independent control of fiber development and nitrate reduction in cultured cotton ovules. | several lines of evidence implicate ammonium as an important factor in the growth and development of cotton (gossypium hirsutum l.) ovules cultured in vitro. for example, ovules cultured at 28 c require indoleacetic acid (iaa) and either ammonium or gibberellic acid (ga(3)) in the medium for fiber development, whereas ovules cultured at 34 c require only iaa. because of this effect of ammonium supply, it seemed possible that hormones or increased temperature were also promoting the availability ... | 1979 | 16660693 |
| movement of kinetin and gibberellic acid in leaf petioles during water stress-induced abscission in cotton. | movement of [(14)c]kinetin and [(14)c]gibberellic acid was examined in cotton (gossypium hirsutum l.) cotyledonary petiole sections independent of label uptake or exit from the tissue. sections 20 millimeters in length were taken from well watered, stressed, and poststressed plants. transport capacity was determined using a pulse-chase technique. movement of both kinetin and gibberellic acid was found to be nonpolar with a velocity of 1 millimeter per hour or less, suggesting passive diffusion. ... | 1979 | 16660670 |
| regulation of sugar uptake in hypocotyls of cotton. | uptake of sucrose and hexoses by hypocotyl segments of cotton (gossypium hirsutum l.) was shown to be dependent upon sugar level in the tissue. the effect was not related to total sugar level inasmuch as a portion of previously accumulated sugar was without influence on uptake. that portion was presumed to be compartmentalized, most likely in vacuoles. growth regulators modified the uptake pattern apparently through alterations in secondary metabolism. uptake and incorporation were inhibited by ... | 1978 | 16660624 |
| characteristics of sugar uptake in hypocotyls of cotton. | uptake of sucrose and hexoses by cotton (gossypium hirsutum l.) hypocotyl segments from free space was shown to be an active, carrier-mediated process. separate carriers existed for hexoses and sucrose. accumulated sugars appeared in both soluble and insoluble fractions of the tissue. at optimum temperature and ph, sucrose uptake rate versus concentration was fit by a rectangular hyperbola with v(max) of 14 micromoles per gram fresh weight per hour and k(m) of 8 mm. sucrose was the principal sug ... | 1978 | 16660623 |
| lipid and surface wax synthesis in water-stressed cotton leaves. | the incorporation of [2-(14)c]malonate and [1-(14)c]acetate into internal lipid and surface wax by cotton leaves (gossypium hirsutum l. ;deltapine') having water potentials of -8 to -15 bars (controls) and -19 to -32 bars (water-stressed) was compared. lipid from stressed leaves contained a mean of 57% more radioactivity than corresponding controls for five experiments. acetyl coenzyme a carboxylase was not limiting to fatty acid synthesis in water-stressed cotton leaves at the water potential l ... | 1978 | 16660581 |
| partitioning of sugar between growth and nitrate reduction in cotton roots. | the level of endogenous sugars was inversely related to nitrate availability in young cotton (gossypium hirsutum l.) plants, with high nitrate causing a greater decline in sugar content of roots than of shoots. high nitrate (low sugar) plants also displayed relatively more shoot growth and less root growth than low nitrate (high sugar) plants. these data are consistent with the theory that roots are poor competitors for sugar, and that sugar supply is a major factor limiting root growth in vivo. ... | 1978 | 16660556 |
| amino acid composition of germinating cotton seeds. | total and free amino acid composition of germinating cotton seeds (gossypium hirsutum l.) was determined. the germinating seeds were separated into cotyledon and developing axis fractions daily and the composition of each tissue was summed to get the whole seed composition. by separating the developing seeds into these two tissue fractions, and determining total and free amino acids, a balance sheet was developed for each amino acid. this technique allowed changes in distribution with time of ea ... | 1978 | 16660553 |
| control of enzyme activities in cotton cotyledons during maturation and germination: ii. glyoxysomal enzyme development in embryos. | the sequence of glyoxysomal enzyme development was investigated in cotyledons of cotton (gossypium hirsutum l. cv. deltapine 16) embryos from 16 to 70 days after anthesis (daa). catalase, malate dehydrogenase, and citrate condensing enzyme activities were barely detectable prior to 22 daa, but showed dramatic increases from 22 to 50 daa. development of malate synthase activity, however, was delayed during this period, rising to peak activity from 45 to 50 daa (just prior to desiccation) in the a ... | 1978 | 16660455 |
| on the resistance to transpiration of the sites of evaporation within the leaf. | the rates of transpiration from the upper and lower surfaces of leaves of gossypium hirsutum, xanthium strumarium, and zea mays were compared with the rates at which helium diffused across those leaves. there was no evidence for effects of co(2) concentration or rate of evaporation on the resistance to water loss from the evaporating surface ("resistance of the mesophyll wall to transpiration") and no evidence for any significant wall resistance in turgid tissues. the possible existence of a wal ... | 1978 | 16660404 |
| factors involved in in vitro stabilization of nitrate reductase from cotton (gossypium hirsutum l.) cotyledons. | experiments were conducted to determine if pretreatment of cotton (gossypium hirsutum l.) plants resulted in differential in vitro stabilities of nitrate reductase (nr) activity. although nr activity declines markedly during the second half of the daily light period, in vitro nr stability is not modified by time of harvest. phenylmethylsulfonylfluoride, iodoacetamide, and n-ethylmaleimide do not influence in vitro nr stability, suggesting that serine or sulfhydryl proteases are not responsible f ... | 1978 | 16660371 |
| the protein inclusions in sieve elements of cotton (gossypium hirsutum l.). | | 1978 | 209208 |
| developmental biochemistry of cotton seed embryogenesis and germination: x. nitrogen flow from arginine to asparagine in germination. | the enzymic basis for the flow of nitrogen from arginine to asparagine during the first 3 days of germination has been measured in extracts from cotton (gossypium hirsutum) cotyledons. evidence that asparagine synthetase regulates asparagine accumulation in germination (for transport to the axis) is presented. further, evidence that the bulk of the nitrogen passed from one generation to the next in dicots is through an asparagine cycle involving the following sequence asparagine --> arginine --> ... | 1978 | 16660366 |
| genetic lengths and break points in twelve chromosomes of gossypium hirsutum involved in ten reciprocal translocations. | chromosome configurations were recorded in about 5500 pollen mother cells (pmc's) in 2n and 2n-1 (missing the intact a-genome chromosome) heterozygotes of ten reciprocal translocations involving six a-genome chromosomes (h1, h2, h3, h4, h6 and h7) and six d-genome chromosomes (h14, h15, h16, h19, h20 and h21) of gossypium hirsutum. from these records, chiasma frequencies at each of six positions were determined for nine translocations and at two positions for one. these frequencies were used to ... | 1978 | 17248811 |
| evidence that the lipid carrier for n-acetylglucosamine is different from that for mannose in mung beans and cotton fibers. | cell-free enzyme particles from mung beans (phaseolus aureus) or cotton (gossypium hirsutum l.) fibers catalyze the incorporation of mannose from gdp-[(14)c]mannose and n-acetylglucosamine from udp-[(3)h]-n-acetylglucosamine into polyprenyl-type lipids. these lipids have been synthesized and purified and the lipid moieties compared to each other as well as to dolichyl phosphate and to lipids isolated from similar mannoseand n-acetylglucosamine-containing lipids from liver and aorta.the following ... | 1978 | 16660275 |
| hormonal regulation of cotton ovule and fiber growth: effects of bromodeoxyuridine, amo-1618 and p-chlorophenoxyisobutyric acid. | the effects of 5-bromo-2-deoxyuridine (budr, thymidine analogue), amo-1618 (2-isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine carboxylate methyl chloride), a growth retardant, and p-chlorophenoxyisobutyric acid (pcib, an antiauxin) on growth (dry weight increase) and fiber development in unfertilized cotton (gossypium hirsutum l.) ovules grown in vitro have been studied. budr (5 μm) causes about 70% inhibition of fiber production, with little effect on ovule growth, if applied during the f ... | 1978 | 24414871 |
| effect of hormones on nucleolar growth and vacuolation in elongating cotton fibers. | a rather precise combination of the three phytohormones, gibberellic acid, auxin, and abscisic acid, is necessary for the considerable growth of fiber nucleoli in gossypium hirsutum l. for about 8 days after anthesis and for nucleolar "vacuolation" in the second half of that period. nucleolar growth and vacuolation must occur in a precise sequence for the fiber to reach a good final length. nucleolar vacuolation indicates simultaneous output and neosynthesis of nucleolar material. | 1978 | 24414565 |
| phosphoenol-pyruvate-carboxylase activity in cotton and sorghum seeds and its relation to seedling development. | cotton (gossypium hirsutum) seeds and sorghum vulgare caryopses are able to incorporate co2 through a pep-carboxylating enzyme (ec 4.1.1.38). the enzyme activity is optimal at ph 8.2 and is unaffected by atp, gdp or acetyl coa. the partially purified cotton enzyme is stimulated by inorganic phosphate with an apparent km of 0.3 mm. the enzymes from both cultivars are inhibited by pyrophosphate, malate, and aspartate but not by succinate. kinetic studies for sorghum and cotton seed enzymes show ap ... | 1978 | 24414265 |
| influence of fusaric acid on circadian leaf movements of the cotton plant, gossypium hirsutum. | the cotton plant, gossypium hirsutum l. (cv. lakshmi) exhibits circadian leaf movements. fusaric acid (5-n butyl pyridine 2-carboxylic acid), an in vivo toxin shown to be produced during the pathogenesis of the wilt disease in cotton, causes phase shifts of the leaf movement rhythm that varied in degree and magnitude as a function of the treated phases. the data support the hypothesis that membranes play a vital role as a pacemaker in circadian rhythms. | 1978 | 24408653 |
| stomatal and nonstomatal regulation of water use in cotton, corn, and sorghum. | stomata of corn (zea mays l.) and sorghum (sorghum bicolor l.) responded to changes in leaf water potential during the vegetative growth phase. during reproductive growth, leaf resistances were minimal and stomata were no longer sensitive to bulk leaf water status even when leaf water potentials approached -27 bars. stomata of corn, cotton (gossypium hirsutum l.), and sorghum appear to respond to changes in the humidity deficit between the leaf and air and in this manner, regulated transpiration ... | 1977 | 16660199 |
| amino acid interactions in the regulation of nitrate reductase induction in cotton root tips. | glycine, asparagine, and glutamine inhibited the induction by nitrate of nitrate reductase activity in root tips of cotton (gossypium hirsutum l.). this inhibition was partially or entirely prevented when the inhibitor was applied in combination with any of several other amino acids. studies of (14)c-labeled amino acid uptake showed that, in most cases, the apparent antagonism resulted simply from competition for uptake. however, certain antagonists did not curtail uptake. the most effective of ... | 1977 | 16660116 |