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sts markers linked to the rf1 fertility restorer gene of cotton.marker-assisted selection (mas) can accelerate the process of plant breeding, and sequence-tagged site (sts) markers are highly specific for regions of dna being used for mas. the objective of this research was to develop sts markers tightly linked with rf1, the fertility restoring gene for cytoplasmic male sterility (cms) in cotton (gossypium hirsutum l.). bulked segregant analysis was employed to screen for rf1-linked rapd markers in a backcross population. four rapd markers were identified, t ...200515592810
[glyphosate-resistant cotton (gossypium hirsutum l.) transformed with aroam12 gene via agrobacterium tumefaciens].a mutant, aroam12, exhibiting resistance to glyphosate produced in a previous study using the staggered extension process with aroa genes from salmonella typhimurium and eschrichia coli. in this paper, we constructed a vector pgra1300 carrying aroam12 gene, comprising transit peptide of arabidopsis epsps, under the control of the camv35s promoter and used as selectable marker for cotton plant (gossypium hirsutum l.) transformation. transgenic cottons with increased resistance to glyphosate were ...200415599043
[cloning and characterization of two beta-mannosidase cdnas in gossypium hirsutum l].by using the method of pcr-based cdna library screening, two beta-mannosidase clones, ghmana1 and ghmana2, had been isolated. ghmana1 had a length of 2692 bp coding for a polypeptide of 834 amino acids, and ghmana2 was 3209 bp which encoded a polypeptide of 976 amino acids. ghmana1 and ghmana2 shared an identical sequence of 747 amino acids in their carboxyl-terminals, but were distinctly different in their amino-terminals. both beta-mannosidases were members of glycosyl hydrolase family 2, whic ...200415599050
chromosomal assignment of rflp linkage groups harboring important qtls on an intraspecific cotton (gossypium hirsutum l.) joinmap.chromosome identities were assigned to 15 linkage groups of the rflp joinmap developed from four intraspecific cotton (gossypium hirsutum l.) populations with different genetic backgrounds (acala, delta, and texas plains). the linkage groups were assigned to chromosomes by deficiency analysis of probes in the previously published joinmap, based on genomic dna from hypoaneuploid chromosome substitution lines. these findings were integrated with qtl identification for multiple fiber and yield trai ...201015618303
dexamethasone-inducible green fluorescent protein gene expression in transgenic plant cells.genomic research has made a large number of sequences of novel genes or expressed sequence tags available. to investigate functions of these genes, a system for conditional control of gene expression would be a useful tool. inducible transgene expression that uses green fluorescent protein gene (gfp) as a reporter gene has been investigated in transgenic cell lines of cotton (cot; gossypium hirsutum l.), fraser fir [fra; abies fraseri (pursh) poir], nordmann fir (nor; abies nordmanniana lk.), an ...200415629039
post-transcriptional gene silencing induced by short interfering rnas in cultured transgenic plant cells.short interfering rna (sirna) is widely used for studying post-transcriptional gene silencing and holds great promise as a tool for both identifying function of novel genes and validating drug targets. two sirna fragments (sirna-a and -b), which were designed against different specific areas of coding region of the same target green fluorescent protein (gfp) gene, were used to silence gfp expression in cultured gfp transgenic cells of rice (oryza sativa l.; os), cotton (gossypium hirsutum l.; gh ...200415629049
evaluation of transgenic cotton varieties and a glyphosate application on seedling disease incidence.a study was conducted to determine whether stand densities of transgenic cotton (gossypium hirsutum) varieties, with or without glyphosate, were similar to conventional varieties of the same lineage group in georgia and mississippi. transgenic and conventional cotton varieties were placed into five lineage groups of related varieties and seedling disease was evaluated in three greenhouse tests and a field trial using rhizoctonia solani ag-4. seed vigor was determined by standard germination stud ...200415645175
toxicity to cotton boll weevil anthonomus grandis of a trypsin inhibitor from chickpea seeds.cotton (gossypium hirsutum l.) is an important agricultural commodity, which is attacked by several pests such as the cotton boll weevil anthonomus grandis. adult a. grandis feed on fruits and leaf petioles, reducing drastically the crop production. the predominance of boll weevil digestive serine proteinases has motivated inhibitor screenings in order to discover new ones with the capability to reduce the digestion process. the present study describes a novel proteinase inhibitor from chickpea ...200515649779
confirmation and quantification of strigolactones, germination stimulants for root parasitic plants striga and orobanche, produced by cotton.the germination stimulants for root parasitic plants striga and orobanche produced by cotton (gossypium hirsutum l.) were examined in detail. seeds of cotton were germinated and grown on glass wool wetted with sterile distilled water in sterile filter units. the root exudate was collected daily and extracted with ethyl acetate. each of these ethyl acetate extracts was analyzed directly by high-performance liquid chromatography linked with tandem mass spectrometry (lc/ms/ms). the results demonstr ...200515665473
boll injury and yield losses in cotton associated with brown stink bug (heteroptera: pentatomidae) during flowering.brown stink bug, euschistus servus (say), was infested on cotton, gossypium hirsutum l., plants during reproductive stages to determine the effects on boll injury and seedcotton yield. during each week in 2002 and 2003, significantly more bolls with > or = 1 injured locule, bolls with > or = 2 injured locules, and bolls with discolored lint were recorded on stink bug-infested plants compared with that on noninfested plants. significantly fewer bolls displayed external injury on the boll exocarp ...200415666747
combined effects of elevated co2 and herbivore damage on alfalfa and cotton.we examined herbivore-induced responses of alfalfa (medicago sativa) and cotton (gossypium hirsutum) under different co2 conditions. plants were grown under ambient (350 ppm) or elevated (700 ppm) co2 levels, and were either damaged or undamaged by spodoptera littoralis larvae. at harvest, growth of undamaged (control) plants was determined, and foliar chemical composition of both undamaged and damaged plants was analyzed. cotton grew faster overall and showed a greater increase in growth in res ...200415672673
the delayed initiation and slow elongation of fuzz-like short fibre cells in relation to altered patterns of sucrose synthase expression and plasmodesmata gating in a lintless mutant of cotton.cotton (gossypium hirsutum l.) seed develops single-celled long fibres (lint) from the seed-coat epidermis at anthesis. previous studies have shown that the initiation and rapid elongation of these fibres requires the expression of sucrose synthase (sus) and, potentially, a transient closure of plasmodesmata. this study extends the previous work to examine the patterns of sus expression and plasmodesmata gating in fuzz-like short fibres of a mutant that shows delayed initiation and much slower a ...200515710635
[cloning and expression analysis of two rac genes from cotton (gossypium hirsutum l.)].plant rac proteins belong to an important group of signal switches anchoring on membranes, involved in various physiological processes including cell polar growth, synthesis of secondary wall, resistance response and hormone signaling. in the attempt to elucidate the molecular mechanism of initiation and elongation of cotton fiber, two cotton rac protein genes, designated as ghraca and ghracb, were amplified from elongating fibers and cloned. it was demonstrated that, the cdna of ghraca containe ...200515715441
the cotton actin1 gene is functionally expressed in fibers and participates in fiber elongation.single-celled cotton fiber (gossypium hirsutum) provides a unique experimental system to study cell elongation. to investigate the role of the actin cytoskeleton during fiber development, 15 g. hirsutum actin (ghact) cdna clones were characterized. rna gel blot and real-time rt-pcr analysis revealed that ghact genes are differentially expressed in different tissues and can be classified into four groups. one group, represented by ghact1, is expressed predominantly in fiber cells and was studied ...200515722467
resistance gene analogue markers are mapped to homeologous chromosomes in cultivated tetraploid cotton.degenerate primers designed from conserved motifs of known plant resistance gene products were used to amplify genomic dna sequences from the root-knot nematode (meloidogyne incognita) resistance genetic source, upland cotton (gossypium hirsutum) cultivar auburn 634 rnr. a total of 165 clones were isolated, and sequence analysis revealed 57 of the clones to be novel nucleotide sequences, many containing the resistance (r)-protein nucleotide-binding site motif. a cluster analysis was performed wi ...200515726317
validation of a cotton-specific gene, sad1, used as an endogenous reference gene in qualitative and real-time quantitative pcr detection of transgenic cottons.genetically modified (gm) cotton lines have been approved for commercialization and widely cultivated in many countries, especially in china. as a step towards the development of reliable qualitative and quantitative pcr methods for detecting gm cottons, we report here the validation of the cotton (gossypium hirsutum) endogenous reference control gene, sad1, using conventional and real-time (rt)-pcr methods. both methods were tested on 15 different g. hirsutum cultivars, and identical amplicons ...200515726375
transgenic cotton (gossypium hirsutum l.) seedlings expressing a tobacco glutathione s-transferase fail to provide improved stress tolerance.transgenic cotton (gossypium hirsutum l.) lines expressing the tobacco glutathione s-transferase (gst) nt107 were evaluated for tolerance to chilling, salinity, and herbicides, antioxidant enzyme activity, antioxidant compound levels, and lipid peroxidation. although transgenic seedlings exhibited ten-fold and five-fold higher gst activity under normal and salt-stress conditions, respectively, germinating seedlings did not show improved tolerance to salinity, chilling conditions, or herbicides. ...200515824906
antisense suppression of a (+)-delta-cadinene synthase gene in cotton prevents the induction of this defense response gene during bacterial blight infection but not its constitutive expression.in cotton (gossypium hirsutum) the enzyme (+)-delta-cadinene synthase (cdns) catalyzes the first committed step in the biosynthesis of cadinane-type sesquiterpenes, such as gossypol, that provide constitutive and inducible protection against pests and diseases. a cotton cdna clone encoding cdns (cdn1-c4) was isolated from developing embryos and functionally characterized. southern analysis showed that cdns genes belong to a large multigene family, of which five genomic clones were studied, inclu ...200515849309
systemic induction of volatile release in cotton: how specific is the signal to herbivory?plants attacked by herbivorous insects release chemical signals that attract natural enemies of the herbivores to the damaged plants. feeding of spodoptera exigua larvae on the lower leaves of cotton (gossypium hirsutum l.) for multiple feeding periods of 9-12 h with a 12 h, interval in between when the caterpillars are removed overnight, will induce a systemic release of volatile compounds that is comparable to the volatiles released in response to continuous feeding damage on the lower leaves ...200515856281
effects of potassium humate solution and soaking periods on germination characteristics of undelinted cotton seeds (gossypium hirsutum l.).the present study was conducted to determine the effects of soaking in potassium humate (ph) solution (55% humic acid, 30% fulvic acid and 8% potassium hydroxide) and distilled water (dw) for different periods (0, 4, 8 and 16 hours) on germination characteristics of undelinted seeds of cotton cv ersan-92. radicle, hypocotyl and seedling length, radicle and hypocotyl elongation rate and vigor index increased by ph solution treatment and increasing soaking periods. the medium x soaking period inte ...200415907066
successive chromosome walking by compatible ends ligation inverse pcr.here we describe an advanced polymerase chain reaction (pcr) technique, the compatible ends ligation inverse pcr (celi-pcr) for chromosome walking. in celi-pcr, several restriction enzymes, which produce compatible cohesive ends, were used to digest target dna simultaneously or sequentially to produce dna fragments of suitable size. dna fragments were then easily circularized and pcr amplification could be carried out efficiently. the previous limitations of inverse pcr were overcome, such as un ...200515920279
molecular cloning and characterization of a cotton glucuronosyltranferase gene.a glucuronosyltranferase gene has been isolated from cotton (gossypium hirsutum) fiber cells using rapid amplification of the cdna ends. the full-length cdna, designated ghglcat1, is 1400 bp in length (ay346330) and contains an open reading frame of 1107 bp encoding a protein of 368 amino acids. alignment of the ghglcat1 predicted amino acid sequence was shown to have high sequence similarity with animal glucuronosyltranferases. a phylogenic tree generated by the phylip program package showed th ...200515940874
evaluation of transgenic cotton varieties and a glyphosate application on seedling disease incidence.a study was conducted to determine whether stand densities of transgenic cotton (gossypium hirsutum) varieties, with or without glyphosate, were similar to conventional varieties of the same lineage group in georgia and mississippi. transgenic and conventional cotton varieties were placed into five lineage groups of related varieties and seedling disease was evaluated in three greenhouse tests and a field trial using rhizoctonia solani ag-4. seed vigor was determined by standard germination stud ...200515973787
okra-leaf accessions of the upland cotton (gossypium hirsutum l.): genetic variability in agronomic and fibre traits.okra-leaf types of the upland cotton have the potential to be competitive to the normal-leaf types in yield and fibre quality, in addition to its potential resistance to insect pests and drought. okra-leaf cotton accessions, collected at cotton research institute, faisalabad, pakistan, were evaluated in respect of genetic variance and relative performance in half- and full-sib crosses (combining ability) for 2 years. variation due to parents x years interaction was significant for lint percentag ...200515977325
molecular dissection of interspecific variation between gossypium hirsutum and gossypium barbadense (cotton) by a backcross-self approach: i. fiber elongation.the current study is the first installment of an effort to explore the secondary gene pool for the enhancement of upland cotton (gossypium hirsutum l.) germplasm. we developed advanced-generation backcross populations by first crossing g. hirsutum cv. tamcot 2111 and g. barbadense cv. pima s6, then independently backcrossing f(1) plants to the g. hirsutum parent for three cycles. genome-wide mapping revealed introgressed alleles at an average of 7.3% of loci in each bc(3)f(1) plant, collectively ...200515983756
molecular dissection of phenotypic variation between gossypium hirsutum and gossypium barbadense (cotton) by a backcross-self approach: iii. fiber length.a backcross-self population from a cross between gossypium hirsutum and g. barbadense was used to dissect the molecular basis of genetic variation governing 15 parameters that reflect fiber length. applying a detailed restriction fragment length polymorphism (rflp) map to 3,662 bc(3)f(2) plants from 24 independently derived bc(3) families, we detected 28, nine, and eight quantitative trait loci (qtls) for fiber length, length uniformity, and short fiber content, respectively. for eight, six, and ...200515983757
molecular dissection of interspecific variation between gossypium hirsutum and g. barbadense (cotton) by a backcross-self approach: ii. fiber fineness.a backcross-self population from a cross between gossypium hirsutum and g. barbadense was used to dissect the molecular basis of genetic variation governing two parameters reflecting lint fiber fineness and to compare the precision of these two measurements. by applying a detailed restriction fragment length polymorphism (rflp) map to 3,662 bc(3)f(2) plants from 24 independently derived bc(3) families, we were able to detect 32 and nine quantitative trait loci (qtls) for fiber fineness and micro ...200515995865
agricultural dust production in standard and conservation tillage systems in the san joaquin valley.the negative health effects of repeated dust exposure have been well documented. in california's san joaquin valley, agricultural operations may contribute substantially to airborne particulates. we evaluated four management systems to assess impacts on dust production and soil properties for a cotton (gossypium hirsutum l.)-tomato (lycopersicon esculentum mill.) rotation: standard tillage with (stcc) and without (stno) cover crop, and conservation tillage with (ctcc) and without (ctno) cover cr ...200615998847
functional characterization of gossypium hirsutum profilin 1 gene (ghpfn1) in tobacco suspension cells. characterization of in vivo functions of a cotton profilin gene.cotton fiber is an extremely long plant cell. fiber elongation is a complex process and the genes that are crucial for elongation are largely unknown. we previously cloned a cdna encoding an isoform of cotton profilin and found that the gene (designated ghpfn1) was preferentially expressed in cotton fibers. in the present study, we have further analyzed the expression pattern of ghpfn1 during fiber development and studied its cellular function using tobacco suspension cells as an experimental sy ...200516001260
size-dependent feeding and reproduction by boll weevil (coleoptera: curculionidae).the considerable variation in adult size of the boll weevil, anthonomus grandis grandis boheman, has been well documented, but the influences of adult size on reproductive rate are not known. we examined the relationship between the size of boll weevils and their feeding and oviposition. weevils weighed to the nearest milligram were grouped into five categories based on pupal weight: < or =5, 6-10, 11-15, 16-20, and >20 mg. numbers of lifetime punctures produced in flower buds (squares) of cotto ...200516022302
effects of planting dates on boll weevils (coleoptera: curculionidae) and cotton fruit in the subtropics.the effects of planting dates 2-3-wk apart on boll weevil, anthonomus grandis grandis boheman (coleoptera: curculionidae), field-level populations, and feeding and oviposition damage to cotton, gossypium hirsutum l., squares and bolls, were studied during 2002 and 2003 in the lower rio grande valley of texas. squares were 44-56% more abundant in some later planted treatments than in the earlier planted treatments, but mean cumulative numbers of oviposition- and feeding-damaged squares were 2.7 - ...200516022308
activity of selected neonicotinoids and dicrotophos on nontarget arthropods in cotton: implications in insect management.certain neonicotinoids are used in cotton, gossypium hirsutum (l.), to control various piercing-sucking pests. we conducted field studies using three neonicotinoids (acetamiprid, thiamethoxam, and imidacloprid) and an organophosphate (dicrotophos) to assess the activity of these insecticides against nontarget arthropods, particularly predators, and to determine the potential economic consequences of such activity. mortality among populations of the big-eyed bug, geocoris punctipes (say), and the ...200516022310
genetic mapping of a cross between gossypium hirsutum (cotton) and the hawaiian endemic, gossypium tomentosum.the existence of five tetraploid species that derive from a common polyploidization event about 1 million years ago makes gossypium (cotton) an attractive genus in which to study polyploid evolution and offers opportunities for crop improvement through introgression. to date, only crosses (hb) between the cultivated tetraploid cottons gossypium hirsutum and g. barbadense have been genetically mapped. genetic analysis of a cross (ht) between g. hirsutum and the hawaiian endemic g. tomentosum is r ...200516044266
occurrence of (+)- and (-)-gossypol in wild species of cotton and in gossypium hirsutum var. marie-galante (watt) hutchinson.gossypol occurs as a mixture of enantiomers in cottonseed. these enantiomers exhibit different biological activities. the (-)-enantiomer is toxic to animals, but it has potential medicinal uses. therefore, cottonseed with >95% (-)-gossypol could have biopharmaceutical applications. the (+)-enantiomer shows little, if any, toxicity to nonruminant animals. thus, cottonseed with >95% (+)-gossypol could be more readily utilized as a feed for nonruminants. the (+)- to (-)-gossypol ratio in commercial ...200516076104
ghhb1: a nonsymbiotic hemoglobin gene of cotton responsive to infection by verticillium dahliae.verticillium wilt of cotton is a widespread and destructive disease that is caused by the fungus pathogen verticillium dahliae. although no cotton cultivar is immune to the disease, some genotypes exhibit superior wilt tolerance. to gain an insight into the molecular mechanisms responsible for wilt tolerance, we employed the method of suppression subtractive hybridization (ssh) to isolate genes whose expression is up-regulated after inoculation of the pathogen in a wilt-tolerant cotton cultivar ...200516084605
isolation and characterization of drought-related trehalose 6-phosphate-synthase gene from cultivated cotton (gossypium hirsutum l.).due to the important role of cotton drought-tolerant varieties and the reported involvement in this trait of trehalose-6-phosphate-synthase, the respective gene (tps) was isolated and characterized from cultivated cotton, gossypium hirsutum (zeta 2 cultivar), using a chromosome-walking technique. tps has three exons comprising the coding region. southern blot analysis indicated that the gossypium genomes (a and d) contain a single copy of tps per genome. in addition, the expression of this gene ...200616086175
broiler litter as a micronutrient source for cotton: concentrations in plant parts.analytically, poultry litter contains nearly all essential micronutrients but the extent of phytoavailability of these nutrients and whether cotton (gossypium hirsutum l.) and other crop plants can receive adequate amounts of these nutrients from litter is not fully known. the objective of this research was to determine whether cotton receives sufficient amounts of fe, cu, mn, and zn from litter and estimate the efficiency of cotton in extracting these metal nutrients from litter in the absence ...200616091623
measuring gene flow in the cultivation of transgenic cotton (gossypium hirsutum l.).transgenic bt cotton newcott 33b and transgenic tfd a cotton tfd were chosen to evaluate pollen dispersal frequency and distance of transgenic cotton (gossypium hirsutum l.) in the huanghe valley cotton-producing zone, china. the objective was to evaluate the efficacy of biosafety procedures used to reduce pollen movement. a field test plot of transgenic cotton (6 x 6 m) was planted in the middle of a nontransgenic field measuring 210 x 210 m. the results indicated that the pollen of bt cotton o ...200516118411
a comparison of genetic maps constructed from haploid and bc1 mapping populations from the same crossing between gossypium hirsutum l. and gossypium barbadense l.simple sequence repeat (ssr) genetic maps have been separately constructed based on doubled haploid (dh) and (or) haploid and bc1 populations from the same cross between gossypium hirsutum l. 'tm-1' and gossypium barbadense l. 'hai7124'. the bc1 population was produced by pollinating individual plants of the 'tm-1' x 'hai7124' f1 with 'tm-1', whereas the dh and (or) haploid population developed from the offspring of vsg x ('tm-1' x 'hai7124'). vsg is a virescently marked semigamy line of gossypi ...200516121235
cleaved aflp (caflp), a modified amplified fragment length polymorphism analysis for cotton.in certain plant species including cotton (gossypium hirsutum l. or gossypium barbadense l.), the level of amplified fragment length polymorphism (aflp) is relatively low, limiting its utilization in the development of genome-wide linkage maps. we propose the use of frequent restriction enzymes in combination with aflp to cleave the aflp fragments, called cleaved aflp analysis (caflp). using four upland cotton genotypes (g. hirsutum) and three pima cotton (g. barbadense), we demonstrated that ca ...200516133304
characterization of a cdna encoding metallothionein 3 from cotton (gossypium hirsutum l.).a cdna encoding metallothionein (mt) was isolated from a library constructed with poly a(+) rna purified from 48 h etiolated cotton (gossypium hirsutum l.) cotyledons. this cdna encodes a deduced protein with 63 residues and a molecular weight of 6.3 kda. the protein has 10 cysteines of which 4 are within the cxxcxcxxxxxc amino-terminus motif and six are within the cxcxxxcxcxxcxc carboxyl-terminus motif characteristic of the type iii mt (mt3). the cotton mt3 protein sequence is 76.2, 69.8, 66.7, ...200516147860
estimating photosynthetic electron transport via chlorophyll fluorometry without photosystem ii light saturation.estimates of thylakoid electron transport rates (j(e)) from chlorophyll fluorometry are often used in combination with leaf gas exchange measurements to provide detailed information about photosynthetic activity of leaves in situ. estimating j(e) requires accurate determination of the quantum efficiency of photosystem ii (phi(p)), which in turn requires momentary light saturation of the photosystem ii light harvesting complex to induce the maximum fluorescence signal (f(m)'). in practice, full s ...200416151873
simple sequence repeat marker associated with a natural leaf defoliation trait in tetraploid cotton.cotton (gossypium hirsutum l.) leaf defoliation has a significant ecological and economical impact on cotton production. thus the utilization of a natural leaf defoliation trait, which exists in wild diploid cotton species, in the development of tetraploid cultivated cotton will not only be cost effective, but will also facilitate production of very high-grade fiber. the primary goal of our research was to tag loci associated with natural leaf defoliation using microsatellite markers in upland c ...201016159909
genetic mapping of new cotton fiber loci using est-derived microsatellites in an interspecific recombinant inbred line cotton population.there is an immediate need for a high-density genetic map of cotton anchored with fiber genes to facilitate marker-assisted selection (mas) for improved fiber traits. with this goal in mind, genetic mapping with a new set of microsatellite markers [comprising both simple (ssr) and complex (csr) sequence repeat markers] was performed on 183 recombinant inbred lines (rils) developed from the progeny of the interspecific cross gossypium hirsutum l. cv. tm1 x gossypium barbadense l. pima 3-79. micro ...200516187061
cycloheximide treatment of cotton ovules alters the abundance of specific classes of mrnas and generates novel ests for microarray expression profiling.fibres of cotton (gossypium hirsutum l.) are single elongated epidermal cells that start to develop on the outer surface of cotton ovules on the day of anthesis. little is known about the control of fibre initiation and development. as a first step towards discovering important genes involved in fibre initiation and development using a genomics approach, we report technical advances aimed at reducing redundancy and increasing coverage for anonymous cdna microarrays in this study. cotton ovule cd ...200516208490
cotton honeydew (gossypium hirsutum l.) extract offers very interesting properties for hair cosmetics and care products.cotton honeydew extract is composed of a unique combination of oligosaccharides, including fructose, glucose, inositol, melezitose, saccharose, trehalose and trehalulose. studies have shown that these oligosaccharides exhibit a protective effect. therefore, we were interested in studying the effect of these oligosaccharides on normal and damaged human hair. both clinical and scanning electron microscopy (sem) studies were performed. standardized human hair samples were used to determine the effe ...200516223202
leaf senescence-like characteristics contribute to cotton's premature photosynthetic decline.leaf and canopy photosynthesis of cotton (gossypium hirsutum l.) declines as the crop approaches cutout, just as the assimilate needs for reproductive growth are peaking. our objective with this study was to determine whether this decline is due to remobilization of leaf components to support the reproductive growth or due to some cue from the changing environmental conditions during the growing season. field studies were conducted in 1995-1996 at stoneville, mississippi, using six cotton genoty ...200016228485
[spontaneous and induced programmed cell death in suspension cell cultures of cotton (gossypium hirsutum l.)].cotton suspension cells grew well in the ms medium supplemented with 0.1 mg/l 2,4 d and 0.1 mg/l kt. senescence occurred when the cells were unsubcultured. the cells began to lose their viabilities on the 17th day, and on the 21th day oligonucleosomal sized dna fragments ( dna ladder) could be detected. oligonucleosomal sized dna fragments ( dna ladder) was the hallmark of the programmed cell death. programmed cell death of cotton suspension cells could be induced respectively by some stress fac ...200516231696
carbon source dependent somatic embryogenesis and plant regeneration in cotton, gossypium hirsutum l. cv. svpr2 through suspension cultures.highly reproducible and simple protocol for cotton somatic embryogenesis is described here by using different concentrations of maltose, glucose, sucrose and fructose. maltose (30 g/l) is the best carbon source for embryogenic callus induction and glucose (30 g/l) was suitable for induction, maturation of embryoids and plant regeneration. creamy white embryogenic calli of hypocotyl explants were formed on medium containing ms basal salts, myo-inositol (100 mg/l), thiamine hci (0.3 mg/l), piclora ...200516235728
developmental and gene expression analyses of a cotton naked seed mutant.cotton fiber development is a fundamental biological phenomenon, yet the molecular basis of fiber cell initiation is poorly understood. we examined molecular and cellular events of fiber cell development in the naked seed mutant (n1n1) and its isogenic line of cotton (gossypium hirsutum l. cv. texas marker-1, tm-1). the dominant mutation not only delayed the process of fiber cell formation and elongation but also reduced the total number of fiber cells, resulting in sparsely distributed short fi ...200616254724
selectivity of pesticides used on cotton (gossypium hirsutum) to trichogramma pretiosum reared on two laboratory-reared hosts.the side-effects of pesticides (insecticides, fungicides, herbicides and plant growth regulators) used on cotton were tested on adults and pupae of trichogramma pretiosum riley reared in the laboratory on two different hosts, the angoumois grain moth (sitotroga cerealella olivier) and the mediterranean flour moth (ephestia kuehniella (zeller)). the eggs of the host enclosing the parasitoid pupae received direct pesticide sprays, while the adults of the parasitoid were exposed to the pesticides t ...200616308868
structural determinants for plant annexin-membrane interactions.the interactions of two plant annexins, annexin 24(ca32) from capsicum annuum and annexin gh1 from gossypium hirsutum, with phospholipid membranes have been characterized using liposome-based assays and adsorption to monolayers. these two plant annexins show a preference for phosphatidylserine-containing membranes and display a membrane binding behavior with a half-maximum calcium concentration in the sub-millimolar range. surprisingly, the two plant annexins also display calcium-independent mem ...200516331990
characteristics, development and mapping of gossypium hirsutum derived est-ssrs in allotetraploid cotton.in order to construct a saturated genetic map and facilitate marker-assisted selection (mas) breeding, it is necessary to enhance the current reservoir of known molecular markers in gossypium. microsatellites or simple sequence repeats (ssrs) occur in expressed sequence tags (est) in plants. many ests are publicly available now and represent a good tool in developing est-ssrs. from 13,505 ests developed from our two cotton fiber/ovule cdna libraries constructed for upland cotton, 966 (7.15%) con ...200616341684
phyllosphere of cotton as a habitat for diazotrophic microorganisms.positive nitrogenase activities ranging from 0.18 to 0.78 nmol of c(2)h(4) cm h were detected on the leaf surfaces of different varieties of cotton (gossypium hirsutum l. and g. herbaceum l.) plants. beijerinckia sp. was observed to be the predominant nitrogen-fixing microorganism in the phyllosphere of these varieties. a higher level of phyllosphere nitrogen-fixing activity was recorded in the variety varalaxmi despite a low c/n ratio in the leaf leachates. leaf surfaces of the above variety po ...198416346639
identification and mapping of microsatellite markers linked to a root-knot nematode resistance gene (rkn1) in acala nemx cotton (gossypium hirsutum l.).host-plant resistance is the most economic and effective strategy for root-knot nematode (rkn) meloidogyne incognita control in cotton (gossypium hirsutum l.). molecular markers linked to resistance are important for incorporating resistance genes into elite cultivars. to screen for microsatellite markers (ssr) closely linked to rkn resistance in g. hirsutum cv. acala nemx, f1, f2, bc1f1, and f2:7 recombinant inbred lines (rils) from intraspecific crosses and an f2 from an interspecific cross wi ...200616362274
wide-cross whole-genome radiation hybrid mapping of the cotton (gossypium barbadense l.) genome.whole-genome radiation hybrid mapping has been applied extensively to human and certain animal species, but little to plants. we recently demonstrated an alternative mapping approach in cotton (gossypium hirsutum l.), based on segmentation by 5-krad gamma-irradiation and derivation of wide-cross whole-genome radiation hybrids (wwrhs). however, limitations observed at the 5-krad level suggested that higher doses might be advantageous. here, we describe the development of an improved second-genera ...200616362372
oviposition deterrents in larval frass of the cotton boll worm, helicoverpa armigera (lepidoptera: noctuidae): chemical identification and electroantennography analysis.oviposition deterrents in the frass of cotton bollworm (cbw), helicoverpa armigera larvae fed on an artificial diet (fa) and on cotton gossypium hirsutum leaves (fc) were investigated by behavioral bioassays and electroantennography analyses in the laboratory. it was found that a water suspension or a hexane extract of the frass fa or fc, in contrast to the corresponding foods, significantly deterred oviposition of conspecifics. when hexane extracts of the frass fa and fc were further partitione ...200616388821
the peroxidative coupling of hemigossypol to (+)- and (-)-gossypol in cottonseed extracts.peroxidase(s) present in embryo extracts of gossypium hirsutum cv. texas marker 1 catalyzed a bimolecular coupling of [4-(3)h]-hemigossypol to [4,4'-(3)h(2)]-gossypol. the reaction was dependent on the addition of h(2)o(2) and was inhibited 71-94% by 1 and 10mm sodium azide. the phenolic coupling produced 53% (+)-gossypol and 47% (-)-gossypol in close agreement to the 49% (+)-gossypol and 51% (-)-gossypol found in the intact seed. the nearly racemic mixture of (+)-and (-)-gossypol produced in th ...200616403543
isolation of a cotton reversibly glycosylated polypeptide (ghrgp1) promoter and its expression activity in transgenic tobacco.reversibly glycosylated polypeptides (rgps) are thought to be involved in polysaccharide metabolism. a cdna of the cotton (gossypium hirsutum) rgp gene, designated ghrgp1, has previously been characterized, and is preferentially expressed in fiber cells. in order to investigate its temporal and spatial control, we isolated a 624bp fragment upstream of the ghrgp1 coding sequence using a polymerase chain reaction (pcr)-based genomic walking method, transcriptionally fused the 624bp promoter sequen ...200616455356
function analysis of promoter trapping system after inserted into cotton (gossypium hirsutum l. ) genome.the technique of promoter trapping was developed to investigate its viability in cotton ( gossypium hirsutum l.) functional genomics. 141 independent transformants of cotton were generated via agrobacterium tumefaciens mediated transformation, of which 97% showed positive by pcr detection. the reporter, gus gene, was expressed to different extent in different organs, with a frequency of 48% in roots, 9.2% in vascular bundles of stem, 5.2% in leaves, and 51% in flowers. meanwhile, we discovered t ...200516459655
transcriptome profiling, molecular biological, and physiological studies reveal a major role for ethylene in cotton fiber cell elongation.upland cotton (gossypium hirsutum) produces the most widely used natural fibers, yet the regulatory mechanisms governing fiber cell elongation are not well understood. through sequencing of a cotton fiber cdna library and subsequent microarray analysis, we found that ethylene biosynthesis is one of the most significantly upregulated biochemical pathways during fiber elongation. the 1-aminocyclopropane-1-carboxylic acid oxidase1-3 (aco1-3) genes responsible for ethylene production were expressed ...200616461577
a global assembly of cotton ests.approximately 185,000 gossypium est sequences comprising >94,800,000 nucleotides were amassed from 30 cdna libraries constructed from a variety of tissues and organs under a range of conditions, including drought stress and pathogen challenges. these libraries were derived from allopolyploid cotton (gossypium hirsutum; a(t) and d(t) genomes) as well as its two diploid progenitors, gossypium arboreum (a genome) and gossypium raimondii (d genome). ests were assembled using the program for assembli ...200616478941
the gh3 family in plants: genome wide analysis in rice and evolutionary history based on est analysis.the gh3 gene family in arabidopsis, implicated in hormonal homeostasis through the conjugation of indolacetic and jasmonic acids to amino acids, is involved in a broad range of plant growth and development processes. in this work, the analysis of the gh3 family in the genome of oryza sativa identified 13 hypothetical orfs. est analysis and rt-pcr assays demonstrated that 12 of them were active genes. an extensive est analysis of the gh3 family performed on 26 plant species was used to estimate t ...200616488558
cotton genome mapping with new microsatellites from acala 'maxxa' bac-ends.fine mapping and positional cloning will eventually improve with the anchoring of additional markers derived from genomic clones such as bacs. from 2,603 new bac-end genomic sequences from gossypium hirsutum acala 'maxxa', 1,316 pcr primer pairs (designated as musb) were designed to flank microsatellite or simple sequence repeat motif sequences. most (1164 or 88%) musb primer pairs successfully amplified dna from three species of cotton with an average of three amplicons per marker and 365 marke ...200616501995
ratios of (+)- and (-)-gossypol in leaves, stems, and roots of selected accessions of gossypium hirsutum var. marie galante (watt) hutchinson.gossypol is an allelochemical that occurs naturally throughout the cotton plant as an enantiomeric mixture. gossypol and related terpenoids protect the plant from some insect herbivores. cottonseed has a high protein content, but it is underutilized because (-)-gossypol, which is toxic to nonruminants, occurs in the seed along with (+)-gossypol. commercial upland cottons usually have an approximate 3:2 (+)- to (-)-gossypol ratio in the seed, but plants can be bred with <8% (-)-gossypol using acc ...200616506812
proactive spraying against boll weevils (coleoptera: curculionidae) reduces insecticide applications and increases cotton yield and economic return.the current standard practice of two to three preemptive insecticide applications at the start of pinhead (1-2-mm-diameter) squaring followed by threshold-triggered (whenever 10% of randomly selected squares have oviposition punctures) insecticide applications for boll weevil, anthonomus grandis grandis boheman, control does not provide a reliably positive impact on cotton, gossypium hirsutum l., yields in subtropical conditions. this study showed that four fewer spray applications in a "proacti ...200516539122
physical mapping of the rf1 fertility-restoring gene to a 100 kb region in cotton.cytoplasmic male sterility (cms) plays an important role in crop heterosis exploitation. determining one or more nuclear genes that can restore male fertility to cms is essential for developing hybrid cultivars. genetic and physical mapping is the standard technique required for isolating these restoration genes. by screening 2,250 simple sequence repeat (ssr) primer pairs in cotton (gossypium hirsutum l.), we identified five new ssr markers that are closely linked to the rf1 gene, a fertility r ...200616544127
cloning and characterization of two erebp transcription factors from cotton (gossypium hirsutum l.).in this research, two erebp (ethylene response element binding protein) genes were isolated by the yeast one-hybrid system, named ghereb2 and ghereb3, and both have one intron in their coding regions. the deduced amino acid sequences of ghereb2 and ghereb3 have some typical features of transcription factors, one potential basic nuclear-localization signal, one possible acidic activation domain, and one conserved dna binding domain, and they show high similarity, especially in the dna-binding dom ...200616545065
the complete chloroplast genome sequence of gossypium hirsutum: organization and phylogenetic relationships to other angiosperms.cotton (gossypium hirsutum) is the most important fiber crop grown in 90 countries. in 2004-2005, us farmers planted 79% of the 5.7-million hectares of nuclear transgenic cotton. unfortunately, genetically modified cotton has the potential to hybridize with other cultivated and wild relatives, resulting in geographical restrictions to cultivation. however, chloroplast genetic engineering offers the possibility of containment because of maternal inheritance of transgenes. the complete chloroplast ...200616553962
complete assignment of the chromosomes of gossypium hirsutum l. by translocation and fluorescence in situ hybridization mapping.significant progress has been made in the construction of genetic maps in the tetraploid cotton gossypium hirsutum. however, six linkage groups (lgs) have still not been assigned to specific chromosomes, which is a hindrance for integrated genetic map construction. in the present research, specific bacterial artificial chromosome (bac) clones constructed in g. hirsutum acc. tm-1 for these six lgs were identified by screening the bac library using linkage group-specific simple-sequence repeats ma ...200616609860
metabolism of [14c]-2,4-dichlorophenol in edible plants.several 2,4-dichlorophenoxyacetic acid (2,4-d)-sensitive plants have been modified by genetic engineering with tfda gene to acquire 2,4-d tolerance. the expression product of this gene degrades 2,4-d to 2,4-dichlorophenol (dcp), which is less phytotoxic but could cause a problem of food safety. after a comparison of 2,4-d and dcp metabolism in transgenic 2,4-d-tolerant and wild cotton (gossypium hirsutum l.), a direct study of dcp metabolism in edible plants was performed. after petiolar uptake ...200616628540
comparative study on biological parameters of bemisia tabaci (genn.) collected on four host plants from varamin-iran.during 2003 biological parameters of sweetpotato whitefly, b. tabaci (genn.) (horn. aleyrodidae) as a major pest of field crops, vegetables and ornamentals were studied. in this study, the infested leaves of cucumber (cucumis sativus l.) zucchini (cucurbita pepo l.) eggplant (solanum melongena l.) and cotton (gossypium hirsutum l.) with whitefly nymphs and pupae were collected from varamin-iran, and were transferred to the laboratory. the newly emerged males and females of each population were r ...200516628901
diversity of boll weevil populations in south america: a phylogeographic approach.a phylogeographic approach was conducted to assess the geographic structure and genetic variation in populations of the boll weevil anthonomus grandis, which is the most harmful insect pest of cotton in the americas. coi and coii mitochondrial gene sequences were analyzed to test a former hypothesis on the origin of the boll weevil in argentina, brazil and paraguay, using samples from mexico and usa as putative source populations. the analysis of variability suggests that populations from south ...200616636929
spatial distribution of photosynthesis during drought in field-grown and acclimated and nonacclimated growth chamber-grown cotton.inhomogeneous photosynthetic activity has been reported to occur in drought-stressed leaves. in addition, it has been suggested that these water stress-induced nonuniformities in photosynthesis are caused by "patchy" stomatal closure and that the phenomenon may have created the illusion of a nonstomatal component to the inhibition of photosynthesis. because these earlier studies were performed with nonacclimated growth chamber-grown plants, we sought to determine whether such "patches" existed i ...199216652956
effects of cycling temperatures on fiber metabolism in cultured cotton ovules.the effects of temperature on rates of cellulose synthesis, respiration, and long-term glucose uptake were investigated using cultured cotton ovules (gossypium hirsutum l. cv acala sj1). ovules were cultured either at constant 34 degrees c or under cycling temperatures (12 h at 34 degrees c/12 h at 15-40 degrees c). rates of respiration and cellulose synthesis at various temperatures were determined on day 21 during the stage of secondary wall synthesis by feeding cultured ovules with [(14)c]glu ...199216653084
intact leaves exhibit a climacteric-like rise in ethylene production before abscission.the rate of ethylene production by intact, attached leaves of cotton plants (gossypium hirsutum l.) during aging and senescence was studied using a continuous flow system that allowed air around enclosed leaves to be scrubbed to collect and assay ethylene. senescence of lower leaves began around 150 d after planting in a controlled environment room. a progressive decline in the ethylene production rate was observed when comparing the 3rd, 6th, and 10th leaves from the base with each other. ethyl ...199216653164
effects of ethylene on auxin transport.the effect of ethylene on the uptake, distribution and polar transport of c(14) from indole-3-acetic acid-2-c(14) and naphthalene acetic acid-1-c(14) in tissue sections was studied. test species were cotton (gossypium hirsutum, l.) and cowpea (vigna sinensis, endl.). generally, incubation of tissue or intact plants with ethylene reduced the degree of polar auxin transport. ethylene inhibited the movement of both auxins in stem tissue and iaa in petiole tissue of cotton. the effect of ethylene on ...196616656230
rna composition in cotton.nucleotide compositions of soluble (srna), whole-cell, and in one instance particulate and nonparticulate, rna of embryos, cotyledons (dark and light-grown), leaves, stems, and roots of gossypium hirsutum were compared. evidence of substantial differences in the overall compositions of the rnas was not obtained. however, a tendency for some plant parts to differ, particularly in srna composition, and that of the cotyledons (including particulate and nonparticulate rna) to change during the forma ...196616656287
extraction of nucleic acids from lyophilized plant material.four methods for extracting nucleic acids from lyophilized cotton (gossypium hirsutum l. cv. stoneville 62) leaves and roots were compared. they were based on the use of: (i) hc10(4); (ii) koh; (iii) a mixture of 90% phenol, tris (hydroxymethyl) aminomethane buffer, and sodium lauryl sulfate; and (iv) nacl. (i) extracted large amounts of rna but little dna and extracted much carbohydrate and protein contaminants. (ii) gave a good yield of both rna and dna but extracted such large amounts of cont ...196616656306
effect of manganese toxicity on the indoleacetic acid oxidase system of cotton.the effect of substrate manganese on tissue manganese levels and activity of the indoleacetic acid (iaa)-oxidase system of cotton (gossypium hirsutum, l.) was investigated. a sand culture technique was used with 1, 3, 9, 27 and 81 mg manganese (mnso(4)) per liter nutrient solution applied in various experiments.the following relationships held for both long-term (126 days) and short-term (12-14 days) exposures to manganese treatment: a) there was a direct relationship between substrate and tissu ...196616656311
role of iaa-oxidase in abscission control in cotton.the potential role of indoleactic acid (iaa)-oxidase as an in vivo abscission regulating system in the cotton (gossypium hirsutum l.) cotyledonary explant was investigated. phenols (usually monophenols), which are cofactors of cotton iaa-oxidase in vitro, accelerated abscission. phenols (usually orthodihydroxyphenols), which inhibit cotton iaa-oxidase in vitro, inhibited abscission. inhibition or stimulation of abscission was accomplished by phenols both with and without iaa. results were simila ...196616656432
photosynthesis, transpiration, leaf temperature, and stomatal activity of cotton plants under varying water potentials.cotton plants, gossypium hirsutum l. were grown in a growth room under incident radiation levels of 65, 35, and 17 langleys per hour to determine the effects of vapor pressure deficits (vpd's) of 2, 9, and 17 mm hg at high soil water potential, and the effects of decreasing soil water potential and reirrigation on transpiration, leaf temperature, stomatal activity, photosynthesis, and respiration at a vpd of 9 mm hg.transpiration was positively correlated with radiation level, air vpd and soil w ...196716656488
characteristics of a virescent cotton mutant.the virescent cotton (gossypium hirsutum) mutant described here differs from normal cultivated cotton by a single mutation in the nucleus. the mutant exhibits nuclear control of chlorophyll and carotenoid development. young leaves are distinctly yellow and become green with age. there is no unusual photometabolism of (14)co(2) or (14)c-acetate in this mutant. it is probable that the nuclear virescent mutation is in a locus concerned with making structural units. the yellow leaves do show a high ...196816656945
oxidative and phosphorylative activities of mitochondria isolated from cotton hypocotyls.mitochondria isolated from 2 strains of cotton plant hypocotyls (gossypium hirsutum l. var. rex smooth leaf and rex glandless) were examined for their oxidative phosphorylation activities. bovine serum albumin at a relatively high concentration was essential in the extraction medium for the isolation of oxidatively active mitochondria from both strains of cotton. phosphorylation was obtained only with rex glandless cotton mitochondria. this activity was low in comparison to the mitochondria isol ...196816657001
stimulation of ethylene evolution and abscission in cotton by 2-chloroethanephosphonic acid.ethrel, a mixture of 2-chloroethanephosphonic acid and its ethyl ester, hastens abscission of leaves, debladed petioles, and flower buds of cotton plants (gossypium hirsutum, l.). both young and old leaves abscissed while still green. application of ethrel stimulated evolution of ethylene, and this response preceded abscission. air concentrations of ethylene around enclosed, treated-plants were adequate to produce abscission in plants. non-treated plants defoliated when enclosed with plants spra ...196916657066
abscission: role of cellulase.cellulase (beta-1,4-glucan-glucanohydrolase ec 3.2.1.4) activity increased during abscission and was localized in the cell separation layer of phaseolus vulgaris l. cv. red kidney (bean), gossypium hirsutum l. cv. acala 4-42 (cotton) and coleus blumei benth. princeton strain (coleus) abscission zone explants. cellulase activity was optimum at ph 7, was reduced by one-half after heating to 55 degrees for 10 min, and was associated with the soluble components of the cell. explants treated with agi ...196916657082
chilling injury and changes in adenosine triphosphate of cotton seedlings.young gossypium hirsutum l. seedlings chilled at 5 degrees showed a continual decrease in atp concentration with time of chilling. chilled plants returned to optimum conditions were able to restore the initial atp concentration when chilled only 1 day, but not when chilled 2 days. the decrease in atp with chilling was prevented by hardening the seedlings at 15 degrees for 2 days (14-hr-day-length) immediately before chilling. the atp level of hardened plants was higher than of unhardened plants. ...196916657107
abscission: role of abscisic acid.the effect of abscisic acid on cotton (gossypium hirsutum l. cv. acala 4-42) and bean (phaseolus vulgaris l. cv. red kidney) explants was 2-fold. it increased ethylene production from the explants, which was found to account for some of its ability to accelerate abscission. absci is acid also increased the activity of cellulase. increased synthesis of cellulase was not du to an increase in aging of the explants but rather was an effect of abscisic acid on the processes that lead to cellulase syn ...196916657181
ethylene modification of an auxin pulse in cotton stem sections.the effect of ethylene on the basipetal movement of indole-3-acetic acid-1-(14)c through cotton stem sections (gossypium hirsutum, l. var. stoneville 213) was studied apart from processes involved in the uptake and exit of auxin by the section. stem sections 60 mm in length were pretreated with ethylene or placed in room air (control) and pulse labeled for 20 min with iaa-1-(14)c. in both the ethylene treated and control sections, the iaa-1-(14)c taken up moved basipetally as a peak of radioacti ...196916657258
growth regulator changes in cotton associated with defoliation caused by verticillium albo-atrum.cotton plants, variety acala 4-42 family 77 (gossypium hirsutum l.,), were stem puncture-inoculated with either a defoliating isolate (t9) or a nondefoliating isolate (ss4) of verticillium albo-atrum (reinke and berth.). as symptoms developed, growth regulators were assayed in diseased plants to discern their importance in the disease syndrome.an avena coleoptile straight growth bioassay demonstrated the presence of several growth-regulatory compounds in cotton tissue extracts. indoleacetic acid ...197016657316
factors involved in the opening of the hypocotyl hook of cotton and beans.conditions influencing the opening of the bean (phaseolus vulgaris l.) and cotton (gossypium hirsutum l.) hypocotyl hook were defined. such hooks were shown to undergo geotropic curvature; orientation of the hook with respect to gravity greatly affected the observed opening. cotton and bean hooks behaved exactly opposite in regard to the presence of the cotyledons and apical bud. the cotton hook required the cotyledons for opening, but the corresponding tissue slowed or inhibited opening of the ...197016657340
effect of ethylene on the uptake, distribution, and metabolism of indoleacetic acid-1-c and -2-c and naphthaleneacetic acid-1-c.the effect of ethylene on the uptake, distribution, and metabolism of indoleacetic acid (iaa)-1-(14)c, iaa-2-(14)c, and naphthaleneacetic acid (naa)-1-(14)c in cotton stem sections (gossypium hirsutum l., var. stoneville 213) was studied. stem sections excised from plants pretreated with ethylene for 15 hours transported significantly less (14)c-iaa and (14)c-naa than control sections. concomitant features of the reduction of (14)c-iaa transport were an increase in decarboxylation and a trend to ...197016657409
stimulation of solute loss from radicles of gossypium hirsutum l. by chilling, anaerobiosis, and low ph.the loss of organic substances from cotton (gossypium hirsutum l.) radicles is enhanced by chilling, low ph, or anaerobic conditions. solute loss returns to a low level when the stimulus is removed, indicating no permanent injury to membranes. loss of solute induced by chilling or anaerobiosis is reversed or prevented by calcium or magnesium. these cations did not reduce the solute loss resulting from low ph. the site of loss appears to be localized at or near the root tip. if the seedling cotyl ...197016657421
identification and quantitative analysis of the volatile substances emitted by maturing cotton in the field.when atmosphere from cotton plants (gossypium hirsutum l., var. deltapine smoothleaf) was condensed by passing it over the expansion coil of an air conditioner and three 1-hour collections per day (early morning, noon, and late afternoon) were made, the total essential oils were found to consist of 50 to 60% beta-bisabolol (i(k) 1660) and gamma-bisabolene (i(k) 1550) and 30 to 40% geraniol (i(k) 1250), myrtenal (i(k) 1328), nerolidol (i(k) 1520), and beta-caryophyllene oxide (i(k) 1590). as the ...197116657733
chilling injury and nucleotide changes in young cotton plants.the effects of chilling at 3 to 5 c on the nucleotide composition of roots and leaves of cotton (gossypium hirsutum l.) seedlings were determined. chilling decreased the concentration of nucleotides, especially di- and triphosphates, in both leaves and roots. chilling also caused an increase in free nucleosides. the results are interpreted to mean that general phosphorolytic activity is associated with chilling injury rather than damage to the phosphorylating mechanisms alone. hardening at 10 to ...197116657756
abscission: the role of ethylene modification of auxin transport.the role of ethylene-mediated reduction of auxin transport in natural and ethylene-induced leaf abscission was studied in the cotton (gossypium hirsutum l., cv. stoneville 213) cotyledonary leaf system. the threshold level of ethylene required to cause abscission of intact leaves was between 0.08 and 1 mul/l with abscission generally occurring 12 to 24 hours following ethylene fumigation. the threshold level of ethylene required to reduce the auxin transport capacity in the cotyle-donary petiole ...197116657764
influence of soil water stress on evaporation, root absorption, and internal water status of cotton.diurnal variations in leaf water potential, diffusion resistance, relative water content, stem diameter, leaf temperature, and energy balance components were measured in cotton (gossypium hirsutum l. var. lankart 57) during drought stress under field conditions. a plot of leaf water potential against either relative water content or stem diameter during the 24-hour period yielded a closed hysteresis loop. the relation between cell hydration and evaporation is discussed.despite low soil water pot ...197116657880
malate dehydrogenase isoenzymes from cotton leaves: molecular weights.malate dehydrogenase isolated from leaves of the cotton plant (gossypium hirsutum l.) appears in the form of several isoenzymes. four of the isoenzymes found in cotton leaf extracts appear to be charge isomers with a molecular weight of approximately 60,000. a fifth malate dehydrogenase isoenzyme found in leaf extracts has a molecular weight of approximately 500,000. under appropriate conditions it is possible to form this high molecular weight isoenzyme from at least one of the smaller isoenzym ...197216657908
the influence of low substrate sodium levels upon the free amino acid content of cotton leaves.the sodium nutrition of cotton (gossypium hirsutum l.) was investigated. plants were grown in purified nutrient solutions within a chamber designed to minimize sodium contamination. three nutrient solutions were employed that contained in microequivalents/liter: (a) 0.17 na, (b) 43.5 na and (c) 0.75 cs, 14.41 li, and 1.17 rb. all solutions had adequate potassium. total free amino acids were increased by sodium. leaves from plants grown in the high sodium solution contained significantly more fre ...197216657991
the relationship of the peroxidative indoleacetic acid oxidase system to in vivo ethylene synthesis in cotton.since peroxidase and manganese have been implicated in both auxin destruction and ethylene production, the effect of auxins and high tissue levels of manganese on the peroxidative indoleacetic acid oxidase system and the internal level of ethylene was determined in cotton (gossypium hirsutum l. cv. watson gl-7). the highest level of manganese tested produced manganese toxicity symptoms, including necrotic lesions, accompanied by an increase in internal ethylene levels at about 15 days after trea ...197216658000
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