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Following the discovery of aflatoxin M in cow's milk in the previous study, the contamination with aflatoxin of cotton-seed and cotton-seed cake which constitute the principal feed of local animals was measured. The samples were taken from 2 factories. The grain from the 1st factory was grown in the centre of the country in dry climate, and those from the 2nd source originated from the humid region of the north of Iran. The grain and cotton-seed cake from the 1st factory did not contain aflatoxin before storage. During storage the sample contamination amount and percent increased with time in both regions, with the dry less than the humid. In conclusion, Iranian cotton-seed and cotton-seed cake appear to be contaminated with aflatoxin B in 2 processes. The 1st is aflatoxin contamination before harvest, in the humid region of Iran; the 2nd is general storage aflatoxin contamination in both regions in which humidity and length of storage appear to be the principal factors.
Bacterial contamination of various parts of the cotton plant and of cotton from different mills was investigated. The predominant bacterial species were Gram-negative rods mainly of the Enterobacter genus. When guinea pigs inhaled strains of these bacteria cultivated from cotton, a strong leucocyte mobilising capacity was found for Pseudomonas and Enterobacter but not for Agrobacterium or Bacillus species. The aetiology of the development of pulmonary symptoms after inhalation of bacteria-containing dusts and subsequent production of endotoxins is discussed.
This paper introduces the long-term and continuing studies of the authors and their colleagues on several aspects of the host-parasite relations in cotton rat filariasis. Five methods are described for the calculation of the number of infective larvae of Litomosoides carinii transmitted to cotton rats and other laboratory animals by groups of Liponyssus bacoti mites. The relation between the calculated transmission intensities and the number of worms recovered from individual infected animals has been determined by each of the five methods. The accuracy and relevance of each method is discussed and one (method B) has been found to give a better correlation with worm recovery than the others. Some effects of infection with filariasis on the mites are described. The role of heavily infected mites in transmission is questioned and their influence on the calculation of transmission is discussed.
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The objective of this study was to determine the specific botanical ingredients present in respirable raw cotton dust. Significant differences in content of gross leaflike (bractcontaining) trash were found between several grade divisions of raw cottons. For example, higher grades of raw cotton (strict low middling = SLM) contained less leaflike trash than lower grade cottons (low middling = LM). The potential for production of fine particulate from botanical trash materials plus lint and linters was determined in the laboratory by an abrasive milling test. Bract and wood fragments were the most friable of all plant materials found in raw cottons whereas seed meat, lint, linters and seed coat were the least friable. Respirable (10 less than 10 micrometers) raw cotton dusts associated with the processing of middling, SLM and LM raw cottons were predicted to contain the following % weight composition of specific vegetable ingredients: leaflike = 70--72%, stem = 13--18%, bark = 3--8%, exocarp-mesocarp = 3.6%, endocarp = 1--2% and seed = 0.5--2%. Bract is the most abundant component in respirable raw cotton dust.
Compared with other transcription factors, much less studies have been performed on paclobutrazol-resistance (PRE), a subgroup of the extensive bHLH transcription factor gene family, and the research in cotton was also limited. By utilizing the PRE genes and their conserved domains identified in Arabidopsis, a total of 23, 22, 11, and 12 PRE genes were identified from two major cultivated cotton species and their two ancestors, respectively. The cotton PRE gene family was categorized into three subgroups based on evolutionary tree analysis. Motif and intron analyses indicated that the PRE gene has remained highly conserved throughout evolution. Collinearity analysis indicated that gene duplication, particularly through fragment replication, has significantly contributed to the expansion of the cotton PRE family. An exploration of the conserved elements within the PRE gene family uncovered numerous elements associated with plant stress resistance. Additionally, cotton transcriptome and qRT-PCR analysis showed that PRE genes were associated with a variety of abiotic stresses, including salt, drought, and cold treatments. Subcellular localization experiments indicated that the GhPRE3 gene is associated with membrane proteins. Finally, we selected the GhPRE3 gene for a VIGS experiment, which revealed that under salt stress and drought stress conditions, the wilting of leaves in the GhPRE3-silenced plants was significantly more severe than that observed in the control group, with T-AOC levels notably lower and MDA levels significantly higher. Overexpression of GhPRE3 enhanced seed germination and root development in transgenic Arabidopsis thaliana under salt stress and drought stresses. This suggests that GhPRE3 plays a positive regulatory role in cotton tolerance to salt and drought stressed, providing a reference for molecular genetic breeding of cotton with salt and drought tolerance.
Root cell fate and patterning in plants are orchestrated by the expression of cell-type-specific genes, including WEREWOLF (WER). Phylogenetic analysis of WER, functional WER homologs in Type III species (Rhodiola rosea and Boehmeria nivea), and related R2R3 MYB proteins identified in the cotton genome revealed that GhMYB109-a known regulator of fiber development in cotton ovules-clustered in a clade with Arabidopsis thaliana WER. To determine whether GhMYB109 is a functional homolog of WER, we expressed GhMYB109 under the control of the CaMV 35S promoter in the Arabidopsis thaliana wer-1 mutant and analyzed root epidermal cell patterning by counting root hairs. GhMYB109 expression significantly decreased the percentage of root hairs at both H and N positions. We found that most epidermal cells in the cotton root develop into root hairs (Type I pattern) although the cotton genome contains a functional WER homolog, GhMYB109. Additionally, GhMYB109 has been reported not to be expressed in cotton roots. These support the idea that GhMYB109 is a functional homolog of WER and that Arabidopsis thaliana and cotton diverged in root epidermal morphology through modifications in cis-regulatory elements rather than a functional divergence of their WER-like R2R3 MYB transcription factors.
Raw cotton from 4 machine picked varieties and 2 machine stripped varieties is examined by stereomicroscope and bright-field microscopy for presence of plant trash(bract, leaf, stem, seed, boll, and weed fragments-size range 841-2000mum) that gives rise to cotton dust during yarn manufacturing operations. Bract was found to be the major trash component in all raw cottons examined. Cotton leaf and non-cotton weed materials were also major trash components in most raw cottons.
A technique employing a fluorescent tracer for following the break-up and dispersion of cotton trash has been developed. Senescent cotton leaves were treated with a fluorescent dye, pulverized to match the same particle size distribution as naturally occurring leaf in raw seed cotton and uniformly incorporated into the seed cotton mass prior to processing in a saw-type micro-gin. A control lot was similarly processed, excluding any dye. Airborne samples collected from the major fugitive dust emission points by standard techniques, macro trash samples collected from four locations, and the final condensed lint product clearly show that the use of such tracers is not only feasible but highly useful in determining the locations where respirable dust is emitted. From the fraction of labelled tracer material found at any site, the relative amounts of both total and respirable dust emissions of that plant component can be estimated from the known masses of dyed material added to a given mass of seed cotton. Estimates of the relative severity of fugitive dust emissions from various processing steps in a cotton gin are presented based on vertical elutriator, high volume and multistage cascade impactor sampler data.
BACKGROUND: Hybrid breakdown has been well documented in various species. Relationships between genomic heterozygosity and traits-fitness have been extensively explored especially in the natural populations. But correlations between genomic heterozygosity and vegetative and reproductive traits in cotton interspecific populations have not been studied. In the current study, two reciprocal F2 populations were developed using Gossypium hirsutum cv. Emian 22 and G. barbadense acc. 3-79 as parents to study hybrid breakdown in cotton. A total of 125 simple sequence repeat (SSR) markers were used to genotype the two F2 interspecific populations. RESULTS: To guarantee mutual independence among the genotyped markers, the 125 SSR markers were checked by the linkage disequilibrium analysis. To our knowledge, this is a novel approach to evaluate the individual genomic heterozygosity. After marker checking, 83 common loci were used to assess the extent of genomic heterozygosity. Hybrid breakdown was found extensively in the two interspecific F2 populations particularly on the reproductive traits because of the infertility and the bare seeds. And then, the relationships between the genomic heterozygosity and the vegetative reproductive traits were investigated. The only relationships between hybrid breakdown and heterozygosity were observed in the (Emian22 × 3-79) F2 population for seed index (SI) and boll number per plant (BN). The maternal cytoplasmic environment may have a significant effect on genomic heterozygosity and on correlations between heterozygosity and reproductive traits. CONCLUSIONS: A novel approach was used to evaluate genomic heterozygosity in cotton; and hybrid breakdown was observed in reproductive traits in cotton. These findings may offer new insight into hybrid breakdown in allotetraploid cotton interspecific hybrids, and may be useful for the development of interspecific hybrids for cotton genetic improvement.
Modern cultivated cotton fibers are predominantly white with enhanced quality compared to their wild ancestors. However, the molecular mechanisms and evolutionary drivers linking fiber color to quality remain least focused. In this study, we identified FQC1 (Fiber Quality and Color 1), a major quantitative trait locus (QTL) on chromosome A07 that concurrently regulates both fiber quality and pigmentation. Through map-based cloning, we revealed that Gossypium hirsutum TRANSPARENT TESTA2-A07 (GhTT2-A07), an R2R3-MYB transcription factor, resides within this locus. GhTT2-A07 modulates fiber development by directly activating genes in the general phenylpropanoid pathway, thereby promoting the metabolic flux toward downstream secondary metabolites. Variations in the GhTT2-A07 promoter led to its reduced expression in modern white cotton cultivars. This down-regulation suppresses the accumulation of S/G/H-type lignin monomers and proanthocyanidins, resulting in altered secondary cell wall composition and ultimately enhancing the quality of mature white fibers. Population genetic analyses further indicate that the white-fiber allele GhTT2-A07W has been fixed in modern breeding genotypes, underscoring the impact of artificial selection during cotton domestication. Overall, our study elucidates the biochemical and molecular mechanisms underlying fiber quality and pigmentation in cotton, clarifies the selection criteria for high-quality white fibers in modern cultivars, and provides a theoretical basis for future targeted genetic improvement of cotton fibers.
This study provides a comprehensive analysis of the impact of DNA methylation in cotton under salt stress conditions, elucidating its effects on gene expression and biological processes. Here, we determined the structures of the DNA methylation landscape across the cotton genome subjected to salt stress using whole-genome bisulfite sequencing (WGBS) and RNA-seq methodologies. We identified 4938 differentially methylated regions (DMRs) correlated with alterations in gene expression. Salt stress induced significant shifts in DNA methylation patterns, particularly in CHH contexts, suggesting context-dependent epigenetic regulation. DMRs were found to be implicated in diverse biological processes and pathways, encompassing protein metabolism, cellular homeostasis, starch and sucrose metabolism, and plant hormone signaling, all pivotal for cotton's adaptation to salt stress. Furthermore, RNA-seq analysis confirmed the impact of DNA methylation on gene expression, uncovering 9642 salt stress-responsive differentially expressed genes (DEGs). These DEGs exhibited enrichment in pathways such as carbohydrate metabolism, cell wall synthesis, and defense response, underscoring the intricate interplay between methylation and gene regulation in stress response. Moreover, the study investigated the role of the key DNA methyltransferase gene GhDMT7 in modulating cotton's response to salt stress, revealing that its downregulation enhanced cotton's salt tolerance, potentially attributed to decreased DNA methylation levels, reduced membrane damage, and enhanced antioxidant capacity. These findings elucidate the role of DNA methylation in abiotic stress resilience and provide insights for crop improvement.
Cotton dust particle distribution in respiratory airways was measured to determine if specific size particles of the heterogeneous dust are concentrated as a function of airway diameter. Previously reported work indicated that the fine particles are responsible for the decrement in pulmonary function which occurs subsequent to cotton dust inhalation. After recovery, particles were sized and counted microscopically. Significant increases in fine particles (5-7 mu) were found in all airways of exposed animals as compared with controls. These particles become more concentrated as the airway diameter decreased. Histamine determinations were made in mice lungs after the animals were exposed to cotton dust for various periods of time to see if such treatment could be correlated with elevations in the concentrations of this biogenic amine. Lung histamine increased as exposure time to cotton dust increased. It is concluded that the lung histamine release occurring after cotton dust inhalation is related to some property of the fine particles of the heterogeneous dust.
The cotton rat (Sigmodon) is the gold standard pre-clinical small animal model for respiratory viral pathogens, especially for respiratory syncytial virus (RSV). However, without a reference genome or a published transcriptome, studies requiring gene expression analysis in cotton rats are severely limited. The aims of this study were to generate a comprehensive transcriptome from multiple tissues of two species of cotton rats that are commonly used as animal models (Sigmodon fulviventer and Sigmodon hispidus), and to compare and contrast gene expression changes and immune responses to RSV infection between the two species. Transcriptomes were assembled from lung, spleen, kidney, heart, and intestines for each species with a contig N50 > 1600. Annotation of contigs generated nearly 120,000 gene annotations for each species. The transcriptomes of S. fulviventer and S. hispidus were then used to assess immune response to RSV infection. We identified 238 unique genes that are significantly differentially expressed, including several genes implicated in RSV infection (e.g., Mx2, I27L2, LY6E, Viperin, Keratin 6A, ISG15, CXCL10, CXCL11, IRF9) as well as novel genes that have not previously described in RSV research (LG3BP, SYWC, ABEC1, IIGP1, CREB1). This study presents two comprehensive transcriptome references as resources for future gene expression analysis studies in the cotton rat model, as well as provides gene sequences for mechanistic characterization of molecular pathways. Overall, our results provide generalizable insights into the effect of host genetics on host-virus interactions, as well as identify new host therapeutic targets for RSV treatment and prevention.
Cotton production in the US faces a serious threat from Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4), a soil-borne fungus causing Fusarium wilt by infecting the roots and vascular system of susceptible cotton, leading to rapid wilting and death. Here, we investigate genetic mechanisms of resistance to FOV4 in the highly resistant upland cotton genotype "U1" using an early-generation segregating biparental population ("U1" × "CSX8308") with comprehensive genomic resources. Reference-grade genomic assemblies of the parents revealed minor structural variations between "U1" haplotypes, a high degree of collinearity at chromosome synteny and micro-synteny levels, and significant divergence from "CSX8308" with 8.9 million SNPs. QTL analysis identified significant markers on chromosomes D03 and A02 linked to reduced Fusarium wilt severity. Within these regions, two glutamate-receptor-like (GLR) genes showed structural variation and overlapped between translocated segments on A02 and D03, suggesting a rare but important reinforcing effect of parallel evolution between susceptible and resistant genotypes. Transcriptome profiles of "U1" under FOV4 infection reveal activation of calcium-binding proteins and transcription factors regulating plant hormones (ethylene, abscisic acid, jasmonic acid, and salicylic acid), along with enzymes involved in cell wall remodeling and phytoalexin production. Advancing cotton improvement depends on incorporating durable genetic disease resistance into high-yielding, high-quality cultivars.
The influence of the bacterial contamination of cotton dust on the development of pulmonary symptoms has been investigated. The pulmonary function of card room workers in 23 US cotton mills was tested before and after the Monday working shift. A significant relation was found between the delta FEV1.0 decrement and the vertical elutriator dust level in the different mills. An improved correlation was obtained when the number of Gram-negative bacteria cultured from the bale cotton used in the different mills was employed in the exposure description. The results support earlier epidemiological and experimental studies, which demonstrate the importance of the Gram-negative bacteria in the development of pulmonary symptoms among workers in cotton mills.
This article considers the development of cotton growing in the USSR as one of the leading branches of agriculture. The production of raw cotton and the yield of cultivated varieties of cotton reached a high level. Further increase in yield and increase in production of raw cotton are accompanied by the need to resolve a number of problems. In resolving them, a leading role will be played by science. The author enumerates the principal problems to which efforts of scientific-research institutions will have to be addressed.