Browsing by Subject "Cotton"

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Activation of Arabidopsis Seed Hair Development by Cotton Fiber-Related Genes
(Public Library of Science, 2011-07-11) Guan, Xueying; Lee, Jinsuk J.; Pang, Mingxiong; Shi, Xiaoli; Stelly, David M.; Chen, Z. Jeffrey
Each cotton fiber is a single-celled seed trichome or hair, and over 20,000 fibers may develop semi-synchronously on each seed. The molecular basis for seed hair development is unknown but is likely to share many similarities with leaf trichome development in Arabidopsis. Leaf trichome initiation in Arabidopsis thaliana is activated by GLABROUS1 (GL1) that is negatively regulated by TRIPTYCHON (TRY). Using laser capture microdissection and microarray analysis, we found that many putative MYB transcription factor and structural protein genes were differentially expressed in fiber and non-fiber tissues. Gossypium hirsutum MYB2 (GhMYB2), a putative GL1 homolog, and its downstream gene, GhRDL1, were highly expressed during fiber cell initiation. GhRDL1, a fiber-related gene with unknown function, was predominately localized around cell walls in stems, sepals, seed coats, and pollen grains. GFP:GhRDL1 and GhMYB2:YFP were co-localized in the nuclei of ectopic trichomes in siliques. Overexpressing GhRDL1 or GhMYB2 in A. thaliana Columbia-0 (Col-0) activated fiber-like hair production in 4–6% of seeds and had on obvious effects on trichome development in leaves or siliques. Co-overexpressing GhRDL1 and GhMYB2 in A. thaliana Col-0 plants increased hair formation in ~8% of seeds. Overexpressing both GhRDL1 and GhMYB2 in A. thaliana Col-0 try mutant plants produced seed hair in ~10% of seeds as well as dense trichomes inside and outside siliques, suggesting synergistic effects of GhRDL1 and GhMYB2 with try on development of trichomes inside and outside of siliques and seed hair in A. thaliana. These data suggest that a different combination of factors is required for the full development of trichomes (hairs) in leaves, siliques, and seeds. A. thaliana can be developed as a model a system for discovering additional genes that control seed hair development in general and cotton fiber in particular.
Characterization of apyrases in pea, arabidopsis, and cotton
(2010-05) Kays, Julia Elizabeth; Roux, Stanley J.; Clark, Gregory B.
Apyrases are proteins that bind to and hydrolyze most nucleoside di- and triphosphates, but not nucleoside monophosphates. Some function inside the cell; others hydrolyze extracellular nucleotides in the extracellular matrix. In Arabidopsis, apyrases and eATP have been implicated in diverse responses, ranging from phosphate mobilization to herbicide and toxin resistance to overall plant growth. Isolated garden pea nuclei exhibit phytochrome-dependent, red/far red-reversible changes in apyrase activity and in protein phosphorylation. O-linked β-N-acetylglucosamine (O-GlcNAc) is a post-translational modification that functions in a manner analogous but often antagonistic to O-phosphorylation. Given the known red light effects in pea nuclei and the link between O-GlcNAc and O-phosphorylation, we tested whether O-GlcNAc modification in pea nuclei might change in response to red light (Rc). Western blots showed that anti-O-GlcNAc antibody could sometimes recognize modifications in pea nuclei proteins, but not consistently. Experiments testing red light irradiation, O-GlcNAc transferase inhibitors, and GlcNAcase inhibitors all yielded similarly inconsistent results. As the project progressed we learned that the O-GlcNAc modification is very labile, and that this lability was the probable basis of the inconsistent results. Methods to overcome this technical problem were not readily available and so this project was not pursued further. A second project focused on identifying the members of the protein complexes associated with apyrase in partially purified nuclear preparations. The apyrase complex was isolated from etiolated seedlings of both Arabidopsis and pea by co-immunoprecipitation using antibodies raised against purified protein from each system. Apyrase activity was also compared in etiolated and red-light irradiated nuclei in both systems. For both experiments and in both systems, the complex of proteins associated with apyrase in etiolated and Rc-irradiated nuclei were not consistently different. The discovery of a cotton EST with a sequence similar to other plant apyrases opened a new line of investigation in a model system with fibers that are suited for the study of growth kinetics of single cells. This putative apyrase is expressed at high levels in elongating fibers but not in fibers that are not elongating or in ovules, suggesting that apyrase may influence cotton fiber elongation. Studies of fiber growth kinetics in the presence of inhibitors that block apyrase activity, chemical inhibitors of animal P2X-type purinoceptors, and anti-apyrase antibodies also favor this hypothesis. I cloned the full length cDNAs of GhApy1 and GhApy2. Antibodies raised against a suspected antigenic and variable sequence of GhApy1 were produced and confirmed to recognize native cotton apyrase. Crude protein isolated from pollen exhibited apyrase activity.
Chinese coolies in Cuba and Peru : race, labor, and immigration, 1839-1886
(2010-08) Narvaez, Benjamin Nicolas; Brown, Jonathan C. (Jonathan Charles), 1942-; Hu-DeHart, Evelyn; Garfield, Seth W.; Gurdiy, Frank A.; Deans-Smith, Susan; Hsu, Madeline Y.
This dissertation examines the experience of the tens of thousands of Chinese indentured laborers (colonos asiáticos or “coolies”) who went to Cuba and Peru as replacements for African slaves during the middle of the nineteenth century. Despite major sociopolitical differences (i.e., colonial slave society vs. independent republic without slavery), this comparative project reveals the common nature in the transition from slavery to free labor. Specifically, the indenture system, how the Chinese reacted to their situation, and how they influenced labor relations mirrored each other in the two societies. I contend that colonos asiáticos, while neither slaves nor free laborers, created a foundation for a shift from slavery to free labor. Elites in both places tried to fit the Chinese into competing projects of liberal “progress” and conservative efforts to stem this change, causing them to imagine these immigrant laborers in contradictory ways (i.e., free vs. slave, white vs. non-white, hard-working vs. lazy, cultured vs. morally corrupt). This ambiguity excused treating Asian laborers as if they were slaves, but it also justified treating them as free people. Moreover, Chinese acts of resistance slowly helped undermine this labor regime. Eventually, international pressure, which never would have reached such heights if the Chinese had remained passive, forced an end to the “coolie” trade and left these two societies with little option but to move even closer to free labor. That said, this work also considers the ways in which the differing socio-political contexts altered the Chinese experience. In particular, in contrast to Peru, Cuba’s status as a colonial slave society made it easier for the island’s elites to justify exploiting these workers and to protect themselves from mass rebellion. My dissertation places the histories of Cuba and Peru into a global perspective. It focuses on the transnational migration of the Chinese, on their social integration into their new Latin American host societies, as well as on the international reaction to the situation of immigrant laborers in Latin America.
Cotton utilization in women's apparel : gender, apparel purchase decisions, and fiber composition
(2012-12) Stewart Stevens, Sara Marisa 1976-; Krifa, Mourad
A cursory review of domestic apparel production data from ‘Cotton Counts Its Customers’ reports by The National Cotton Council of America showed a discrepancy between the amounts of cotton utilized in domestically produced women’s apparel and that for men’s apparel. It appeared that the men’s apparel sector had a higher percentage market share of cotton than women’s apparel. For both genders, cotton’s dwindling market share was similar to that of diminishing domestic US apparel production overall. Since the majority of apparel in the U.S. is imported, import data was obtained from the United States International Trade Commission and compiled with the domestic apparel data to offer a more expansive view of cotton’s market share and its use separated by gender. The compilation of domestic and import apparel data followed the overall trend of a higher percentage of weight of cotton being used in men’s apparel than in women’s. Challenging apparel categories which may offer potential for expanded utilization with increased performance were Coats, Underwear/Nightwear, Suits, and Dresses. In an attempt to add context to the apparel market data, we explored two stages of the apparel supply chain: the first at the retail setting, the second at the consumer purchase and wear decision level. At the retail level, we investigated the availability of fiber composition information and its use as a part of the assortment offered to consumers. Two stores were selected for this exploratory phase and retail availability by gender and fiber content were physically tallied in the two retail settings. In both retail assortments, there was no emphasis of fiber composition as part of the information offered to the consumer. For the consumer wanting to find cotton apparel in these two settings, prior knowledge regarding the feel or look of cotton would seem necessary to facilitate locating cotton among the assortment of apparel. Fiber blends can offer cotton-like appearance and hand, so fiber composition tags could give consumers certainty regarding the garments they are buying. In addition to the observations above, we also noted in both stores a prevalence of cotton in men’s apparel, and a larger presence of man-made fibers in women’s apparel, which reflects the overall market situation. Finally, the second exploratory stage focused on clothing diaries and a wardrobe inventory provided by a small purposeful sample of respondents to examine the role of fiber composition, cotton in particular, in the individual’s garment purchase and daily-use decisions. The findings suggested that fiber composition was an important part of the daily garment selection process, based upon the daily activity and a set of personal beliefs about what the diary respondent felt that fiber had to offer. Similar to the market data Results, in the Clothing Diary responses males showed a greater tendency to select both 100% cotton Tops and Bottoms than did the female respondents. Overall, cotton appeared challenged by man-made and other fibers when the respondents needed to “dress up”, to attend to athletic activity, or to satisfy the need for specific functionalities such as rapid drying.
Elucidating molecular mechanisms of seed development in Arabidopsis and fiber development in cotton
(2020-09-03) Ando, Atsumi; Chen, Z. Jeffrey; Jansen, Robert K; Qiao, Hong; Roux, Stanley J; Sung, Sibum; Vokes, Steven A
Seeds are important energy resource and source of fabric materials for humans. We intake more than 40% of calories as well as nutrients from various angiosperm seeds, and use cotton fibers derived from seed coats for the majority natural fabric materials. In this dissertation, I investigated two seed development mechanisms; imprinting effects on seed size in Arabidopsis and fiber cell differentiation from seed coats in cotton. Seed size is affected by genetic mutations and imprinting. Imprinting is a widespread epigenetic phenomenon in mammals and flowering plants, in which selected genes are differentially expressed between alleles in a parent-of-origin manner. ETHYLENE INSENSITIVE2 (EIN2) encodes an essential signal molecule that links the ethylene perception on endoplasmic reticulum (ER) to transcriptional regulation in the nucleus. Interestingly, EIN2 is an imprinted gene in both Arabidopsis and maize, and is maternally expressed in the endosperm. The function of most imprinted genes including EIN2 is largely unknown in plants. In chapter two, I show how the imprinted expression of EIN2 regulates seed size in Arabidopsis. Cotton (Gossypium spp.) is the largest renewable source of textile fiber in the world and it is also an important oil crop. Cotton fibers are made up of individual cells that are derived from ~30% of epidermal cells on surface of the cotton seed, which each elongate up to several centimeters. Efforts to understand the causes of this shift has been hampered by the difficulty of isolating fiber cells from epidermal cells at the earliest stages of development. In chapter three and four, I show the gene expression and RNA modification of various tissues as well as different stages of fibers including early stage fibers collected by Laser Capture Microdissection technology, to identify the underlying mechanism of fiber development in cotton. These results provide mechanistic insights into the imprinting effect of EIN2 on seed development and shed light on the early changes in gene activity controlling fiber development in cotton, which may help manipulate seed and fiber yields.
An exploratory analysis of the relationships between cotton fiber properties and needlepunched nonwoven characteristics
(2011-08) Padmaraj, Lakshmi; Krifa, Mourad; Xu, Bugao
Nonwovens represent one of the booming sectors in the textile industry today with a significant projected growth both domestically and globally. At present, cotton is supplanted by synthetic fibers in nonwovens, thereby limiting its utilization in an important market sector. One of the major challenges for cotton is the high variability and lack of uniformity associated with fiber properties. Currently, manufacturers do not take this variability into account while selecting cotton for nonwovens. Therefore, it is essential to understand the effect of fiber properties on the nonwoven fabric characteristics in order to address this problem of variability. Bridging this knowledge gap can help increase cotton’s market share in the nonwoven sector and maintain its competitiveness in the fiber market. This project was an exploratory study to investigate the effect of cotton fiber properties on nonwoven fabric properties. Twenty different samples of Upland cotton with various combinations of fiber length and maturity parameters were used for this research. The fabric mechanical properties – tensile and burst strength, pore structure characteristics and permeability were measured and investigated in this study. The relationships between various raw fiber properties and the measured fabric characteristics were analyzed. The breaking strength of the fabric showed significant relations with fiber length and maturity. Using multiple regression analysis, an equation was derived to predict the specific breaking strength of the fabric from the mean fiber length and maturity ratio values of its constituent fibers. Though bursting strength and permeability showed significant single relations with several fiber properties, the multiple regression analysis returned a single significant predictor in each case – fiber length and fabric density respectively. Results observed from this study show that the constituent fiber attributes have significant relationships with the nonwoven fabric characteristics. Taking these fiber properties into account during raw material selection for cotton nonwovens would be advantageous as manufacturers can optimize quality, and also predict final product characteristics. Future studies focusing on the inter-fiber interactions in cotton nonwovens, comparisons between 100% cotton and synthetic blended nonwovens etc. will help gain better understanding, and contribute towards improving cottons marketability and utilization in the nonwoven industry.