Cotton Fiber Cell Walls of Gossypium hirsutum and Gossypium barbadense Have Differences Related to Loosely-Bound Xyloglucan

Abstract

Cotton fiber is an important natural textile fiber due to its exceptional length and thickness. These properties arise largely through primary and secondary cell wall synthesis. The cotton fiber of commerce is a cellulosic secondary wall surrounded by a thin cuticulated primary wall, but there were only sparse details available about the polysaccharides in the fiber cell wall of any cotton species. In addition, Gossypium hirsutum (Gh) fiber was known to have an adhesive cotton fiber middle lamella (CFML) that joins adjacent fibers into tissue-like bundles, but it was unknown whether a CFML existed in other commercially important cotton fibers. We compared the cell wall chemistry over the time course of fiber development in Gh and Gossypium barbadense (Gb), the two most important commercial cotton species, when plants were grown in parallel in a highly controlled greenhouse. Under these growing conditions, the rate of early fiber elongation and the time of onset of secondary wall deposition were similar in fibers of the two species, but as expected the Gb fiber had a prolonged elongation period and developed higher quality compared to Gh fiber. The Gb fibers had a CFML, but it was not directly required for fiber elongation because Gb fiber continued to elongate rapidly after CFML hydrolysis. For both species, fiber at seven ages was extracted with four increasingly strong solvents, followed by analysis of cell wall matrix polysaccharide epitopes using antibody-based Glycome Profiling. Together with immunohistochemistry of fiber cross-sections, the data show that the CFML of Gb fiber contained lower levels of xyloglucan compared to Gh fiber. Xyloglucan endo-hydrolase activity was also higher in Gb fiber. In general, the data provide a rich picture of the similarities and differences in the cell wall structure of the two most important commercial cotton species.

Comprehensive analysis of cellulose content, crystallinity, and lateral packing in Gossypium hirsutum and Gossypium barbadense cotton fibers using sum frequency generation, infrared and Raman spectroscopy, and X-ray diffraction

“…For G. hirsutum cv Deltapine90 and G. barbadense cv Phytogen 800 used in these experiments, the fiber of G. barbadense had the expected superior fiber qualities: greater length (1.27 vs. 1.15 in. upper half mean length), higher bundle strength (43 vs. 30 g/tex), and lower fineness (139 vs. 176 mTex, a measure of weight per unit length) as previously published (Avci et al 2013).…”

“…These varieties are representative of modern commercial cotton of each species, and as expected G. barbadense produces higher quality fiber under these growing conditions (Avci et al 2013) as summarized above. Flowers were tagged on the day of anthesis (flowering) in order to harvest fibers at successive DPA representing the major stages of cotton fiber development.…”

“…Given the prospects of using molecular tools to alter the properties of cotton fibers in novel ways, we need efficient and informative methods to reveal the chemical and biophysical properties of cotton fiber cell walls (Kljun et al 2011(Kljun et al , 2014Avci et al 2013;Abidi et al 2014;Kokot et al 2002;Hsieh et al 2000). In particular, many of the useful industrial properties of cotton fiber are conferred through the amount and biophysical properties of secondary wall cellulose, e.g.…”

“…For example, in comparison to G. hirsutum, G. barbadense fiber has less loosely-bound xyloglucan (Avci et al 2013) and pectin with a lower level of esterification near the onset of secondary wall deposition (Liu et al 2013). The density of crystalline cellulose (mass per unit volume) in the dried fibers of both species was similar (*1.52 g cm -3 ) (Peeters and De Langhe 1986).…”

A Cotton Annexin Affects Fiber Elongation and Secondary Cell Wall Biosynthesis Associated with Ca2+ Influx, ROS Homeostasis, and Actin Filament Reorganization

“…S10, A-F) suggest that cellulose synthesis may contribute to the advanced onset of SCW biosynthesis in the RNAi lines. Callose deposition not only is associated with the onset of SCW cellulose synthesis at 16 to 18 DPA but also is involved in plasmodesmata opening (Ruan et al, 2001;Zhang et al, 2004;Avci et al, 2013;Li et al, 2013a). Gluc1 is involved in callose degradation (Ruan et al, 2004) and was downregulated in overexpression transgenic lines but up-regulated in RNAi lines (Supplemental Fig.…”