Phylogenetically Distinct Cellulose Synthase Genes Support Secondary Wall Thickening in Arabidopsis Shoot Trichomes and Cotton Fiber

Abstract

Through exploring potential analogies between cotton seed trichomes (or cotton fiber) and arabidopsis shoot trichomes we discovered that CesAs from either the primary or secondary wall phylogenetic clades can support secondary wall thickening. CesA genes that typically support primary wall synthesis, AtCesA1,2,3,5, and 6, underpin expansion and secondary wall thickening of arabidopsis shoot trichomes. In contrast, apparent orthologs of CesA genes that support secondary wall synthesis in arabidopsis xylem, AtCesA4,7, and 8, are up-regulated for cotton fiber secondary wall deposition. These conclusions arose from: (a) analyzing the expression of CesA genes in arabidopsis shoot trichomes; (b) observing birefringent secondary walls in arabidopsis shoot trichomes with mutations in AtCesA4, 7, or 8; (c) assaying up-regulated genes during different stages of cotton fiber development; and (d) comparing genes that were co-expressed with primary or secondary wall CesAs in arabidopsis with genes upregulated in arabidopsis trichomes, arabidopsis secondary xylem, or cotton fiber during primary or secondary wall deposition. Cumulatively, the data show that: (a) the xylem of arabidopsis provides the best model for secondary wall cellulose synthesis in cotton fiber; and (b) CesA genes within a "cell wall toolbox" are used in diverse ways for the construction of particular specialized cell walls.Betancur L, Singh B, Rapp RA, Wendel JF, Marks MD, Roberts AW and Haigler CH (2010) Phylogenetically distinct cellulose synthase genes support secondary wall thickening in arabidopsis shoot trichomes and cotton fiber.

Functional Specialization of Cellulose Synthase Isoforms in a Moss Shows Parallels with Seed Plants

“…There are even examples of convergent evolution of secondary cell walls within the angiosperm lineage. Cotton (Gossypium hirsutum) fiber secondary cell walls are synthesized by the same CESAs that are responsible for secondary cell wall deposition in tracheary elements and fibers , whereas the secondary cell walls of epidermal trichomes are synthesized by the primary CESAs (Betancur et al, 2010). These observations are consistent with independent evolutionary origins for secondary cell walls in different land plant lineages and different cell types within angiosperm lineages.…”

Different combinations of multiple defence traits in an extrafloral nectary‐bearing plant growing under various habitat conditions

“…Our previous studies also showed that trichomes and pellucid dots were expressed well on plants that grew with low amounts of soil water (Yamawo, Hada & Suzuki 2012) and low nutrient conditions (Yamawo Bryant et al 1987). Trichomes fundamentally consist of cellulose (Betancur et al 2010). Pellucid dots typically contain toxic metabolic substances or essential oils (Wittstock & Gershenzon 2002;Schilmiller, Last & Pichersky 2008;Sirikantaramas, Yamazaki & Saito 2008).…”

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

“…It has a composition similar to the primary wall, although the cellulose content is slightly higher and the cellulose microfibrils are oriented in a cross-hatched, shallow helix along the longitudinal cell axis (Meinert and Delmer 1977;Wakelyn and French 2007). The genetic program supporting secondary wall cellulose synthesis is similar to the one used in sclerenchyma cells of the plant body (Betancur et al 2010), although cotton fiber secondary walls lack lignin and extensive matrix components. Toward the end of cotton fiber development, there is an ill-defined 'maturation' phase before the boll opens to allow final drying of the fiber in air (Haigler et al 2012).…”