Accumulation And Structural Unit Of Wall-Linked Phenolics In The Cotton (Gossypium Hirsutum) Fiber Secondary Wall

The development of secondary cell wall and final composition affects the quality of mature cotton fiber. The previous studies reported that the biosynthesis of phenolic compounds occur throughout the development of cotton fiber secondary wall. This study investigated the accumulation and structural unit of wall-linked phenolics in the cotton fiber secondary wall. The accumulation of phenolics in cotton fibers within a single boll increased along with the fiber development from 20 days postanthesis (DPA) to maturity. The method, which the wall-linked phenolics was observed thoroughly by fourier transform infrared spectroscopy (FTIR) after treated by thioglycolic acid (TGA), was established. The result showed that the cell wall phenolics of cotton fiber consisted predominantly of guaiacyl units (G) with some syringyl units (S). The results of derivatization followed by reductive cleavage (DFRC) confirmed G and some S units existed in the cell wall of cotton fiber. The nuclear magnetic resonance (NMR) showed connection ways between G and S were C-C bond of beta-5 and beta-beta, and ether linkage of beta-O-4. Gel permeation chromatography (GPC) indicated the average molecular weight (Mw) distribution range of wall-linked phenolics with 1023-2169 g mol(-1), while number-average molecular weight (Mn) was 900-1970 g mol(-1) and the polyclispersity coefficient was 1.09-1.74. (C) 2019 Friends Science Publishers