Phytosterols play an important role in plant growth and development, including cell division, cell elongation, embryogenesis, cellulose biosynthesis, and cell wall formation. Cotton fiber, which undergoes synchronous ...Phytosterols play an important role in plant growth and development, including cell division, cell elongation, embryogenesis, cellulose biosynthesis, and cell wall formation. Cotton fiber, which undergoes synchronous cell elongation and a large amount of cellulose synthesis, is an ideal model for the study of plant cell elongation and cell wall biogenesis. The role of phytosterols in fiber growth was investigated by treating the fibers with tfidemorph, a sterol biosynthetic inhibitor. The inhibition of phy- tosterol biosynthesis resulted in an apparent suppression of fiber elongation in vitro or in planta. The determination of phy- tosterol quantity indicated that sitosterol and campesterol were the major phytosterols in cotton fibers; moreover, higher con- centrations of these phytosterols were observed during the period of rapid elongation of fibers. Furthermore, the decrease and increase in campesterol：sitosterol ratio was associated with the increase and decease in speed of elongation, respectively, dur- ing the elongation stage. The increase in the ratio was associated with the transition from cell elongation to secondary cell wall synthesis. In addition, a number of phytosterol biosynthetic genes were down-regulated in the short fibers of ligon lintless-1 mutant, compared to its near-isogenic wild-type TM-1. These results demonstrated that phytosterols play a crucial role in cot- ton fiber development, and particularly in fiber elongation.展开更多
基金the National Natural Science Foundation of China (31130039, 30671258)the Genetically Modified Organisms Breeding Major Projects, China (2009ZX08009-118B)the Program for New Century Excellent Talents in University from the Ministry of Education, China (NCET-07-0712)
文摘Phytosterols play an important role in plant growth and development, including cell division, cell elongation, embryogenesis, cellulose biosynthesis, and cell wall formation. Cotton fiber, which undergoes synchronous cell elongation and a large amount of cellulose synthesis, is an ideal model for the study of plant cell elongation and cell wall biogenesis. The role of phytosterols in fiber growth was investigated by treating the fibers with tfidemorph, a sterol biosynthetic inhibitor. The inhibition of phy- tosterol biosynthesis resulted in an apparent suppression of fiber elongation in vitro or in planta. The determination of phy- tosterol quantity indicated that sitosterol and campesterol were the major phytosterols in cotton fibers; moreover, higher con- centrations of these phytosterols were observed during the period of rapid elongation of fibers. Furthermore, the decrease and increase in campesterol：sitosterol ratio was associated with the increase and decease in speed of elongation, respectively, dur- ing the elongation stage. The increase in the ratio was associated with the transition from cell elongation to secondary cell wall synthesis. In addition, a number of phytosterol biosynthetic genes were down-regulated in the short fibers of ligon lintless-1 mutant, compared to its near-isogenic wild-type TM-1. These results demonstrated that phytosterols play a crucial role in cot- ton fiber development, and particularly in fiber elongation.
