activation of arabidopsis seed hair development by cotton fiber-related genes激活的拟南芥种子发发展棉花纤维相关的基因.pdfVIP

Activation of Arabidopsis Seed Hair Development by Cotton Fiber-Related Genes 1. 1. 1 1 2 1 Xueying Guan , Jinsuk J. Lee , Mingxiong Pang , Xiaoli Shi , David M. Stelly , Z. Jeffrey Chen * 1 Section of Molecular Cell and Developmental Biology and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America, 2 Department of Soil and Crop Sciences, Texas AM University, College Station, Texas, United States of America Abstract 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-overexpressin