棉花GhDIS2基因的克隆与酵母表达

Molecular Cloning and Characterization of GhDIS2 in Cotton

棉花纤维由胚珠外被单个表皮细胞分化发育而成,其分化和伸长涉及细胞骨架的重排。本研究根据已报道的植物DISTORTED2基因,同源候选基因法克隆棉花GhDIS2。该基因包括975bpORF,编码324个氨基酸。qPCR分析表明,它在陆地棉TM-1不同来源的组织中均表达,于开花后12d的纤维中达到表达高峰,开花后18d表达开始下降,根和茎的表达量较低。Southern杂交结果表明,GhDIS2在四倍体棉花基因组中存在2个拷贝。克隆GhDIS2到酵母表达载体中,并转化到裂殖酵母中,诱导该基因过量表达,GhDIS2促使细胞扩大。初步推测,GhDIS2和其它植物DIS2功能相似,参与植物细胞肌动蛋白骨架的组装。

Cotton fibers are single-celled seed trichomes of major economic importance. Many important genes are expressed during cotton fiber development. DISTORTED2 encodes the Arabidopsis homolog of the ARPC2 subunit of the ARP2/3 complex, which binds to the sides of existing actin filaments and efficiently nucleates new filaments. The cytoskeleton arrangement processes in the cotton fiber initial and elongation. In this study, the Gossypium homology of the ARPC2 subunit named as GhDIS2 was isolated from the TM-1 ovule on the day of flowering. GhDIS2 contained 975 bp open reading frame, encoding a polypeptide containing 324 amino acids. GhDIS2 was expressed constitutively in every tissue with different expression levels, with the peak in 12 days post anthesis （DPA） fiber cells and low expression levels in 18, 24 DPA fiber cells, roots and stems. Southern blotting showed that GhDIS2 had two copies in allotetraploid cotton genome. A shuttle vector contained GhDIS2 cD- NA sequence was transformed into fission yeast. GhDIS2 led to a significant increase in cell length and width. These results in- dicated that GhDIS2 had the same function to DIS in other plants.