《植物生理学报》 2021, 57(1): 205-215

海岛棉GbGAI4-A6基因在体细胞胚胎发生中的功能研究

杨瑞思，李禾钱，柳涛，何美莹，陈全家，曲延英，张霞^*

新疆农业大学农学院, 农业生物技术重点实验室, 乌鲁木齐830052

通信作者：张霞；E-mail: xiazhangxjnd@sohu.com

摘　要：

DELLA蛋白是GA信号通路中的重要调节因子。前期研究中, 我们从海岛棉‘新海16’体细胞胚胎发生不同阶段转录谱数据中筛选出上调表达的差异基因DELLA蛋白基因GbGAI4-A6。该基因全长1 617 bp, 编码538个氨基酸, 与陆地棉GhGAI4氨基酸序列同源性最高, 同源性为99.94%。亚细胞定位结果表明Gb-GAI4-A6-GFP荧光信号定位于植物细胞核。qRT-PCR结果显示GbGAI4-A6基因在‘新海16’体细胞胚胎发生不同阶段都有表达, 在胚性愈伤组织阶段表达量较高。糖皮质激素(DEX)可高效诱导GbGAI4-A6在海岛棉转基因胚性细胞中的过量表达或抑制表达, 进一步细胞学观察结果表明, GbGAI4-A6基因过量表达的转基因胚性细胞保持原有胚性细胞形态, 而GbGAI4-A6基因的抑制表达则促进转基因细胞由胚性细胞形态向非胚性细胞形态转变, 暗示了GbGAI4-A6基因在细胞内的表达量与细胞分化方向具有相关性。

关键词：海岛棉; 体细胞胚胎发生; GbGAI4-A6; 亚细胞定位; 表达模式; 功能研究

收稿：2020-07-22   修定：2020-10-26

资助：国家自然科学基金(31660078和32060044)和自治区天山创新团队计划(2020D14002)

Functional identification of GbGAI4-A6 gene in Gossypium barbadense somatic embryogenesis

YANG Ruisi, LI Heqian, LIU Tao, HE Meiying, CHEN Quanjia, QU Yanying, ZHANG Xia^*

College of Agriculture / Key Laboratory of Agricultural Biotechnology, Xinjiang Agricultural University, Urumqi 830052, China

Corresponding author: ZHANG Xia; E-mail: xiazhangxjnd@sohu.com

Abstract:

DELLA protein is an important regulator of Gibberellins (GA) signaling. In previous study, we have identified one differentially expressed gene, GbGAI4-A6, from the transcriptome of Gossypium barbadense ‘Xinhai16’ somatic embryogenesis. GbGAI4-A6 includes a 1 617 bp open reading frame encoding 538 amino acids, and the phylogenetic tree analysis displayed that GhGAI4 had the highest homology (99.94%) with GhGAI4 form Gossipium hirsutumin. The subcellur localization assay indicated that the fluorescence of GbGAI4-A6-GFP concentrated in the nucleues of onion epidermal cells. The results of qRT-PCR showed that GbGAI4-A6 gene was expressed in all the somatic embryigenesis process, but the highest in embryogenic cell-stage. Glucocorticoid (DEX) could effectively induce the over- or suppressed-expression of GhGAI4 in transgenic G. barbadense embryogenic cells, and further cytological observation results exhibited that the transgenic embryogenic cells with GbGAI4-A6 overexpression remained their embryonic cell-microstructure, whereas suppressed expression of GbGAI4-A6 conferred the cells transformation from embryonic cell- into non-embryonic cell-microstructure, demonstrating that expression of GhGAI4 is associated with differentiation direction of the cells in G. barbadense.

Key words: Gossypium barbadense; somatic embryogenesis; GbGAI4-A6; subcellular localization; expression pattern; functional identification