摘要
甜叶菊被誉为“世界第三大糖源”,具有重要的经济价值,但其生长对水分胁迫十分敏感,因而限制其进一步推广。AP2/ERF转录因子是植物特有的一类转录因子,其中DREB亚家族蛋白被广泛报道可以提高植物非生物胁迫抗性。本研究在甜叶菊中克隆了拟南芥AtDREB2A同源基因SrDREB2A,该基因编码区长度为903 bp,编码301个氨基酸残基。系统进化树分析将其归类于DREB亚家族的A-2亚组,与青蒿的AaDREB2亲缘关系最近,并且包含一个典型的AP2结构域。SrDREB2A在甜叶菊叶片中表达量最高,并且受水分胁迫显著诱导。SrDREB2A蛋白定位于细胞核,具有转录激活活性,进一步发现100 mmol/L高浓度的3AT(3-氨基-1,2,4-三唑)不能抑制其转录激活活性。对SrDREB2A全长序列进行截断,结果发现其转录激活活性区段位于211~301 aa,而1~210 aa区段不具有激活活性,此无激活活性区段可用于后续的酵母双杂交筛库。以上研究为通过分子生物学手段提高甜叶菊耐旱性提供了基因资源,并且为进一步研究SrDREB2A的分子功能奠定基础。
Stevia is regarded as the third generation of natural sugar resource with great economic values.However,stevia growth is very sensitive to water stress which limits its further expanding and utilization.AP2/ERF proteins are plant-specific transcription factors,of which the DREB subfamily members are participated in the improvement of abiotic stress resilience.In this study,we cloned the homologous gene of AtDREB2A in stevia and assigned as SrDREB2A with coding region of 903 bp in length which encodes 301 amino acid residues.Phylogenetic analysis revealed that SrDREB2A was classified into the A-2 subgroup of DREB subfamily characterized by the conserved AP2 domain and closest to AaDREB2 of Artemisia annua.SrDREB2A is predominantly expressed in leaves and conspicuously induced by dehydration.Subcellular localization analysis showed that SrDREB2A was specifically localized in the nucleus.SrDREB2A exhibits strong transactivation activity in yeast cells which was conferred by the 211-301 aa region.Domain dissection analysis confirmed that the 1-210 aa region has no transactivation activity,and therefore serves as potential platform for Y2H screening to identify putative interactive partners.This research provides essential gene resource for the genetic improvement of drought tolerance of stevia and lays foundation for exploration of the molecular function of SrDREB2A in the future.
作者
张婷
杨永恒
孙玉明
徐晓洋
王银杰
张永侠
原海燕
ZHANG Ting;YANG Yongheng;SUN Yuming;XU Xiaoyang;WANG Yinjie;ZHANG Yongxia;YUAN Haiyan(Institute of Botany,Jiangsu Province and the Chinese Academy of Sciences/Nanjing Zhongshan Botanical Garden,Nanjing 210014)
出处
《中国糖料》
2022年第4期1-7,共7页
Sugar Crops of China
基金
国家自然科学基金青年基金(31901597)
江苏省自然科学基金面上基金(BK20201243)资助。
