马铃薯气孔密度表皮模式因子StSTOMAGEN的克隆和功能分析  

Cloning and functional analysis of potato stomatal density epidermal patterning factor StSTOMAGEN

作　　者：王艳丽 谢天 张春丽 李娟娟 刘溢健 李红兵[2] 殷俐娜[2] 王仕稳[2] 邓西平[1,2] 可庆波 WANG Yanli;XIE Tian;ZHANG Chunli;LI Juanjuan;LIU Yijian;LI Hongbing;YIN Li’na;WANG Shiwen;DENG Xiping;KE Qingbo(College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100;Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100)

机构地区：[1]西北农林科技大学生命科学学院,陕西杨凌712100 [2]西北农林科技大学水土保持研究所,陕西杨凌712100

出　　处：《干旱地区农业研究》2020年第4期235-244,共10页Agricultural Research in the Arid Areas

基　　金：中国科学院“黄土高原土壤侵蚀与旱地农业国家重点实验室”开放基金(A314021402-2013);中国科学院“西部青年学者”B类项目(XAB2017B02)。

摘　　要：为了研究马铃薯EPFL9/StSTOMAGEN基因在气孔发育过程中的功能,从马铃薯品种大西洋中克隆得到气孔密度表皮模式因子StSTOMAGEN,将其通过农杆菌介导的遗传转化方法,在拟南芥中异位表达,对该基因的表达特性及功能进行分析。结果显示:StSTOMAGEN主要定位于细胞间隙和细胞核,并且它在顶端未展开叶中表达最多,表达量在1 d中呈现周期性变化,长日照条件下(16 h/8 h,光/暗),在授时因子为20 h时表达量最高;聚乙二醇(PEG)模拟干旱胁迫处理4 h后其表达量达到最高,而脱落酸(ABA)和NaCl胁迫处理后,其表达水平呈现出持续降低的趋势。功能鉴定表明,过表达StSTOMAGEN基因的拟南芥(ST)相对于野生型(WT)气孔密度增大63%~83%,光合速率增大36%~42%。此外,ST植株离体叶片的水分散失速率增大24%~55%,离体叶片H2O2含量也显著升高,约为野生型的50%~100%。干旱胁迫下,ST株系的光合速率、Fv/Fm和瞬时水分利用效率都显著低于野生型,其中光合速率降低55%~66%,Fv/Fm降低22%~50%,瞬时水分利用效率降低11%~12%。综上结果可知,表皮模式因子StSTOMAGEN通过正调控气孔密度而降低植物的抗旱性,该结果为后期通过基因编辑技术降低StSTOMAGEN基因的表达,培育抗旱节水型马铃薯新品种奠定理论基础。Secretion of small molecules in the epidermal patterning factor-like family(EPFL)play an important role in stomatal development.To study the function of potato EPFL9/StSTOMAGEN gene during stomatal development,we cloned and functionally characterized the stomatal density regulator StSTOMAGEN from potato(Atlantic)and transformed it into Arabidopsis by Agrobacterium-mediated genetic transformation.We found StSTOMAGEN was mainly inter cellular space and cell nucleus localized and had the highest expression level in the apical unexpanded leaves.Interestingly,StSTOMAGEN transcript was rhythmically expressed with a peak around Zeitgeber time(ZT)20 under long-day(16 h/8 h,light/dark)conditions.Expression of StSTOMAGEN was markedly down-regulated in response to abscisic acid(ABA)and sodium chloride(NaCl)treatments;however,upon the application of polyethylene glycol(PEG),the expression of StSTOMAGEN peaked at 4 h and then decreased gradually.Functional identification showed that the stomatal density of the StSTOMAGEN overexpression(ST)lines was significantly increased by 63%~83%,and led to elevated photosynthetic rateby 36%~42%.Moreover,ST lines showed more water loss(24%~55%)and hydrogen peroxide(H2O2)accumulation(50%~100%)in detached leaves compared with wild-type(WT)plants.Under drought stress,ST lines maintained lower photosynthetic rates(55%~66%),photosystemⅡefficiency(22%~50%),and instantaneous water use efficiency(111%~12%)than WT plants did.Taken together,the results showed that the epidermal patterning factor StSTOMAGEN reduced drought tolerance of plants by positively regulating stomatal density.This result laid a theoretical foundation for reducing the expression of StSTOMAGEN gene and cultivating drought-resistant and water-saving potato strains by gene editing technology in the later period.

关 键 词：气孔密度 StSTOMAGEN 抗旱性 马铃薯 

分 类 号：S532[农业科学—作物学]