砂藓RcPLD基因的抗旱功能分析  

Analysis of Drought-resistance Function of RcPLD Gene from Racomitrium canescens

作　　者：马天意 张时通 朱巍巍[1] 张梅娟[1] 李莹莹 彭疑芳 沙伟[1] MA Tianyi;ZHANG Shitong;ZHU Weiwei;ZHANG Meijuan;LI Yingying;PENG Yifang;SHA Wei(The Key Laboratory of Resistance Genetic Engineering and Coldland Biodiversity Conservation, College of Life Sciences, Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang 161006, China;College of Life Sciences, Northeast Agricultural University, Harbin 150030, China)

机构地区：[1]抗性基因工程与寒地生物多样性保护黑龙江重点实验室,齐齐哈尔大学生命科学与农林学院,黑龙江齐齐哈尔161006 [2]东北农业大学生命科学学院,哈尔滨150030

出　　处：《西北植物学报》2021年第7期1091-1100,共10页Acta Botanica Boreali-Occidentalia Sinica

基　　金：黑龙江省属高等学校基本科研业务费青年创新人才项目(135309364);黑龙江省属高等学校基本科研业务费植物性食品加工技术特色学科专项(YSTSXK201876);黑龙江省普通高等学校青年创新人才培养计划(UNPYSCT-2020073);黑龙江省人力资源和社会保障厅2018年省级留学回国人员择优资助项目。

摘　　要：砂藓(Racomitrium canescens)是一种具有极强耐脱水性的苔藓植物,编码磷脂酶D的基因RcPLD能够在砂藓的脱水和复水过程中产生显著的表达响应,它可能参与了砂藓的强耐脱水性功能。该研究使用已克隆的RcPLD编码序列构建拟南芥(Arabidopsis thaliana)过量表达转基因株系rcpld-oe,初步考察过表达株系的干旱胁迫耐受能力及其相关的生理生化指标,分析RcPLD增强拟南芥抗旱性的机制。结果表明:(1)利用已克隆的RcPLD编码序列构建了植物中的过表达载体,成功构建了RcPLD的过表达转基因拟南芥株系rcpld-oe,并获得了多个T3代rcpld-oe纯合体株系。(2)在正常生长条件下,rcpld-oe株系T3代纯合体植株比野生型拟南芥植株体积小,但营养生长期较长,抽薹较晚,莲座叶衰老速率较慢;在干旱处理条件下,rcpld-oe株系表现出比野生型拟南芥更强的干旱耐受能力。(3)在干旱胁迫处理过程中,rcpld-oe株系莲座叶的水分散失速率降低,可能在一定程度上降低了干旱对膜完整性的损伤和光合作用的抑制,但其渗透调节物质含量的变化相对较小。研究发现,在干旱胁迫条件下,rcpld-oe植株莲座叶的水分散失速率和光合作用抑制程度显著降低,从而表现出明显强于野生型的干旱耐受能力,这为后续RcPLD功能的深入研究和更多砂藓抗旱功能基因的挖掘奠定了基础。Racomitrium canescens is a bryophyte with extremely strong desiccation tolerance.The gene RcPLD from R.canescens was annotated coding a phospholipase D protein performed significant expression responses in the desiccation and rehydration processes,and supposed maybe participated in the strong desiccation-tolerance function of R.canescens.In this study,the cloned coding sequence of RcPLD was used for constructing the overexpression transgenic Arabidopsis thaliana lines rcpld-oe,the mechanism of the drought resistance in A.thaliana enhanced by RcPLD was preliminary analyzed by determining the drought stress tolerance and related physiological and biochemical indexes.The results showed:(1)the cloned coding sequence of RcPLD was used for constructing plant overexpression vector,the RcPLD overexpression transgenic A.thaliana lines,rcpld-oe,were successfully constructed,and many T3 generation homozygote rcpld-oe lines were obtained.(2)Under normal condition,T3 generation homozygote rcpld-oe lines performed smaller size,longer vegetative period,delayed bolting,and slower aging of rosette leaves comparing with wild-type plants;under the condition of drought treatments,rcpld-oe plants performed significantly better drought-tolerance than the wild-type A.thaliana.(3)In the process of drought treatments,it was found the water loss rate was lowered in rcpld-oe plants,damage on membrane integrity and inhibition of photosynthesis maybe decreased to a certain extent,but little was affected on the content of osmotic regulation substance.According to the research,under the condition of drought stress,water loss and photosynthesis inhibition in the rosette leaves of rcpld-oe plants were decreased,then performed the drought tolerance which was stronger than the wild-type A.thaliana.This laid research foundations for further researching more functions of RcPLD and discovering more drought-resistance function related genes in R.canescens.

关 键 词：砂藓 磷脂酶D基因(PLD) 干旱胁迫 抗旱功能分析 

分 类 号：Q785[生物学—分子生物学] Q786