摘要
苜蓿是最重要的豆科牧草,常被种植在干旱/半干旱地区。为研究不同耐旱性紫花苜蓿应对干旱胁迫的调控机制,本研究以中科1号紫花苜蓿(Medicagosativa‘Zhongke1’)为试验材料,以三得利紫花苜蓿(M.sativa‘Sanditi’)为对照,采用自然干旱法进行处理,比较干旱胁迫对其生长性状、光合作用、叶绿素含量、叶片相对含水量、渗透调节物质和抗氧化酶活性等指标的影响,并使用转录组测序分析2个品种响应干旱基因的差异。结果表明,干旱胁迫显著降低了2个紫花苜蓿品种的株高、地上地下生物量、叶片相对含水量、光合速率、蒸腾速率、气孔导度、胞间二氧化碳浓度和叶绿素含量;与三得利相比,干旱胁迫下中科1号紫花苜蓿丙二醛含量和电导率更低,渗透调节物质积累和活性氧清除能力更强。中科1号和三得利分别有5308个和8053个响应干旱的基因;GO功能注释分析发现,中科1号的346个干旱响应基因被显著富集在6个GO类别,而三得利的1683个干旱响应基因被显著富集在29个GO类别;此外,我们还筛选到19个在中科1号中表达量显著高于三得利的抗旱关键基因。本研究发现紫花苜蓿可能通过上调抗旱基因SUS、P5CS、LEA、SOD、POD、PEPC、NCED等的表达,提高渗透调节能力和抗氧化酶活性来维持相对较高的光合速率,从而增强抗旱能力。研究结果为进一步挖掘紫花苜蓿响应干旱胁迫的候选基因和抗旱育种提供了理论依据。
Alfalfa is the most important legume forage,which is often planted in aird or semi-arid regions.The objective of this study is to explore the responsive mechanism of alfalfa with different drought tolerance to drought stress,which provides the theoretical basis for tolerant breeding of alfalfa.In this study,the new variety Medicago sativa‘Zhongke 1’was used as the test material,and M.sativa‘Sanditi’was used as the control.The effects of drought stress on growth traits,photosynthesis,chlorophyll concentration,leaf water content,osmotic adjustment substances,and antioxidant enzyme activities were determined by natural drought strategy in pots.The deferentially expressed genes were compared by transcriptome analysis.Drought stress significantly reduced plant height,biomass,relative water content of leaves,photosynthetic rate,transpiration rate,stomatal conductance,intercellular carbon dioxide and chlorophyll concentration of alfalfa.Compared with Sanditi,Zhongke 1 revealed the lower malondialdehyde concentration and electrical conductivity under drought stress,but stronger osmotic regulation ability and superoxide radical scavenging ability.Transcriptome sequencing identified 5308 and 8053 drought-responsive genes of Zhongke 1 and Sanditi,respectively.GO functional annotation demonstrated that 346 drought-responsive genes were significantly enriched in six GO item categories in Zhongke 1,while 1683 drought-responsive genes in Sanditi were significantly enriched in 29 GO item categories.The relative expression levels of 19 key drought-tolerant genes in Zhongke 1 were significantly higher than those in Sanditi.Alfalfa may maintain a relatively high photosynthetic rate by up-regulating the relative expression levels of drought tolerant genes SUS,P5CS,LEA,SOD,POD,PEPC,and NCED,thus improving osmotic regulation ability and antioxidant enzyme activity.The results provide a theoretical basis for further exploration of alfalfa’s candidate genes in response to drought stress and drought tolerant breeding.
作者
陈力
王靖
邱晓
孙海莲
张文浩
王天佐
CHEN Li;WANG Jing;QIU Xiao;SUN Hai-Lian;ZHANG Wen-Hao;WANG Tian-Zuo(Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China;College of Life Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Inner Mongolia Academy of Agricultural&Animal Husbandry Sciences,Huhhot 010000,Inner Mongolia,China)
出处
《作物学报》
CAS
CSCD
北大核心
2023年第8期2122-2132,共11页
Acta Agronomica Sinica
基金
国家重点研发计划项目(2022YFF1003203)
内蒙古自治区科技计划项目(2021GG0372)资助。
关键词
紫花苜蓿
干旱胁迫
生理特性
转录组
alfalfa
drought stress
physiological characteristics
transcriptome
