摘要
探究甜高粱响应干旱与盐胁迫的生理学差异及其分子机制,分析甜高粱在干旱和盐胁迫下的不同基因调控机制和代谢通路,可为饲草作物甜高粱抗逆栽培和育种提供依据。以辽甜1号甜高粱幼苗为材料,使用10%的PEG-6000和0.9%的NaCl模拟中度干旱和盐胁迫,胁迫2和7 d时进行光合气体交换参数、内源激素含量、有机渗透调节物质含量和抗氧化物酶活性测定,同时对幼苗叶片进行转录组测序及生物信息学分析,采用qRT-PCR方法对测序结果进行验证。结果表明:与对照相比,干旱和盐胁迫均显著影响甜高粱幼苗叶片生理指标的变化,但盐胁迫对甜高粱幼苗叶片光合参数和内源激素生长素、细胞分裂素含量抑制程度均高于干旱胁迫,可溶性糖含量在干旱胁迫下显著高于盐胁迫,抗氧化物酶活性和脱落酸含量低于盐胁迫,说明甜高粱对干旱和盐胁迫响应的生理机制不同;利用转录组测序技术鉴定出甜高粱叶片在处理2 d时,干旱和盐胁迫下分别有922和2047个上调基因以及975和1714个下调基因,处理7 d时分别鉴定到157和795个上调基因以及54和722个下调基因;同时鉴定出40个干旱胁迫响应基因和493个盐胁迫响应基因,基于GO富集分析发现甜高粱幼苗在干旱和盐胁迫下响应基因均显著富集于植物逆境响应相关通路,KEGG富集分析发现,干旱胁迫响应基因显著富集于内质网加工和剪切体代谢通路,盐胁迫响应基因显著富集在植物激素信号转导代谢通路;对光合作用、植物激素信号转导、抗氧化物酶和淀粉与蔗糖代谢通路相关差异基因进行分析发现,这些差异基因的表达模式与生理指标变化趋势吻合。因此,甜高粱在转录水平上对盐胁迫的适应稳态落后于干旱胁迫,中度胁迫下甜高粱幼苗对盐胁迫的耐受性要低于干旱胁迫,可溶性糖在甜高粱幼苗抵御干旱胁迫中发挥重要作用,植物激素信号转导和�
This research aimed to explore the molecular mechanisms,metabolic pathways and physiological differences of responses to drought and salt stress in sweet sorghum,in order to strengthen the scientific information available to enhance sweet sorghum forage crop husbandry and breeding.Seedlings of sweet sorghum cultivar Liaotian No.1 were used to provide the plant material for study.Moderate drought stress was induced using 10%PEG-6000 solution and salt stress was simulated using 0.9% NaCl solution.Photosynthetic gas exchange parameters,endogenous hormone content,content of organic osmotic regulatory substances and antioxidant enzyme activities were determined on days 2 and 7 of stress exposure.Concurrently,transcriptome sequencing and bioinformatics analyses were carried out on seedling leaves,and qRT-PCR was used to verify the sequencing results.For sweet sorghum seedlings under salt stress,photosynthetic parameters,endogenous auxin concentration and degree of cytokinin inhibition were higher than under drought stress;Soluble sugar content was significantly higher under drought stress than under salt stress;Antioxidant enzyme activities and abscisic acid concentrations were higher under salt stress than under drought stress,indicating different physiological mechanisms of drought and salt stress response in sweet sorghum.Under drought stress on day 2,transcriptome sequencing identified 922 upregulated and 975 down-regulated genes while under salt stress there were 2047 up-regulated and 1714 downregulated genes.At day 7 under drought stress there were 157 up-regulated and 54 down-regulated genes while under salt stress there were 795 up-regulated and 722 down-regulated genes.Forty drought stress response genes and 493 salt stress response genes were also identified.Gene ontology(GO)-based enrichment analysis revealed that sweet sorghum seedlings under drought and salt stress were significantly enriched in pathways involving plant response to stress.Kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis sho
作者
王志恒
魏玉清
赵延蓉
王悦娟
WANG Zhi-heng;WEI Yu-qing;ZHAO Yan-rong;WANG Yue-juan(College of Biological Science and Engineering,North Minzu University,Yinchuan 750021,China)
出处
《草业学报》
CSCD
北大核心
2022年第3期71-84,共14页
Acta Prataculturae Sinica
基金
国家自然科学基金(31960387)
北方民族大学高层次人才项目(2019BJLZ02)资助。
关键词
甜高粱幼苗
干旱胁迫
盐胁迫
生理
转录组分析
sweet sorghum seedlings
drought stress
salt stress
physiology
transcriptomic analysis
