干旱胁迫对不同抗旱性棉花品种抗氧化酶活性及基因表达的影响

Response of Antioxidant Enzyme Activities and Gene Expression in Different Drought Resistance Cotton Varieties under Drought Stress

为明确不同抗旱性棉花品种对干旱胁迫的适应性差异,该研究选用‘新陆早50号’(耐旱型)和‘新陆早27号’(干旱敏感型)为材料,分析干旱及复水处理下两材料的活性氧产生、电解质渗漏、抗氧化酶活性变化,并分析部分抗氧化酶基因、渗透调节基因和转录因子在干旱胁迫下的表达谱。结果显示:(1)棉花叶片的电导率和MDA含量随着干旱胁迫的加强逐渐增加,复水后恢复;在干旱胁迫处理6和8d,耐旱型品种‘新陆早50号’的抗氧化酶活性显著高于干旱敏感型品种‘新陆早27号’。(2)基因表达谱分析显示,棉花超氧化物歧化酶基因(GhSOD)仅在干旱胁迫下表达,且2个品种间差异不显著,GhBADH、GhNCED和GhP5Cs及转录因子GhPHD1、GhPHD5、GhPHD6和GhPHD10在‘新陆早50号’叶片中的表达量均高于‘新陆早27号’。研究表明,耐旱型棉花品种较干旱敏感型在干旱胁迫下其体内的活性氧含量、电导率和MDA含量较低,抗氧化酶活性较高,并且其抗旱相关基因表达量也更高。

In order to clarify the adaptable difference of different drought resistance cotton varieties under drought stress,we took ‘Xinluzao 50＇（drought-tolerant）and‘Xinluzao 27＇（drought sensitive）as the material in this test.The active oxygen species generation,electrolyte leakage,antioxidant enzyme activity change,and the expression profiles of some antioxidant enzymes genes,osmotic regulation genes,transcription factors were analyzed under drought stress.The results showed that：（1）the conductivity and MDA content in cotton leaves increased gradually with drought stress strengthen,and recovery after rehydration;the antioxidant enzyme activities of drought-tolerant variety‘Xinluzao 50＇significantly higher than that of drought sensitive variety‘Xinluzao 27＇after drought stress 6and 8days.（2）Gene expression profiling under drought and rewater treatment showed that cotton superoxide dismutase（GhSOD）only expressed under drought stress and had no difference between two varieties,GhBADH,GhNCED,GhP5 Cs and transcription factors GhPHD1,GhPHD5,GhPHD6,GhPHD10 in drought-tolerant variety ‘Xinluzao 50＇hadhigher expression level than that in drought sensitive variety‘Xinluzao 27＇.The results demonstrated that drought-tolerant variety had lower active oxygen content,conductivity and MDA content,higher antioxidant enzymes activity,and the expression of drought relate genes had higher level compared with drought sensitive variety under drought stress.