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草业学报 ›› 2023, Vol. 32 ›› Issue (10): 93-103.DOI: 10.11686/cyxb2023019

• 研究论文 • 上一篇    下一篇

干旱胁迫下不同性别野牛草生理及抗氧化酶基因表达差异

刘牧野1(), 郭丽珠2, 岳跃森2, 武菊英2, 范希峰2, 肖国增1(), 滕珂2()   

  1. 1.长江大学园艺园林学院,湖北 荆州 434052
    2.北京市农林科学院,草业花卉与景观生态研究所,北京 100097
  • 收稿日期:2023-01-06 修回日期:2023-03-03 出版日期:2023-10-20 发布日期:2023-07-26
  • 通讯作者: 肖国增,滕珂
  • 作者简介:E-mail: tengke.123@163.com
    E-mail: x_gz99@163.com
    刘牧野(1999-),男,安徽六安人,在读硕士。E-mail: lmy6511999@163.com
  • 基金资助:
    国家自然基金(31901397);北京市农林科学院科技创新能力建设专项(20210439)

Physiological and antioxidant enzyme gene expression differences between female and male Buchloe dactyloides plants under drought stress

Mu-ye LIU1(), Li-zhu GUO2, Yue-sen YUE2, Ju-ying WU2, Xi-feng FAN2, Guo-zeng XIAO1(), Ke TENG2()   

  1. 1.The College of Horticulture and Garden,Yangtze University,Jingzhou 434052,China
    2.Institute of Grassland,Flowers and Ecology,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,China
  • Received:2023-01-06 Revised:2023-03-03 Online:2023-10-20 Published:2023-07-26
  • Contact: Guo-zeng XIAO,Ke TENG

摘要:

干旱是制约植物生长的重要胁迫因素之一,目前对于不同性别野牛草抗旱的生理及分子差异机制的研究较少,为探究干旱胁迫下野牛草雌、雄株抗氧化酶活性以及基因表达差异,以野牛草“Texoka”品种为试验材料,测定干旱第0、7、14天以及复水7 d后野牛草雌、雄株叶片相对含水量(RWC)、叶绿素含量(Chl)、PSII最大光化学量子效率(Fv/Fm)以及抗氧化酶活性,利用qRT-PCR技术研究了野牛草雌、雄株抗氧化酶基因在不同干旱时间下的表达差异。结果表明,干旱胁迫下野牛草雌、雄株坪观质量随着干旱时间的延长而降低,复水后恢复,且雌株坪观质量强于雄株。野牛草雌、雄株RWC都随着干旱处理时间增加而下降,复水后恢复,在干旱第7天雌株RWC高于雄株。野牛草雌、雄株Chl含量随着干旱-复水处理都呈下降趋势;Fv/Fm在干旱-复水处理过程中呈相同的趋势,在干旱第14天均显著降低。雌、雄株Chl和Fv/Fm除第7天外均没有显著差异,两者在长期干旱胁迫以及复水后光合特性相似。野牛草雌株超氧化物歧化酶(SOD)活性在干旱第7、14天以及复水7 d后都高于雄株,雌株抗坏血酸过氧化物酶(APX)活性变化更加明显,证明野牛草雌株应对干旱胁迫时APX更快积累;在干旱胁迫下雌、雄株过氧化物酶(POD)活性变化一致,两者没有显著差异。干旱第7天后,野牛草雌、雄株过氧化氢酶(CAT)活性变化趋势完全相反。实时荧光定量PCR分析表明,野牛草雌株抗氧化酶基因表达量在复水后达到峰值,与抗氧化酶活性变化并不一致;雄株FeSOD、Zn/Cu-SOD、POD相对表达量在干旱第14天达到峰值,与抗氧化酶活性变化相同。雄株APX以及CAT相对表达量在干旱第0天最高后下降,复水后上升,与抗氧化酶活性变化不一致。总体而言,野牛草雌、雄株之间在生理及分子水平上对干旱胁迫的响应存在一定差异,且野牛草雌株抗旱性强于雄株。本研究丰富了野牛草抗氧化系统响应干旱胁迫的认识,并为研究雌雄异株植物的抗旱机制提供了参考。

关键词: 野牛草, 干旱胁迫, 抗氧化酶, 基因表达, 性别差异

Abstract:

Drought is one of the important stress factors that restrict plant growth. At present, there are few studies on the physiological and molecular mechanisms of drought resistance of buffalo grass (Buchloe dactyloides) plants of different genders. To investigate the differences in the effects of drought stress on male and female buffalograss, we studied the ‘Texoka’ cultivar in terms of antioxidant enzyme activity and gene expression. The changes in relative water content (RWC), chlorophyll (Chl) content, the maximum quantum yield of PSII (Fv/Fm) and antioxidant enzyme activities were determined under drought stress for 0, 7, 14 days and 7 days after re-watering. In addition, the expression levels of antioxidant enzyme coding genes of female and male buffalograss in response to drought stress were investigated using qRT-PCR. The results showed that the turf quality of female and male plants decreased with the duration of drought stress, but recovered after rewatering. The turf quality of female plants was better than that of male plants. RWC of both female and male plants decreased with increase in drought exposure time but showed recovered after rewatering. RWC of female plants was significantly higher than that of male plants on the 7th day of drought treatment. Chl of female and male buffalograss decreased during the drought-rehydration treatment. Fv/Fm showed the same trend during the drought-rehydration treatment, with a significant decrease on the 14th day of drought. There was no significant difference in Chl and Fv/Fm between female and male plants except on the 7th day, and the photosynthetic characteristics of both plants were similar after long-term drought stress and rewatering. The photosynthetic characteristics of both genders were similar under long-term drought stress and after re-watering. In detail, the activity of superoxide dismutase in female buffalograss was higher than that in male buffalograss at 7 and 14 d of drought stress and 7 d after re-watering. The activity of ascorbate peroxidase (APX) in female buffalograss was higher than in male plants indicating that APX accumulated faster in female buffalograss under drought stress. The activity of peroxidase of female and male buffalograss plants showed the same time course under drought stress, with no significant difference between them. The time course of catalase activity of female and male plants was completely opposite on the 7th day of drought. The expression of antioxidant enzyme genes in female buffalograss peaked after re-watering, which was inconsistent with the change of antioxidant enzyme activity. The expression of FeSOD, Zn/Cu-SOD and POD of male buffalograss peaked in each case on the 14th day of drought, and was in accordance with the pattern of antioxidant enzyme activities. The expression of APX and CAT in male seedlings decreased from the imposition of drought and increased after re-watering, but was inconsistent with the changes in antioxidant enzyme activities which needs further investigation. In general, physiological and transcriptional differences were found between female and male buffalograss in response to drought stress. The drought resistance of female buffalograss was stronger than male buffalograss. This study enriched our knowledge of the mechanism of antioxidant systems in buffalograss under drought stress, and provided reference data of potential ecological significance for the study of drought resistance strategies in dioecious plants.

Key words: Buchloe dactyloides, drought stress, antioxidant enzymes, gene expression, gender difference