| 摘要: |
| 【目的】分析辣椒NAC转录因子CaNAC083在高温胁迫响应中的作用，为阐明辣椒耐高温机理奠定基础。【方法】以辣椒P70为材料，扩增CaNAC083基因，对其进行生物信息学分析，在辣椒中构建基因沉默载体沉默该基因，用RT-qPCR检测沉默效率以及高温胁迫相关基因CaHsfA2、CaHsfB5、CaHsp25.9和CaHSP90的相对表达量，测定42 ℃高温胁迫处理10 h前后丙二醛（MDA）含量、相对电导率、Fv/Fm、活性氧（H2O2和O-2·）含量以及抗氧化酶（超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT））活性的变化，观测二氨基联苯胺（DAB）和氮蓝四唑（NBT）染色情况；同时构建过量表达载体转化拟南芥，测定42 ℃高温处理12 h前后的MDA含量、活性氧含量、相对电导率以及抗氧化酶活性的变化，探讨CaNAC083基因对植株耐高温能力的影响。【结果】CaNAC083属于NAP亚家族的一员,且与典型的NAP亚家族成员的结构一致。CaNAC083基因沉默辣椒植株在高温胁迫后叶片损伤较轻，MDA、相对电导率以及活性氧均低于对照植株，而POD、SOD和CAT活性高于对照植株，CaHsfA2、CaHsfB5、CaHsp25.9和CaHSP90相对表达量均高于对照植株。过表达CaNAC083拟南芥株系在高温胁迫下受害程度较WT严重，MDA、相对电导率以及活性氧含量均高于WT，而POD、SOD和CAT活性均低于WT。【结论】CaNAC083基因沉默可以增强辣椒植株的耐高温性，过表达该基因则减弱植株的耐高温性，判断CaNAC083在植物高温胁迫中可能起负调控作用。 |
| 关键词: 辣椒 拟南芥 NAC转录因子 CaNAC083 基因沉默 高温胁迫 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目(32172582) |
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| Response of pepper transcription factor CaNAC083 to high temperature stress |
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HU Huifang,WANG Ziyu,PAN Xiaoxiao,et al
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| Abstract: |
| 【Objective】The role of pepper NAC transcription factor CaNAC083 in response to high temperature stress was analyzed to elucidate the mechanism of pepper heat resistance.【Method】The CaNAC083 gene of pepper P70 was amplified and its bioinformatics analysis was carried out.A gene silencing vector was constructed to silence the gene in pepper,and RT-qPCR was used to detect the silencing efficiency and expression levels of high temperature stress related genes CaHsfA2,CaHsfB5,CaHsp25.9 and CaHSP90.The content of malondialdehyde (MDA),relative conductivity,Fv/Fm,contents of reactive oxygen species (H2O2 and O-·2),as well as contents and activities of antioxidant enzymes including dismutase (SOD),peroxidase (POD) and catalase (CAT) before and after 42 ℃ high temperature stress treatment for 10 h were measured.The staining of diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) was observed.Then,the overexpression vector was transformed into Arabidopsis thaliana,and the changes of MDA content,reactive oxygen species contents,relative electrical conductivity and antioxidant enzyme activities before and after high temperature treatment at 42 ℃ for 12 h were measured to explore the effect of CaNAC083 gene on the high temperature tolerance of plants.【Result】CaNAC083 belonged NAP subfamily,and its structure was consistent with that of typical NAP subfamily members.CaNAC083 gene silenced pepper plants were more seriously injured after high temperature stress,with lower MDA,relative conductivity and reactive oxygen species but higher POD,SOD and CAT activities in comparison with control plants.The relative expressions of CaHsfA2,CaHsfB5,CaHsp25.9 and CaHSP90 were also higher than the control plants.The Arabidopsis lines overexpressing CaNAC083 wilted more seriously than wild plants (WT) under high temperature stress.The contents of MDA,relative conductivity and reactive oxygen species were higher than those of WT,while the activities of POD,SOD and CAT were lower than those of WT.【Conclusion】CaNAC083 gene silencing enhanced the high temperature tolerance of pepper plants,while overexpression of this gene weakened it.CaNAC083 may play a negative regulatory role in plants under high temperature stress. |
| Key words: pepper Arabidopsis NAC transcription factor CaNAC083 gene silencing high temperature stress |
