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背景:热休克因子(Hsf)在植物生长和防御过程中具有重要作用。辣椒(Capsicum annuum L.)是重要的蔬菜作物,其产量和质量受高温、盐渍及渗透胁迫等环境胁迫影响而严重降低。尽管辣椒基因组测序已经完成,但Hsf家族在非生物胁迫条件下的作用尚不明确。结果:通过生物信息学分析及PCR检测,在辣椒基因组中共鉴定出25个CaHsf。根据Hsf的保守结构域,CaHsf可分为3类,分别是CaHsf A、CaHsf B和CaHsf C;除第11号染色体外,该家族基因在其他11条染色体上均有分布;除CaHsf A5外,该家族蛋白均能形成蛋白互作网络。据辣椒栽培种CM334的转录组数据,大部分CaHsf基因在根、茎、叶、果皮、胎座等组织中不止一处表达。q RT-PCR表明,除耐热株系R9叶片中的CaHsfC1外,所有CaHsf均响应高温胁迫(40℃,2 h);且其表达模式与热敏株系B6的CaHsf表达模式不同。许多CaHsf也受到盐胁迫、渗透胁迫、外源Ca~(2+)、腐胺、ABA和茉莉酮酸甲酯的调控。此外,CaHsfA2定位于细胞核,且具有转录活性,具有Hsf的典型特征。随时间变化,CaHsfA2响应高温胁迫的表达谱表明,CaHsfA2在辣椒热敏株系B6与耐热株系R9中的表达模式与表达水平均不相同。结论:从辣椒基因组中鉴定了25个Hsf,多数响应高温胁迫、盐胁迫、渗透胁迫及外源物质,为进一步研究辣椒CaHsf在各非生物胁迫中的功能及相应的信号转导途径奠定了基础。
Background: Heat shock factor (Hsf) plays an important role in plant growth and defense. Pepper (Capsicum annuum L.) is an important vegetable crop whose yield and quality are seriously affected by environmental stress such as high temperature, salinity and osmotic stress. Although pepper genome sequencing has been completed, the role of the Hsf family in abiotic stress is not yet clear. Results: By bioinformatics analysis and PCR detection, a total of 25 CaHsf were identified in pepper genome. According to the conserved domain of Hsf, CaHsf can be divided into three groups, namely CaHsf A, CaHsf B and CaHsf C. The gene of this family is distributed on 11 other chromosomes except chromosome 11; besides CaHsf A5, The family of proteins can form a protein interaction network. According to the transcriptional group data of pepper cultivars CM334, most of the CaHsf genes were expressed in more than one place in the roots, stems, leaves, pericarp and placenta. q RT-PCR showed that all CaHsf responded to high temperature stress (40 ℃, 2 h) except for CaHsfC1 in the R9 leaves of the heat-resistant strain, and the expression pattern of CaHsf was different from that of heat-sensitive strain B6. Many CaHsf are also under salt stress, osmotic stress, exogenous Ca 2+, putrescine, ABA and methyl jasmonate. In addition, CaHsfA2 is localized in the nucleus and is transcriptionally active, with typical features of Hsf. Over time, the expression profile of CaHsfA2 in response to high temperature stress showed that CaHsfA2 expression patterns and expression levels were different in heat-sensitive B6 and R9 lines. CONCLUSIONS: Twenty-five Hsf were identified from the genome of pepper, most of which responded to high temperature stress, salt stress, osmotic stress and exogenous substances, which laid the foundation for further study on the function and corresponding signal transduction pathway of pepper CaHsf in abiotic stresses .