马铃薯磺肽素基因StPSK4的克隆及其抗病功能分析

Cloning and disease resistance function analysis of the phytosulfokine gene StPSK4 from potato

【目的】探究马铃薯磺肽素基因StPSK4特征及其在马铃薯抗病性中的功能分析,为马铃薯抗病育种提供理论依据。【方法】用生物信息学技术对StPSK4进行系统分析,转录组测序分析StPSK4的组织特异性、生物胁迫和非生物胁迫处理下的表达模式,检测StPSK4过表达植株对植物先天免疫反应情况和对青枯菌的敏感性。【结果】StPSK4基因的cDNA全长457 bp,编码100个氨基酸;StPSK4含有信号肽,其高级结构多由α-螺旋和无规则卷曲组成;PSK4的C端含有磺肽素序列DYIYTQ,StPSK4与茄科作物相似性均在80%以上;StPSK4在马铃薯芽和叶柄中高表达,对非生物胁迫(高温、盐)和生物胁迫(青枯菌、疮痂病菌)等响应剧烈;构建并获得过表达StPSK4的转基因马铃薯植株;过量表达StPSK4抑制马铃薯的ROS爆发、防御标记基因表达和对青枯病的抗病性。【结论】StPSK4可以响应高温和青枯病等多种逆境胁迫,过表达StPSK4抑制马铃薯的活性氧爆发、防御标记基因表达和对青枯病的抗性,证实StPSK4抑制马铃薯的抗病功能。

[Objective]The study aims to provide a theoretical basis for potato disease resistance breeding by investigating the characteristics of the potato defensin gene StPSK4 and conducting a functional analysis of its role in potato disease resistance.[Methods]The authors utilized bioinformatics method for a systematic analysis of StPSK4,and conduct transcriptome sequencing analysis to examine the tissue-specific expression pattern of StPSK4 under biotic and abiotic stress,assessing the plant innate immune response to Pseudomonas syringae in StPSK4 overexpressing plants.[Results]The full length CDS of StPSK4 was 457 bp,encoding 100 amino acids.StPSK4 contained a signal peptide,with its tertiary structure mainly composed ofα-helices and random coils.The C-terminus of PSK4 contains the defensin sequence DYIYTQ,and the similarity between StPSK4 and Solanaceae crops was above 80%.StPSK4 was highly expressed in potato sprouts and petioles,and showed strong response to biotic and abiotic stress such as high temperature,salt,P.syringae,and Phytophthora infestans.Overexpression of StPSK4 suppressed ROS burst in potato and defensed marker gene expression,and enhanced resistance to P.syringae.[Conclusion]StPSK4 responds to various stress conditions such as high temperature and bacterial wilt infestans.Overexpression of StPSK4 inhibits ROS burst,defense marker gene expression,and resistance to bacterial wilt in potato,confirming the suppressive role of StPSK4 in potato disease resistance.