三浅裂野牵牛植物防御素基因家族鉴定及表达分析

Identification and Expression Analysis of Plant Defensin Gene Family in Ipomoea trifida

植物防御素普遍存在于植物中,是植物先天免疫的组成部分,具有抗真菌、细菌及抑制蛋白酶活性等作用,在植物生长发育、抗病、逆境胁迫应答中发挥重要作用。为了在甘薯中开展相关分子生物学研究及抗逆性分子育种,为植物防御素在抗菌类药剂生产研发、植物保护等方面开展相关研究工作奠定基础,对甘薯(Ipomoea batatas(L.)Lam.)近缘野生种三浅裂野牵牛(Ipomoea trifida)全基因组水平的植物防御素基因PDF家族成员进行鉴定和表达分析。结果表明,在其基因组中共鉴定到15个防御素蛋白,其等电点变化范围为7.56~9.30,表明这些蛋白质均呈弱碱性。染色体定位发现,这15个ItfPDFs基因不均匀分布于4条染色体上(Chr03、Chr06、Chr13和Chr14)。转录组数据分析表明,ItfPDF14在愈伤组织、根、茎、叶、花中均有表达,并且能够响应不同非生物胁迫,推测ItfPDF14可能在三浅裂野牵牛生长发育及非生物胁迫响应中发挥着重要功能。ItfPDF11、ItfPDF13、ItfPDF14和ItfPDF15可能参与调控三浅裂野牵牛的花芽发育。在进化过程中,基因片段复制可能是该基因家族成员扩张的重要方式。

Plant defensin is commonly found in plants,and it is the component of the innate immunity of plants,serving functions such as antifungal,antibacterial,and protease inhibition,and playing important roles in plant growth and development,disease resistance,and stress response.In order to provide a reference basis for molecular biology research and resistance breeding in sweet potatoes and lay a foundation for research and development of plant defensin the production of antimicrobial agents and plant protection,in this study,the members of the plant defensin gene(PDF)family was identified and analyzed at the genome-wide level in Ipomoea trifida,a species related to sweet potato(I.batatas(L.)Lam).The results showed that there were 15 plant defensin proteins in the genome and their isoelectric point ranged from 7.56 to 9.30,indicating that these proteins were alkaline.Chromosome localization analysis revealed that the 15 ItfPDFs genes were unevenly distributed across four chromosomes(Chr03,Chr06,Chr13,and Chr14).Based on transcription data,the expression of ItfPDF genes under different tissue types(callus-follower,callus-stem,flower,flower bud,leaf,root,and stem)was found and they could respond different abiotic stress,inferring that ItfPDF could play an important role in growth and development,and abiotic stress response of Ipomoea trifida.ItfPDF11,ItfPDF13,ItfPDF14,and ItfPDF15 might also play roles in flower bud development of Ipomoea trifida.In the process of evolution,gene fragment replication could be an important mechanism for the members of the ItfPDF gene family.