西瓜类甜蛋白家族全基因组鉴定及表达

Genome-wide identification and expression of thaumatin-like protein gene family in watermelon

【目的】对西瓜类甜蛋白家族基因(ClTLP)进行全基因组鉴定和序列特征及聚类分析,研究其在西瓜不同组织及病原菌胁迫下的表达模式,为进一步开展类甜蛋白家族基因的功能鉴定及其与枯萎病菌互作机制研究奠定基础。【方法】利用生物学软件对ClTLP进行序列特征及聚类分析,采用qRT-PCR技术检测ClTLP基因在西瓜根、茎、叶组织及枯萎病菌侵染不同时间(0,12,24,48,120,168 h)后的表达情况。【结果】从西瓜基因组中共鉴定到28个西瓜TLP家族基因,TLP基因分布在8条染色体上,主要有4种结构类型,蛋白保守,氨基酸基序高度一致。在基因启动子区发现多个激素响应元件和胁迫响应元件。西瓜类甜蛋白归属10个聚类群。多数ClTLP基因在西瓜不同组织中表现为组成型表达,在根中的表达量高于茎和叶片。枯萎病菌侵染可以诱导大部分ClTLP基因的表达,且多数基因表达量在侵染后120 h最高。其中,Cla97C01G019790和Cla97C10G185250的表达随枯萎病菌侵染时间延长逐渐升高,而Cla97C10G204510和Cla97C10G185260的表达受到了枯萎病菌胁迫抑制。【结论】西瓜类甜蛋白家族有28个成员,其大多数CITLP基因的表达量在根中最高,可受枯萎病菌诱导,在西瓜抵御病原菌侵染过程中发挥重要作用。

【Objective】This work identified watermelon TLP gene family through genome-wide analysis,analyzed sequence characteristics,and analyzed their expression patterns in different watermelon tissues under stress of Fusarium oxysporum.【Method】Genome-wide identification of watermelon TLP gene family and their sequence characterization were analyzed via bioinformatics tools.Gene expression profiles in watermelon root,stem,leaf tissues and at different time point(0,12,24,48,120 and 168 h)after Fusarium oxysporum inoculation were conducted by real-time PCR technique.【Result】A total of 28 ClTLP gene family members were identified from the watermelon genome data.They distributed on 8 chromosomes with 4 structural types and their proteins conserved amino acid motif was highly consistent.Putative cis-acting elements in the promoter region of TLP genes analysis showed several phytohormone responsive elements and stress responsive elements.Phylogenetic analysis showed that watermelon TLP proteins were classified into 10 evolutionary groups.The results of qRT-PCR showed that watermelon TLP genes were constitutive expression in all tested tissues and roots had higher levels than stems and leaves.Expression of majority of ClTLP genes could be up-regulated under Fusarium oxysporum infection and the highest expression level was observed after 120 h.Expression profiles of Cla97C01G019790 and Cla97C10G185250 were continuously up-regulated along with Fusarium oxysporum infection,while expression of Cla97C10G204510 and Cla97C10G185260 was significantly inhibited.【Conclusion】A total of 28 TLP members from the watermelon genome data were identified.The highest expression level was found in roots,and their expression could be up-regulated by Fusarium oxysporum.ClTLP could play important roles in pathogen responses of watermelon.