国家转基因生物新品种培育重大专项(2016ZX08002-001-004)
本研究从抗纹枯病小麦品种CI12633中克隆出一个小麦防御素基因TaPDF35,并对其表达特性及功能进行了分析。TaPDF35基因包含一个长为249bp的开放阅读框(Open Reading Frame,ORF),编码82个氨基酸组成的多肽TaPDF35。预测分析表明,TaPDF35能形成由一个 α螺旋和三股反向平行的β-折叠片组成的αβ(CSαβ)基序,αβ(CSαβ)基序由八个半胱氨酸形成的4个二硫键固定。TaPDF35的N端有一段27个氨基酸的信号肽。表达分析结果表明,TaPDF35基因在抗纹枯病小麦品种CI12633和山红麦中的表达量显著高于在感纹枯病小麦品种扬麦158和温麦6号中的表达量;该基因在小麦的叶鞘和茎中都有表达,且受纹枯病原菌(Rhizoctonia cerealis)诱导而上调表达。用大麦条形花叶病毒(Barley stripe mosaic virus,BSMV)诱导的基因沉默技术(Virus-induced gene silencing,VIGS),降低抗纹枯病小麦品种CI12633中TaPDF35基因的转录水平,再接种纹枯病原菌进行纹枯病抗性鉴定。结果显示,与接种BSMV:GFP的CI12633对照植株相比,TaPDF35表达水平降低的CI12633植株对纹枯病的抗性显著降低,表明TaPDF35表达是小麦防御纹枯病反应所需的。
In this study, a wheat defensin gene TaPDF35 was cloned from sharp eyespot-resistant wheat cultivar CI12633, and its expression and function were analyzed. TaPDF35 contains an open reading frame (ORF) with 249 bp-length, and encodes a peptide TaPDF35 consisting of 82 amino acid. The peptide TaPDF35 includes a signal peptide with 27 amino acid-length at its N-terminus. The mature protein forms a typical αβ (CSαβ) motif, which contains an α helix and a triple-stranded anti-parallel β-sheet and is stabilized through four disulfide bridges formed by eight cysteines. Real-time RT-PCR analysis showed that the expression levels of TaPDF35 gene in sharp eyespot-resistant wheat cultivars CI12633 and Shanhongmai were significantly higher than those in sharp eyespot-susceptible wheat cultivars Yangmai158 and Wenmai 6. The expression of TaPDF35 was up-regulated after infection of Rhizoctonia cerealis (the pathogen of sharp eyespot). Through BSMV-based virus-induced gene-silencing (VIGS) method, TaPDF35 silencing CI12633 plants induced by BSMV: TaPDF35 showed more susceptible to Rhizoctonia cerealis infection compared with CI12633 control plants induced by BSMV:GFP. The results suggest that the expression of TaPDF35 is required for wheat defense response to Rhizoctonia cerealis infection.
王敏霞,祝秀亮,罗美英,等.小麦防御素基因TaPDF35 的克隆与功能分析[J].植物遗传资源学报,2017,18(5):925-932.
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