Application of virus-induced gene silencing for identification of FHB resistant genes

Virus-induced gene silencing (VIGS) showed several advantages to identify gene functions such as short experimental cycle, more broad hosts, etc. In this study, the feasibility and efficiency of employing Barley stripe mosaic virus (BSMV)- based VIGS system to evaluate Fusarium head blight (FHB) resistance were explored in wheat. With variable conditions tested, it showed that the maximal silencing efficiency 78% on spike was obtained when the recombinant BSMV was inoculated on flag leaf at flagging stage. However, the plant may reduce its own immunity to FHB when inoculated with BSMV. To induce this impact, different Fusarium graminearum strains were tested and SF06-1 strain was selected for FHB resistance evaluation. Using this system, TaAOC, TaAOS, and TaOPR3 involved in jasmonic acid (JA) signaling pathway were identified to positively regulate FHB resistance, which was underpinned by the results when silencing TaAOS in wheat by stable transgenic plants.

转录因子基因TuGTγ-3参与乌拉尔图小麦对条锈病的抗性

小麦条锈病是由条形柄锈菌小麦专化型（PucciniastriiformisWest．fsp．triticiEriks．＆Henn．，Pst）引起的一种严重的真菌病害，发掘新的抗条锈病相关基因对于小麦抗病育种和抗病机理研究都具有重要意义。Trihelix是植物特有的转录因子家族，参与调控生长发育、形态建成、胁迫应答等过程。迄今，小麦属Trihelix家族与抗条锈病相关的研究尚未见报道。本研究从乌拉尔图小麦（TriticumurartuTurn．，2n=2x=14，AA）中克隆了Trihelix家族GTy亚家族中的一个基因，命名为TuG71y-3。序列分析表明，TuGTy-3基因具有完整的开放阅读框（ORF），编码序列（CDS）全长1329bp，编码442个氨基酸，推测其编码蛋白的分子量为50-31kDa，理论等电点为6.12。生物信息学预测TuGT7-3蛋白有一个单分型核定位信号（GLPMQKKMRYT），没有信号肽和跨膜结构域。TuGTy-3蛋白的保守trihelix结构域的氨基酸序列位置为Q115-R187，第四a-螺旋位置为F234-Y241，cc结构域的位置为K362-K436,二级结构分析显示，TuGTy-3蛋白由43．89％的a-螺旋、9．51％的伸展链、9．95％的β-转角和36．65％的不规则卷曲构成。利用普通小麦的基因组数据库BLAST分析表明，TuGTy-3被定位于5A染色体长臂上。瞬时表达实验显示，TuGTY-3蛋白主要定位在细胞核中，但细胞质中也有少量分布。表达谱分析表明，TuGTy-3基因在叶片中的表达量显著高于根和叶鞘，且受小麦条锈菌小种CYR32的诱导而强烈上调表达。进一步通过大麦条纹花叶病毒诱导的基因沉默（BSMV-VIGS）实验证明，转录因子TuGT7—3正向调控了乌拉尔图小麦对条锈病的抗性。