转Ta-UGT3基因增强了小麦对赤霉菌及其毒素DON的抗性
首发时间:2013-10-28
摘要:小麦赤霉病(Fusarium head blight,FHB)及其致病菌产生的主要毒素--脱氧雪腐镰刀菌烯醇(Deoxynivalenol,DON)不仅降低小麦产量,而且严重影响籽粒品质。DON还抑制真核生物细胞的蛋白质合成,被认为是赤霉病的致病因子。培育抗病品种是目前控制小麦中DON含量的最有效方法。前人的研究将一个小麦二磷酸尿核甘葡萄糖基转移酶基因(Ta-UGT3)在拟南芥体内的过量表达在一定程度上可以增强拟南芥幼苗对DON的耐受力。本研究将Ta-UGT3通过基因枪法转入高感赤霉病的小麦品种Alondra's,获得4个转Ta-UGT3基因阳性株系,并且目标基因能在穗部过量表达及在后代中稳定遗传。对4个T0代衍生株系的T1-T3代转化植株利用单花滴注法进行赤霉病抗性鉴定,结果显示其中T-26和T-92 2个株系T1-T3代阳性转基因植株平均病小穗率与受体对照Alondra's相比均有显著差异。根据病原菌侵染动态进展的分时期调查结果,和采用绿色荧光蛋白标记的赤霉菌株(HG)人工接种后进行穗部发病进程的显微观察结果,均表明Ta-UGT3主要是在病原菌扩展时期发挥作用。利用ELISA试剂盒进行籽粒DON含量的测定,结果发现上述2个转基因系DON含量显著低于受体对照,从而说明Ta-UGT3具有解除DON毒性的作用,从而提高了转基因小麦的赤霉病抗性。同时对T1-T3代转化植株主要农艺性状的调查和分析结果表明,与受体对照相比,转基因系的株高显著变矮,并且转基因系的分蘖数、小穗数和穗长比对照显著增加,这可能与Ta-UGT3介导的糖基化能够同时影响BR等植物激素有关。
关键词: 作物遗传育种 小麦二磷酸尿核甘葡萄糖基转移酶基因 赤霉病 脱氧雪腐镰刀菌烯醇 基因枪转化
For information in English, please click here
Transgenic wheat expressing a UDP-glucosyltransferase gene has enhanced resistance against Fusarium graminearum and the mycotoxin deoxynivalenol
Abstract:Wheat Fusarium head blight (FHB) caused by Fusarium graminearum is a destructive fungal disease in worldwide. FHB causes yield loss and contamination of grains with trichothecenes toxins such as deoxynivalenol (DON). It is proposed that DON acted first as a virulence factor during fungal pathogenesis and inhibits the biosynthesis of protein of eukaryote. Cultivated resisitant varieties are the most effective way to control the DON content in wheat. Previous studies showed that overexpression of the Ta-UGT3 gene in Arabidopsis could enhance tolerance against DON. In this study 4 transgenic lines that constitutively expressed Ta-UGT3 using a highly susceptible wheat variety Alongra's as receptor were developed, in which the target gene overexpressed in the spikes and stably inherited in the offspring. Single floret inoculation was used to identify the FHB-resistance of the 4 transgenic lines during T1-T3 generations, the proportion of scabby spikelets showed significant differences between transgenic lines T-26, T-92 and untransformed Alondra's. Observation of the dynamic process of F.g infection indicated that Ta-UGT3 may participate in resistance to FHB during the extension period of pathogens. The seeds DON content were determined using Enzyme-link Immunosorbent Assay (ELISA). Results showed that the DON content of T-26 and T-92 were significantly lower than control, indicating that Ta-UGT3 was able to dissolve DON, so then enhanced the resistance against Fusarium graminearum of the transgenic lines. Yet, the transgenic plants also displayed a dwarf phenotype and increase of tiller number, spike length and spikelet number, which reminiscent of brassinosteroid deficiency by the agronomical character investigation of T1-T3 transgenic lines, which possible due to the unwanted activity of UGTs such as the glycosylation of plant hormones.
Keywords: Crop genetics and breeding Wheat UDP-glycosyltransferase (TaUGT3) Fusarium head blight (FHB) deoxynivalenol (DON) particle bombardment transformation
论文图表:
引用
No.****
同行评议
共计0人参与
勘误表
转Ta-UGT3基因增强了小麦对赤霉菌及其毒素DON的抗性
评论
全部评论0/1000