茉莉酸甲酯诱导的小麦白粉病抗性与9个抗病相关基因表达间的关系

[目的]为了明确茉莉酸对小麦白粉病抗性的诱导作用和对抗病相关基因的激活作用,以及抗病性变化与基因表达变化之间的相关性,探索小麦抗白粉病分子机理。[方法]以田间表现不同的代表性感白粉病小麦品种＂中国春＂、＂濮麦9号＂和＂周麦18＂为材料,用茉莉酸甲酯（methyljasmonate,MeJA）处理小麦幼苗叶片进行诱导,通过离体叶段培养法接种白粉菌（Blumeria graminis f.sp.tritici,Bgt）进行抗性鉴定;用实时定量PCR技术检测叶片中PR1（PR1.1）、PR2（β,1-3葡聚糖苷酶）、PR3（几丁质酶）、PR4、PR5（类甜蛋白）、PR9（TaPERO,过氧化物酶）、PR10、TaGLP2a（类胚素蛋白）和Ta-JA2（茉莉酸甲酯诱导蛋白）基因的表达变化。[结果]MeJA处理可以显著提高＂中国春＂、＂濮麦9号＂和＂周麦18＂对白粉菌的抗性水平。诱导抗性可以从MeJA处理后12～96h检测到,24h达到峰值。虽然存在一定差异,但MeJA对3个品种中除TaGLP2a外的8个抗病相关基因的表达有显著激活作用,在处理12、24或48h后达到峰值。MeJA对PR9和PR1的诱导作用最强,可达100倍,对PR2、PR4、PR5、PR3、PR10和Ta-JA2的诱导作用强,可达10-70倍;对TaGLP2a没有明显作用。茉莉酸诱导的抗病性提高与8个抗病相关基因的表达增强呈正相关。[结论]茉莉酸诱导的抗病性增强与抗病相关基因的表达增强呈正相关,茉莉酸信号传导途径在小麦抗白粉病反应中起作用,对这一途径的调控可提高小麦的白粉病抗性。

The Relationship of Methyl Jasmonate Enhanced Powdery Mildew Resistance in Wheat and the Expressions of 9 Disease Resistance Related Genes

[Objective] This study was carried out to determine the induction effect of jasmonic acid(JA)on powdery mildew resistance in wheat,the activation effect on the expressions of plant disease resistance related genes,and to investigate the relationship between the induced resistance and the gene expression patterns.[Method] Three powdery mildew susceptible cultivars of "Chinese Spring","Pumai 9" and "Zhoumai 18" typically representing different phenotypes in the field were employed.The powdery mildew was assessed by detached leaf assay,and real time quantitative RT-PCR was used to determine the expression patterns of 9 disease resistance related genes of PR1(PR1.1),PR2(β,1-3 glucanase),PR3(chitinase),PR4(wheatwin1),PR5(thaumatin-like protein),PR9(TaPERO,peroxidase),PR10,TaGLP2a(germin-like)and Ta-JA2(jasmonate-induced protein)in leaf of the three cultivars.[Result] MeJA application enhanced the powdery mildew resistances of "Chinese Spring","Pumai 9" and "Zhoumai 18".The induced powdery mildew resistance could be detected from 12 h to 96 h after MeJA treatment,and the peak value was at 24 h.Though there were differences between the three cultivars,MeJA significantly effect on the expressions of the 8 disease resistance related genes except TaGLP2a,and the peak values were at 12 h,24 h or 48 h after treatments.The strongest activation of MeJA was on PR9 and PR1 that their expressions could reach more than 100 times of the untreated samples.MeJA strongly activated PR2、PR4、PR5、PR3、PR10 and Ta-JA2,their expression could reach 10 to 70 times,and there was almost no activation effect on TaGLP2a.The induced powdery mildew resistance positively correlated with the induced expressions of the 8 disease related genes.[Conclusion] The induced powdery mildew resistance positively correlated with the induced expressions of the disease related genes.Jasmonate signalling plays a role in defence against Blumeria graminis f.sp.tritici.and future manipulation of this pathway may improve powdery mildew resistance in wheat.