The Screening And Functional Studies Of Powdery Mildew Resistance Related Gene In Wheat SA/JA Signal Path

Wheat powdery mildew is one of the most serious diseases happened on common wheat leaves which is caused by white powdery mildew fungus (Blumeria graminisf. sp. tritici Bgt), and it occurs widely in China and other countries. From the stage of one leave to the aging, the whole plant can be invaded. According to the report, powdery mildew can cause13%～34%yield loss. However, too much depends on pesticide, not only increased the cost of production, but also caused extensive environmental pollution, which is a serious threat to agro-ecological security. Therefore, the use of biological techniques to clone high Powdery Mildew Resistance Genes and applied to wheat disease resistance genetics and breeding is the most economical, safe and effective method to control the epidemic of wheat powdery mildew.Salicylic acid (SA) pathway and Jasmonic acid (JA) pathway are two important signal ways in gene to gene resistance and inducible resistance mediated in plant. SA signal pathway and JA signal pathway coordinating interactions, check each other and regulate the resistance of plants to pathwayogen together in the disease resistance response.This study mainly from the influence of exogenous spraying SA/JA, to observe its impact on the resistance of plants to powdery midew, detection and analysis of the SA/JA pathway genes expression in resistant material and susceptible material after inoculate powdery mildew fungus, using the method of virus induced gene silencing (VIGS) screening the disease related genes and the further research and so on to do experiment, the experimental results obtained are as follows:1、Exogenous spraying SA/JA, can enhance the resistance of the Beijing837(susceptible material) to powdery mildew, and the role of JA more apparent.2、Screening of two powdery mildew resistance genes FAD (Ta-0109540) and HYP (Ta-1646165446) from20genes in the SA and JA signal pathway.3、Get the full-lenthgh TaFAD cDNA sequence, the sequence alignment found it is88%similarity with OsFAD2, and the similarity of AtFAD2is67%, determine its for TaFAD2; And found that TaFAD2expression level is basically unchanged in wheat after SA and JA trentment.4、By VIGS experiments we have found that:TaFAD2gene silence will make the original of resistance powdery mildew of wheat (PmA) local infection powdery mildew; Microscopic observation statistics, TaFAD2gene silence to enhance the powdery mildew fungus spores infection rate, phenotype and microscopic observation results show that TaFAD2gene involved in powdery mildew resistance response in wheat.5、In the VIGS plants of TaFAD2, the expression level of JA pathway genes obviously reduced, and SA pathway genes is the opposite, a slight increase. Proof TaFAD2gene is through positive control JA pathway, and negative adjust SA to participate in powdery mildew resistance.In short, the research of the SA and JA/ET signal pathwayways of powdery mildew resistance genetic screening and molecular mechanism is good to exploit new ways of the wheat disease-resistant, improve crop disease resistance, control disease prevalent and aim to contribute to the breeding of plants disease-resistant.