Isolation Of Genes Expressed During Compatible Interactions Between Powdery Mildew (Blumeria Graminis) And Wheat

Powdery mildew of wheat is one of the most important disease caused by theobligate biotrophic fungus Blumeria graminis f.sp.tritici. In order to illustrate themachunism of compatibility between powdery mildew and wheat, wheat-powderymildew interaction was used to identify the host compatibility factors.The cultivar of wheat yang158 responds with HR-resistance to powdery mildewisolate Qiul and susceptible to isolate Bai3. Infected leaves postinoculated with Bai3,Qiul at 5d and uninoculated leaves were collected for cDNA-AFLP analysis. 223differential cDNA fragments in susceptible leaves were screened, 75％of which could bereamplificated. Of these transcript derived fragments, 85 were sequenced, 41 showedhomology to sequence with kown function. Among 41 fragments, 26 fragments showedhigh homology (E＞1e-03). The genes coding Chloroplast hypothetical protein, Putativeflower development regulator, LEUNI protein, Ethylene-responsive proteinase inhibitor 1precursor, Clone wlm96.pk028.k4:fis, full insert mRNA, Putative ROP6 protein, Glycosyltransferase, group 1, Putative phytase, Chloroplast ribosomal protein S8, Elongationfactor 1 gamma-like protein, mRNA, Gigantea 3, patatin-like protein were analyzed byRT-PCR. The result showed two genes coding Putative flower development regulator,LEUNI protein and Putative phytase were not correlated to susceptibility of wheat topowdery mildew, the other ten genes were differentially expressed. The genes codingEthylene-responsive proteinase inhibitor 1 precursor and Clone wlm96.pk028.k4:fis, fullinsert mRNA only expressed in both susceptible and resistant leaves, but expressed morestrongly in susceptible leaves with a peak at 5d. The genes coding Putative ROP6 protein,Elongation factor 1 gamma-like protein, Triticum aestivum, mRNA, Gigantea 3 andPatatin-like protein only expressed in susceptible leaves, of which, the genes codingPutative ROP6 protein, Elongation factor 1 gamma-like protein and Patatin-like proteinexpressed at 1 d, 2d, 5d and 7d after inoculation with a peak at 5d; the gene codingGigantea 3 only expressed at 5d and 7d, but the transcript accumulation at 5d is more; thegene coding Triticum aestivum, mRNA only expressed at 5d. These five genes that onlyexpressed in susceptible leaves maybe related to susceptibility of wheat to powderymildew fungus. The genes coding Ethylene-responsive proteinase inhibitor 1 precursor,Clone wlm96.pk028.k4:fis, full insert mRNA, Putative ROP6 protein, Triticum aestivum, mRNA, Gigantea 3 and Patatin-like protein were analyzed by Northern blot. The resultwas consistent with RT-PCR. In this study, the genes correlated to susceptibility of wheatto powdery mildew were screening primarily, which participated in nutrition acquisition,defence suspression and inhibition of programmed cell death. This research establishedbasic information for understanding molecular mechanism of defence suppression andnutrition acquisition of obligate biotrophic pathogens to plant.