Uncinula Necator Inoculation Induced Expression Profile Of Disease Resistance Related Genes In Grapevine

Powdery mildew of grapevine caused by Uncinula necator is one of the most important fungi diseases all over the world. Isolate powdery mildew resistance gene is of great value for resistance machinanism and resistant germplasm usage. With the material of Chinese wild grapevine specie Vitis pseudoreticulata cv Baihe 35-1, V. vinifera cv Carignane, and their resistant and susceptible F1 induvidual 6-12-4 and 6-12-2, the invasion procedure and inoculation induced gene expression profile at different invansion stage were analized to isolate and certificate the pathgensis related genes, therefore lay a valuable basis for resistant germplasm development and application. The results were as follows:The result of invansion procedure of Uncinula necator after inoculation were (1)The hyphae of Uncinula necator were found on the surface of resistant and susceptible grapevine after two weeks baging and under field conditions, the positive rate was lower in resistant plant than in susceptible one;(2)3 days after inoculation,the pathogen on the susceptible plant grow much quicker than that of resistant one, 3 day is the critical point for pathgensis; (3) The anatomic structure of infected leaves showed that the procedure of invasion was as follows: spore ger minated and formed germ tube after 1~3 days after inoculation, then an appressorium cell was formed at the end of germ tube, at last the new mycelium was formed from appressorium and penetrated through the epidermis and completed infection procedure.The gene expression analysis using Vitis vinifera microarray showed that:(1) More than 11000 probe sets on the microarray were positive in detecting the Chinese wild grapevie gene expression, more than 70 % of the total, implied the Vitis vinifera microarray can be used for Chinese wild grapevine gene expression dectetion;(2) Before inoculation, there is a significant difference between resistant and susceptible plant, genes present in R plant was much more than that of S plant, the up-regulated genes and the down-regulated genes were 871 and 954, respectively. In the down-regulated genes most of them had high fold of expression, encoding unknown and cell component genes, while in the down-regulated genes, most of them had low fold expresson, encoding molelare function; (3) 24 h after inoculation, genes present in R plant was much more than that of S plant,the up-regulated genes and the down-regulated genes were 526 and 796, respectively. In the down-regulated genes most of them had high fold of expression, encoding unknown genes, while in the up-regulated genes, most of them had low fold expresson, encoding cell component genes;(4) 48 h after inoculation, number of genes present in R plant (11839) was less than that of S plant (11906), the number of up-regulated genes and the down-regulated genes were 467 and 346, respectively. In the up-regulated genes most of them had high fold of expression, encoding molecular function genes, while in the down-regulated genes, most of them had low fold expresson, encoding biology process, cell component and unkown genes;(5) the number of differential expressed gene after 48 h was much more than that after 24 h in both resistant and susceptible plant; resistant plant had more up-regulated gene ratio than that of sensitive plant; but resistant plant had less down regulated gene ratio thant that of susceptible plant;(6) by the microarray analysis, the most up-regulated and down-regulated genes of before inoculation, 24 h after inoculation and 48 h after inoculation were listed out.