Analysis Of The Different Gene Expression Induced By Fusarium Graminearum And The Secretory Proteins From Fusarium Graminearum

Fusarium head blight (FHB), caused by the facultative pathogen Fusarium spp., is a serious disease in wheat (Triticum aestivum L.) and received significant attention because of the fact that it causes economic losses due to reduction in both yield and quality. Although there are many reports about the wheat response to F. graminearum infection, there is a limited understanding of the molecular mechanism involved in plant resistance against the infection of F. graminearum. This study includes two aspects: (1) We performed a systematic genome-wide transcriptional profiling analysis among wheat spikelets from the FHB near-isogenic lines, Apogee/Apogee73S2, respectively, in normalized or inoculated with F. graminearum, using the Solexa technology. (2) The expressed secretome of F. graminearum was analyzed by using shotgun proteomics. The results are as follows:(1)2571 genes were up-regulated and 3620 genes were down-regulated following F. graminearum infection of the resistant line Apogee73S2 that was inoculated with F. graminearum and with water, respectively. The differentially expressed genes were mainly involved in metabolic pathways, biosynthesis of plant hormones, biosynthesis of phenylpropanoids, biosynthesis of alkaloids derived from shikimate pathway and other processes. 2004 genes and 2192 genes were down-regulated and up-regulated respectively in the combination with Apogee73S2 and Apogee inoculated with F. graminearum . The processes that the different expression genes participated in are the same as the different expression genes between the above combinations. The results suggest that the different expression of genes involved in plant hormone biosynthesis and secondary metabolism might play a critical role in the resistance against the infection of F. graminearum.(2)A total of 63 secreted proteins of F. graminearum have been experimentally verified including the proteins with the functions in protein hydrolysis, carbohydrate hydrolysis, lipase hydrolysis, lignin degradation, chitosan degradation, toxin synthesis, second metabolite process. Some of proteins were possible virulence factors. 25 proteins participated in the degradation of plant cell wall, and 6 proteins were included in the synthesis of virulence. These results indicate that the degradation of plant cell wall was important during the Fusarium granminearum infection and made the fact that the virulence factors possible. And there were 56 classical secretory proteins, while 7 non-classical secretory proteins.