Separation Of The Disease-resistant Related Gene To Head Smut Of Maize And The Discussion Of The Disease-resistant Reaction Mechanism

The maize head smut is caused by the invasion of Sporisorium reilianum f. sp. Zeae. In China, particularly in the spring maize producing areas, each year the loss is up to 300,000 tons due to this. For the increasing spread of the disease in recent years, more and more researches on head smut have been highlighted. We have studied clearly about the symptom performance of the head smut, the type of pathogenic fungus, infection circulation and the popular rule afer several generation pursuer's endeavor. But we know few about the disease-resistant mechanism of head smut, especially the enantiopathia respond involved in the signal conduction way and the correlation gene research are also very poor.In this study, SSH (Suppression Subtractive Hybridization) and cDNAmicro- array were used to identify genes which are sociated with resistance to head smut disease during the early stage of maize. Mo17 and Hz4 are two maize inbred lines with different resistance to the head smut. SSH libraries were constructed using cDNA samples from young plants. Both forward and reverse subtractions were performed for each inbred line. Consequently 68 positive clones induced by hypoxia were identified by differential screening. The treated and control message RNA were hybridized with the cDNA microarray of Mo17, sequentially, 76 of 2-fold differentially expressed clones were obtained. 144 positive clones were all sequenced. Bioinformatics analysis revealed that these positive clones represent 82 TUGs, including genes in several biochemistry pathways. We extrapolated some genes in the disease-resistant process to the vital role.Here we demonstrate a recent survey of the rate of infection of head smut by PCR. Using gene-specific primer derived from the head smut genomics and maize temporal and tissue-specific DNA, the invading process of the pathogen displays clearly. The study shows that the differential resistance of maize against head smut depends mainly on the ability of resistance against infection and spreading. Besides, the above effect disappears in the stamen when the tumor forms during tasseling stage.This research promulgates the massive information for further will study the head smut from now on the disease-resistant reaction mechanism and the disease-resistant response way have provided many valuable clues.