Studies On Pathogenic Characteristic Of Bipolaris Maydis Race C And Effects Of HMC Toxin On Microfilaments Disturbution

Southern blight of corn was a king of universal fungal plant disease at the present.During infecting corn seedings, the pathogen of Bipolaris maydis race C could produce an active metabolic production, namely pathogenic toxin (HMC-Toxin). We studied the pathogenic characteristic of Bipolaris maydis race C on pathogenicity restoration, on the relation between Ca2+ signal pathway and conidium germination and appressorium formation, on the relation between the production and cultural condition of HMC toxin, the effect of HMC toxin on protoplasts of Charrua cytoplasmic male-sterile maize. The results showed that Bipolaris maydis race C might improve spores production and pathogenicity by culturing on PDA medium with fresh leaves constantly; that Ca2+signal pathway involved in conidium germination and appressorium formation of Bipolaris maydis race C; that motionless and darkness were more advantageous than the shaking and light in the output of toxin; and that HMC toxin was specifically harmful to the protoplasts of Charrua cytoplasmic male-sterile (cms) maize.Microfilaments was an important component of cytoskeleton, which took part in many biological processes. The research was engaged in the effect of HMC toxin on microfilaments of N and C cytoplasmic male-sterile maize by fluorescence technique and confocal scanning microscopy. Some new results were as following: that 80Mg/ml HMC toxin made actin filaments(AFs) distribution of cms-C maize completely depolymerized, and that of homokaryotic maintainer line(N) were normal. There were apparently similar effects between the HMC-toxins and cytochalasin B on the distribution of AFs. The results raised the possibility of high correlation between the responds of two kinds of detached root cap cells to HMC-toxin and their disease resistance.