Investigation on Histological observation and protective enzyme activities in ear rot of maize (Zea mays L.) after Fusarium moniliforme infection

Journal: Acta Phytopathol Sinica.2011,4: 385-392

Author: Yuan GS, Zhao MJ, Zhang ZM, Shen YO, Pan GT

Abstract:

To further investigate the processes involved in maize ear rot upon infection by the fungus Fusarium moniliforme (FM), the time-course infection was observed through scanning electron microscope (SEM) to demonstrate pathogen progression in maize bract, then the biochemical and physiological enzyme activities were analyzed in the two maize cultivars, Bt-1 and Ye478, completely resistant and significantly susceptible to FM respectively. Microscopic observations showed that FM produced hyphae development first and then penetrated host tissues through the stoma at approximately 72 h postinoculation (hpi). Meanwhile, the phenylalanine ammonialyases (PAL) and the reactive oxygen species (ROS) such as peroxidase (POD) were increased promptly higher and faster in Ye478, comparing to that in resistant cultivar Bt1. The content of malondialdehyde (MDA) was higher in Bt1than Ye478. Finally, the patterns of POD isozyme changed dramatically and increased three or four bands in both cultivars after infection. The results imply that the relationship between protective enzymes activity and resistant cultivars are negatively correlated, while there was a positive correlation between the content of MDA and resistance of the cultivars. Overall, the response to protective enzyme activities and histological observation might provide important bases to probe the resistant mechanisms, the alteration of metabolism and the breeding research upon the infection of FM in maize.

Link: http://zwblxb.cau.edu.cn/CN/abstract/abstract40.shtml