Abstract:
In understanding of how a pathogen at Fusarium oxysporum cause dramatic changes at the biochemical levels of a host and how a curing actinomycetes as Streptomyces chibaensis is able to successfully induce defenses against the pathogen is the basis of the present work. Soil infestation with Fusarium oxysporum induced the prevalence of oxidative stress. This was generally underlain with an obvious decrease in activity levels of peroxidase, catalase and polyphenol oxidase in both roots and shoots. During the 1st and 2nd states of growth F. oxysporum evoked the accumulation of high level of phenols in roots of Lupinus termis with a concomitant decrease in shoots. The trend was reversed during the 3rd stage in root and shoot tissues. During 1st stage of growth as a result of soil inoculation with S. chibaensis culture, detoxifying enzymes (peroxidase, polyphenol oxidase) act synergistically. Considerable increase in enzymatic activity in shoots and roots compared to the control was recorded, while catalase enzyme behaved antagonistically. On the other hand, during 2nd and 3rd stages under the same treatment, peroxidase, catalase and polyphenol oxidase were all enhanced in plants root, shoot (except shoot polyphenol oxidase activity level). Shoots of L termis harvested from soil invested with S. chibaensis culture applied with F. oxysporum culture showed low levels in polyphenol oxidase activity, while the other two enzymes scored high levels. Generally, S. chibaensis tended to decrease the phenol content of both roots and shoots of L termis plants when added alone or with F. oxysporum either before or after it. Changes, in N K and Zn contents refer to their obvious decrease and increase in response to F. oxysporum and S. chibaensis, respectively, with a concomitant increase in Fe content in both cases. The protein banding pattern of leaves (55 DAS) refer to the over expression of new proteins having a role in both susceptibility of L termis to F. oxysporum (70, 50, 27 and 4.5 KD) and in resistance induced by S. chibaensis as those belong to the pathogen related proteins and the chitinases.
Page(s):
473-480
DOI:
DOI not available
Published:
Journal: International Journal of Agriculture and Biology, Volume: 5, Issue: 4, Year: 2003