Antagonistic Activity of spp. Against in Rhizosphere of Triggers the Expression of Host Defense Genes and Improves Its Growth Under Long-Term Monoculture System.

Under consecutive monoculture, the abundance of pathogenic fungi, such as in the rhizosphere of , negatively affects the yield and quality of the plant. Therefore, it is pertinent to explore the role of antagonistic fungi for the management of fungal pathogens such as Our PCR-denatured gradient gel electrophoresis (DGGE) results revealed that the diversity of spp. was significantly declined due to extended monoculture. Similarly, quantitative PCR analysis showed a decline in spp., whereas a significant increase was observed in . Furthermore, seven isolates from the rhizosphere were identified and evaluated for their potentiality to antagonize . The highest and lowest percentage of inhibition (PI) observed among these isolates were 47.91 and 16.67%, respectively. In assays, the treated with four isolates, having PI > 30%, was used to evaluate the biocontrol efficiency against in which ZC51 enhanced the growth of the plant without displaying any disease symptoms. Furthermore, the expression of eight defense-related genes of in response to a combination of and ZC51 treatment was checked, and most of these defense genes were found to be upregulated. In conclusion, this study reveals that the extended monoculture of could alter the communities in the plant rhizosphere leading to relatively low level of antagonistic microorganisms. However, ZC51 could inhibit the pathogenic and induce the expression of defense genes. Hence, ZC51 improves the plant resistance and reduces the growth inhibitory effect of consecutive monoculture problem.