The Inhibition Activities of Isolates YD4-6, NV11-4 and Their Induced Activities to Rice Defense Enzyme

Abstract:

YD4-6 and NV11-4 strains were isolated from wheat soil and vegetable soil, both of them exhibited a better antifungal activities to several plant pathogens. The results exhibited that YD4-6 and NV11-4 showed antifungal activities to Rhizoctonia solani, Magnaporthe grisease, Sclerotinia sclerotiorum and Alternaria brassicae, while NV11-4 also can inhibit the growth of Fusarium moniliforme. Both of these two isolates exhibited without chitinase activity, NV11-4 with cellulase activities. Based on these differences to antifungal and cellulase activities of the YD4-6 and NV11-4, their effects on rice defense enzyme were observed. The results indicated that YD4-6 and NV11-4 effectively increased rice PPO, POD, PAL and SOD activities, also promoted concentration of MDA. When the R. solani used with isolates YD4-6, NV11-4, respectively, the induced activities of PPO, POD, PAL, SOD and concentration of MDA were higher than that of only used R. solani, YD4-6 or NV11-4. Compared with two antagonistic bacteria induced activities to rice defense enzyme, NV11-4 exhibited more durable than that of YD4-6, also YD4-6 induced accumulation of MDA, these difference maybe related with character of these two isolates. These two isolates were identified in database by using 16S rRNA sequence of YD4-6 or NV11-4. YD4-6 identified as Bacillus cerecus, and NV11-4 as Bacillus subtilis.