NITROGENASE ACTIVITY AND ENDOPHYTIC ESTABLISHMENT OF AZORHIZOBIUM CAULINODANS IN AUXIN INDUCED ROOT TUMORS OF RICEV.S.G.R. NaiduAbstract The treatment of rice seedling roots with synthetic auxins such as 2, 4-D (0.5 ppm), NAA (8 ppm) and IBA (8 ppm) resulted into the formation of nodule like structures (para-nodules). These para-nodules were readily colonized by Azorhizobium caulinodans which penetrated the para-nodule by migrating in between loosely arranged cells that covered their surface or by penetrating the space at the junction of root and paranodule (crack entry). Nitrogenase activity was enhanced in para-nodulated roots inoculated with A. caulinodans due to the increased internal bacterial colonization within the para-nodules, which provided the niche that protected the bacteria from the higher concentration of oxygen on the root surface.
Enter your contact information below to receive full paper.
|