Activation of a calcium - dependent protein kinase involved in the Azospirillum growth promotion in rice
Rice seedlings (Oryza sativa) inoculated with the plant growth-promoting rhizobacteria Azospirillum brasilense FT326 showed an enhanced development of the root system 3 days after inoculation. Later on, a remarkable enlargement of shoots was also evident.
An increase in the Ca2 plus sign dependent histone kinase activity was also detected as a result of inoculation.
The biochemical characterization and Western blot analysis of the kinase strongly supports the hypothesis that it belongs to a member of the rice CDPK family.
The fact that the amount of the protein did not change upon inoculation seems to indicate that a posttranslational activation is responsible for the change in the enzymatic activity. An in-gel kinase experiment identified a 46 kDa CDPK like protein kinase as a putative component of the signal transduction pathway triggered by Azospirillum inoculation.
To our knowledge, this is the first report on the possible involvement of a Ca2 plus sign dependent protein kinase in promotion of rice plants growth by A. brasilense.
AZOSPIRILLUM RICE CDPK LATERAL ROOTS GROWTH PROMOTION