Plant growth-promoting actinobacteria on chickpea seed mineral density: an upcoming complementary tool for sustainable biofortification strategy

The present study was evaluated to test the potential of plant growth-promoting actinobacteria in increasing seed mineral density of chickpea under field conditions. Among the 19 isolates of actinobacteria tested, significant (p < 0.05) increase of minerals over the uninoculated control treatments was noticed on all the isolates for Fe (10-38 %), 17 for Zn (13-30 %), 16 for Ca (14-26 %), 9 for Cu (11-54 %) and 10 for Mn (18-35 %) and Mg (14-21 %). The increase might be due to the production of siderophore-producing capacity of the tested actinobacteria, which was confirmed in our previous studies by q-RT PCR on siderophore genes expressing up to 1.4-to 25-fold increased relative transcription levels. The chickpea seeds were subjected to processing to increase the mineral availability during consumption. The processed seeds were found to meet the recommended daily intake of FDA by 24-28 % for Fe, 25-28 % for Zn, 28-35 % for Cu, 12-14 % for Ca, 160-167 % for Mn and 34-37 % for Mg. It is suggested that the microbial inoculum can serve as a complementary sustainable tool for the existing biofortification strategies and substantially reduce the chemical fertilizer inputs.