MITIGATION OF DROUGHT STRESS IN MAIZE THROUGH INOCULATION WITH DROUGHT TOLERANT ACC DEAMINASE CONTAINING PGPR UNDER AXENIC CONDITIONS

Drought is one of abiotic factors that hampers the growth and yield of crops via an elevated level of ethylene too, inspite of limited nutrients supply. The ACC deaminase containing PGPR can mitigate drought stress in crops by decreasing the synthesis and accumulation of ethylene. As maize is widely cultivated cereal and fodder crop, a glass jar study was conducted for screening of drought-tolerant ACC deaminase containing PGPR under axenic condition. Under various levels (i.e., 0, 10 and 20%) of polyethylene glycol (PEG) induced drought stress, some of the ACC deaminase containing PGPR significantly enhanced shoot and root length, shoot fresh and dry weight and root fresh and dry weight in maize seedlings. Further, a significant improvement in photosynthetic pigments formation and nutrients concentrations i.e., NPK in maize shoot validated the efficacious functioning of PGPR strains, Pseudomonas aeruginosa, Enterobacter cloacae, Achromobacter xylosoxidans and Leclercia adecarboxylata regarding reduction in ethylene accumulation in maize seedlings under drought. Pseudomonas aeruginosa, Enterobacter cloacae and Achromobacter xylosoxidans are previously documented but Leclercia adecarboxylata is a new drought tolerant ACC deaminase containing PGPR that might have the potential to alleviate drought stress by improving root elongation, NPK uptake and possibility decreasing ethylene in plants.