BRADYRHIZOBIUM JAPONICUM IRAT FA3 INCREASES BIOMASS, YIELD AND DROUGHT TOLERANCE IN PLANTS

The effects of plant growth promoting rhizobacterium, Bradyrhizobium japonicum IRAT FA3 (PGPR) on non-leguminous model plants, maize (Zea mays) and Arabidopsis thaliana, were studied in this work for the first time. The impact of B. japonicum IRAT FA3 on plant growth development, biomass and yield were investigated using a nondestructive analytical method on root length and root hair formation, gene expression analysis of drought inducible transcripts and phenotypic characterization of plant response to drought stress under B. japonicum IRAT FA3 treatment. B. japonicumIRAT FA3 treated Arabidopsis plants showed a faster growth and development as well a higher biomass accumulation than non-treated plant. Maize plants developed longer roots with more root hairs and they looked healthier than non-treated plants. Drought inducible transcripts RD29A and Cor15A were higher in PGPR treated plants. PGPR treated plants withstood drought better and were more resilient after rehydration. Grain yield increased by approximately 1600% in B. japonicum treated plants. Our data demonstrate for the first time that B. japonicum IRAT FA3 treatment increases yield, biomass and primes non-leguminous plants for drought stress, suggesting that this strain of B. japonicum can be used as growth promoting rhizobacterium for a wide range of leguminous and non-leguminous crops for agricultural sustainability.