Towards a Functional Microbiome: Rhizospheric Microbe Abate Arsenic Uptake in Rice.

Rice (Oryza sativa L.) is the staple food for over half of the world’s population, but its quality and yield are impacted by arsenic (As) in some regions of the world.  To our knowledge, there is no transgenic or abiotic approach to lessen As uptake in rice.  Bacterial inoculants may be able to mitigate against the negative impacts in rice, and we identified a nonpathogenic, naturally occurring rice-rhizospheric bacterium that decreases As accumulation in rice roots in preliminary experiments. One Pantoea species strain (hereafter EA106) also demonstrated increased Fe-siderophore in culture. Our preliminary experiments showed EA106’s ability to impact rice growth in the presence of arsenic. These results show that both arsenic and iron concentrations in rice can be altered by inoculation with the rhizospheric microbe EA106. The results obtained will help in understanding the role of novel plant-microbial processes that are involved in enhancing plant fitness against As toxicity.