Genetic Engineering of glucose utilization in a plant associated bacterium leads to improved root colonization and shoot biomass

Varanasi : Plant growth promoting bacteria live in the root zone of several crops and promote their growth by producing auxin-like hormones which help in developing a robust root system of the plant. But, these bacteria can grow and multiply in the root zone only if they are able to utilize carbon compounds secreted by the plant roots. Azospirillum brasilense Sp7 is very popular and frequently used biofertilizer for several agriculturally important crops but it is not able to multiply itself in the root zone of rice due to its inability to efficiently utilize glucose, which is secreted by rice roots. Dr Vijay Shankar Singh, a CSIR Senior Research Associate and Mr Sushant Rai, Senior Research Fellow under the supervision of Prof Anil Kumar Tripathi, School of Biotechnology, Institute of Science have been successful in genetically engineering glucose utilization capability in Azospirillum brasilense. The engineered strain of Azospirillum brasilense was able to multiply itself in the root zone due to its newly acquired ability to utilize glucose. Inoculation of the engineered strain caused about 30-40 % increase in the shoot biomass of rice seedlings. This work is part of a project funded by Indian Council of Agricultural Research (ICAR) and has recently been published in the prestigious journal “Applied Microbiology and Biotechnology” (Springer Nature).