Symbiotic interplay of Piriformospora indica and Azotobacter chroococcum augments crop productivity and biofortification of Zinc and Iron.

In the present study Piriformospora indica (Pi) a phyto-promotional fungus and Azotobacter chroococcumWR5 (AzWR5) a rhizobacterium, were symbiotically evaluated for their role in improving the nutritional quality of wheat (Triticum aestivum L.). Co-inoculation of Pi+AzWR5 modified root system architecture of host and along with increasing the proportion of finer roots by 88% and 92% in C306 and Hd2967 respectively. Furthermore, the synergistic impact of Pi+AzWR5 interplayed for enhanced accumulation of Zn and Fe in different plant parts including grains (3.12 and 1.33 fold respectively). Pi+AzWR5 increased the transfer factor of Zn (62%, 94%, 91% and 213%) and Fe (31%, 54%, 68% and 32%) in root, stem, leaves and grains, respectively, and translocation factor of Zn (20%, 18% and 63%) and Fe (18%, 29% and 29%) for root-stem, root-leaves and root-grains, respectively. In addition to these co-inoculation of endophytes led to several fold increase in expression of four ZIP transporter genes in roots and shoot. In addition to these symbiotic association of endophytes with host led to 3 fold increase in grain yield. We thereby conclude that co-inoculation of Pi+AzWR5 substantially improves mobilization of Zn and Fe from soil and increase its concentration in grains as well as improves crop yield.