Serendipita besciipromotes winter wheat growth and modulates the host root transcriptome under phosphorus and nitrogen starvation

Serendipita vermiferassp.bescii, hereafter referred to asS. bescii, is a root-associated fungus that promotes plant growth in both its native switchgrass host and a variety of monocots and dicots. Winter wheat (Triticum aestivumL.), a dual-purpose crop, used for both forage and grain production, significantly contributes to the agricultural economies of the Southern Great Plains, USA. In this study, we investigated the influence ofS. besciion growth and transcriptome regulation of nitrogen (N) and phosphorus (P) metabolism in winter wheat.Serendipita besciisignificantly improved lateral root growth and forage biomass under a limited N or P regime. Further,S. besciiactivated sets of host genes regulating N and P starvation responses. These genes include, root-specific auxin transport, strigolactone and gibberellin biosynthesis, degradation of phospholipids and biosynthesis of glycerolipid, downregulation of ammonium transport and nitrate assimilation, restriction of protein degradation by autophagy and subsequent N remobilization. All these genes are hypothesized to regulate acquisition, assimilation and remobilization of N and P. Based on transcriptional level gene regulation and physiological responses to N or P limitation, we suggestS. besciiplays a critical role in modulating stress imposed by limitation of these two critical nutrients in winter wheat.

Automated summary

The root-associated fungus Serendipita bescii significantly improves lateral root growth and forage biomass in winter wheat under limited nitrogen or phosphorus conditions, activating a set of host genes regulating nitrogen and phosphorus starvation responses. These genes are hypothesized to regulate the acquisition, assimilation, and remobilization of nitrogen and phosphorus. The study suggests that S. bescii plays a critical role in modulating stress imposed by nitrogen and phosphorus limitation in winter wheat.