Underpinning wheat physiological and molecular responses to co-occurring iron and phosphate deficiency stress

Iron (Fe) and phosphate (P) are essential mineral nutrients for plant growth and development. While it is known that Fe and P pathways interacts within plants however, our understanding of the molecular mechanisms regulating nutrient interaction during plant vegetative and reproductive stages remains largely unknown. Herein, we provide a comprehensive physiological and molecular analysis of hexaploid wheat response to single P/Fe and combined Fe and P deficiency. Our data showed that wheat primary root growth was inhibited in response to -Fe, and remarkably rescued by co-occurring deficiencies of Fe and P. Transcriptome analysis revealed drastic and distinct molecular rearrangements to adapt the single and combined nutrient stress with dominance of Fe responsive cis-regulatory elements. Gene-based clustering and root-specific transcriptome expression analysis identify several important unique components induced in response to combined stress -Fe-P, including UDP-glycosyltransferases and cytochrome-P450 and glutathione metabolism. These data are consistent with our metabolome data, which further reveals specific metabolite accumulation in -Fe-P those include amino-isobutyric acid, arabinonic acid and aconitic acid. Finally, at reproductive stage alleviations of the negative effect of Fe was also observed in -Fe-P (i.e. spikelet and grain development). Collectively, the data obtained is essential for designing new strategies to improve resilience of crops to cope with the limited nutrients in soils.