Nutrient use efficiency promoted hormonal crosstalk and stomatal dynamics in wheat under the co-impact of arsenic and drought.

This study presents the interlink of Nutrient use efficiency (NUE) influenced hormone and stomatal dynamics, in enhancing photosynthesis under the co-impact of drought (D) and arsenic (As) in wheat. We analyzed how nitrogen (N) and phosphorus (P) supplementation under D+As modulates these interactions with jasmonic acid (JA) and sucrose, as central regulators. Enhanced JA by NP-enrichment reduced abscisic-acid (ABA) and salicylic-acid (SA) production to promote stomatal opening via sugar-transporter-proteins; TaSTP12, TaSTP51, and TaKAT-like1. Computational docking confirms strong interaction between JA, TaMYB84 and TaSTP's (TaSTP12, TaSTP51) suggesting a functional complex that facilitates sucrose osmoregulation. This influences stomatal opening which promotes gas-exchange for better photosynthesis. Additionally, we highlight the correlation between stomatal dynamics and NP-use efficiency. The NP-promoted photosynthesis, phosphorus-use efficiency (PnPUE), and TaPHT1. 10 ensures Pi availability for Krebs-cycle. This improves non-photochemical quenching (NPQ), for ATP production, boosting CO assimilation. Moreover, the increased photosynthetic-nitrogen-use efficiency (PnNUE), along with TaNRT2.1, and TaAMT1.1 augmented rubisco activity, thereby increasing photosynthesis. NP-supplementation also boosts ASC-GSH cycle, which safeguards the rubisco enzyme and light-harvesting-complex. These processes optimize photosynthesis to maintain starch reserves and sustain wheat productivity under D+As. Our findings provide valuable insights into NP-mediated photosynthetic regulation and underscore the crucial role of NUE in optimizing this process.