A PHR-dependent reciprocal antagonistic interplay between UV response and P-deficiency adaptation in plants.

Plants are often simultaneously stressed by both UV radiation and phosphorus (P) deficiency in agricultural ecosystems. Coordinated responses and adaptations to these stressors are critical for plant growth, development, and survival. However, the underlying molecular response and adaptation mechanisms in plants remain elusive. Here, we show that plants use a reciprocal antagonistic strategy in response to UV radiation and P deficiency. UV radiation inhibited P-starvation response (PSR) processes and disrupted phosphate (Pi) homeostasis by suppressing the function of PHOSPHATE STARVATION RESPONSE PROTEINS (PHRs), the Pi central regulators. Conversely, P availability modulated the plant UV tolerance and the expression level of UV radiation response (URR) genes in a PHR-dependent manner. Therefore, reducing P supply or increasing PHRs activities can improve the tolerance to UV stress in rice. Moreover, this antagonistic interaction is conserved across various plant species. Furthermore, our meta-analysis showed that the increase in global UV radiation over the last forty years may reduce crop P-utilization efficiency worldwide. Our findings provide insights for optimizing P fertilizer management and breeding smart crops resilient to fluctuations in UV radiation and soil P levels.