Phosphate Starvation Primes Plant Immunity through an ABA-OsbZIP12-Phytoalexin Signaling Network
Yuqing He1, Jitao Hu2, Li Jiang3
1State Key Laboratory for Quality and Safety of Agro - Products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, P. R. China, Hangzhou, 310021; Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, P. R. China, Hangzhou, 310021.
Abstract:
Phosphate (Pi) starvation is a major constraint on crop productivity, yet its impact on disease resistance is poorly understood. Abscisic acid (ABA) is central to abiotic stress responses, but its interplay with nutritional cues and immunity remains elusive. Here, we reveal how Pi starvation enhances rice blast resistance through a complex ABA-mediated signaling network. We found that Pi-starvation rice exhibits elevated ABA, increased accumulation of the phytoalexin sakuranetin (SAK), and enhanced resistance to Magnaporthe oryzae. Strikingly, ABA exerts a biphasic effect on immunity: brief, high-concentration exposure suppresses resistance, while sustained, low-level treatment promotes it by differentially regulating SAK biosynthesis and endogenous ABA homeostasis. We identified the transcription factor OsbZIP12 as the central integrator of these signals. OsbZIP12 directly activates the SAK biosynthesis gene OsNOMT and is itself regulated by distinct inputs from both Pi starvation (ABA-independent) and ABA signaling. Genetic analyses confirmed that OsbZIP12 is essential for this SAK-dependent resistance. Our findings establish a novel Pi-ABA-immunity network orchestrated by OsbZIP12, providing molecular targets for strategies that leverage nutritional stress to enhance crop resilience.
Related Concept Videos
Cell Signaling in Plants
Defenses Against Pathogens and Herbivores
Microbe-Plant Interactions
Introduction to Plant Diversity
Responses to Salt Stress
Gene Regulation During Sporulation


