The potato (Solanum tuberosum L.) transcription factor StPHR1 responds to low phosphate stress and regulates phosphorus accumulation
TL;DR
Proteomic profiling showed that StPHR1-dependent Pi starvation responses involve metabolic reprogramming, membrane-lipid remodeling, redox homeostasis, and detoxification, and provide candidate targets and a molecular framework for improving low-Pi adaptation.
Abstract
Phosphorus is an essential macronutrient for plant growth and development. Potato is highly sensitive to inorganic phosphate (Pi) availability, yet the function and regulation of StPHR1, a putative core component of plant Pi signaling, remain poorly defined in this crop. Evolutionary analysis, subcellular localization assays, promoter activity analysis, CRISPR/Cas9-mediated gene editing, overexpression, and data-independent acquisition proteomics were used to characterize StPHR1. StPHR1 encoded a nuclear-localized MYB-CC transcription factor, whose promoter exhibits preferential activity in root tips and vascular tissues. Loss of StPHR1 function compromised low-Pi tolerance, reduced Pi accumulation in roots and leaves, and inhibited plant growth, whereas StPHR1 overexpression enhanced low-Pi tolerance and increased both tuber number and average tuber weight under conventional fertilized cultivation. Proteomic profiling showed that StPHR1-dependent Pi starvation responses involve metabolic reprogramming, membrane-lipid remodeling, redox homeostasis, and detoxification. These results identify StPHR1 as a key regulator of Pi accumulation and allocation in potato and provide candidate targets and a molecular framework for improving low-Pi adaptation.
