Proteome-wide lysine acetylation profiling provides insights into the involvement of acetylation in the phosphate starvation response of Chinese fir roots

Phosphorus is a crucial yet frequently limiting nutrient in forest ecosystems, particularly in rapidly growing coniferous plantations within subtropical red soil regions. Phosphorus deficiency adversely affects soil fertility and productivity, presenting a significant challenge for Chinese fir ( Cunninghamia lanceolata ) plantations. Despite its importance, the impact of phosphorus limitation on Chinese fir roots and the role of acetylation modifications in regulating these responses are not well understood. This study investigates the morphological and physiological effects of varying phosphorus levels on Chinese fir roots, with a focus on acetylation modifications of proteins and their regulatory functions. Our results reveal that phosphate starvation leads to significant increases in root growth rate and cell size. Physiological assessments show that under phosphorus starvation, starch, sucrose and acid phosphatase fall, while oxalic, malic, citric, succinic, tartaric and maleic acids fluctuate variably over time. Through comprehensive acetylome analysis, we identified 201 acetylation sites on 185 proteins. Further analysis through acetylation and Parallel Reaction Monitoring (PRM) techniques indicated that phosphate starvation regulates the acetylation levels of ACO, LSC, and ACLY in the TCA cycle, PFP, ENO, and HK in Glycolysis/Gluconeogenesis, as well as SnRK2, PYR/PYL, and MPK6 in the ABA metabolic pathway. These findings highlight the essential role of acetylation in modulating the adaptability of Chinese fir roots to phosphorus deficiency through influence on multiple metabolic pathways and insights into the function of acetylation modifications in plant phosphorus metabolism. • First proteome-wide lysine acetylation profiling in Chinese fir roots under phosphate starvation, revealing 201 acetylation sites. • Phosphorus deficiency induces root morphological remodeling (increased length/surface area) and dynamic organic acid secretion. • Key acetylated enzymes such as ACO, LSC, PFP, SnRK2, and PYR/PYL were identified as central regulators of phosphorus deficiency adaptation. • Acetylation-mediated metabolic reprogramming offers novel insights into post-translational regulation of nutrient stress responses.