Effects of phosphorus deficiency on lipid composition and photosynthesis process in Zygophyllum xanthoxylum

Under phosphate (Pi) limiting conditions, lipid remodeling serves as a critical mechanism for enhancing phosphorus (P) use efficiency in plants. This process also affects the photosynthetic process simultaneously, thereby influencing the accumulation of biomass. Our previous studies have proved that Zygophyllum xanthoxylum had a remarkable P remobilization capacity, and could maintain a high biomass under Pi deficiency environment. However, the specific patterns of membrane lipid remodeling and their regulatory effects on photosynthetic performance remain to be elucidated. In this study, the changes of photosynthetic parameters, chlorophyll fluorescence parameters, leaves lipid compositions, Pi content and ATPase activity of chloroplast were determined after 1D, 10D and 40D of Pi sufficient and Pi deficient treatments. We found that Pi deficiency did not cause a significant decrease in photosynthetic indices (except 40D treatment) and did not weaken the photosynthetic electron transport process. Under Pi deficiency treatment, the glyceroglycolipid content in leaves showed significant increase at 10D and 40D treatments, but the phospholipid content remained stable. The concentration of Pi and the activity of ATPase in chloroplasts at 1D and 10D treatments were significantly increased, but there was no significant difference between 40D treatment and that of the CP. The results showed that under Pi deficiency environment, Z. xanthoxylum provided structural and functional protection for electron transport process by maintaining the content stability of phospholipids and increasing the glyceroglycolipid content. In addition, more Pi was allocated to chloroplasts, enhancing ATPase activity and providing continuous and stable assimilatory power for the photosynthetic process.