Proteome analyses of low phosphorus responses in Stylosanthes guianensis roots

Stylosanthes guianensis (stylo) is a pioneer tropical legume with great potential for low phosphorus (P) tolerance. In this study, a P-efficient stylo genotype was used to investigate the protein profiles response to P deficiency through a label-free proteomic approach. A total of 3387 proteins were identified in roots under two P (high or low P) treatments. Proteins with significant changes in abundance (P < 0.05) by more than two-fold were considered as differentially expressed proteins (DEPs). Results showed that 415 proteins displayed differentially expressed under two P treatments, which accounted for 12.3% of the total proteins. These DEPs included 168 up-regulated proteins, which consisted of 117 increased and 51 induced proteins, and 247 down-regulated proteins, including 101 decreased and 146 suppressed proteins. A total of 38 phosphoesterases were identified in stylo roots and could be divided into five categories, such as phosphatase, phosphodiesterase,