Identification of phosphorus stress related proteins in the seedlings of Dongxiang wild rice (Oryza rufipogon Griff.) using label-free quantitative proteomic analysis

Abstract Background: The lack of available phosphorus (P) in soil is one of the important factors restricting rice growth. Previous studies indicated that Dongxiang wild rice (DXWR, O. rufipogon Griff.) was resistant to low-P stress. So far, the research of resistance mechanism in DXWR was very limited.Results: The results showed that 3589 significant differential accumulation proteins were identified between low P and the normal P treated root samples. 60 up-regulated and 15 down-regulated proteins were identified with ≥ 1.5-fold changes as an additional standard. Furthermore, among 75 significantly different expression proteins (SDEPs), 24 proteins also detected in previous transcriptome dataset verified by qRT-PCR, including OsPT2, OsPT8, OsPAP10c, OsPAP10a and OsPHF1. Through comprehensive analysis, it was found that DXWR could increase PAPs, membrane location of PTs, rhizosphere area, alternative splicing and decrease ROS activity to deal with low-P stress. Moreover, among the genes corresponding to 75 SDEPs, 7 uncharacterized genes were located in previous P related QTL intervals, of which two genes (LOC_Os12g09620 and LOC_Os03g40670) have been detected at both transcriptome and proteome levels. In addition, the expression patterns of OsPHR1, OsPHR2, OsPHO1 and NAT-OsPHO1 in DXWR were different in cultivated rice, suggesting that the response mechanism of some low-P tolerance in DXWR might be different from that in cultivated rice.Conclusions: This study screened out some candidate genes for low-P resistance and preliminarily verified that there might be a different low-P response mechanism in DXWR than in cultivated rice, which would provide insights in cloning the P-deficiency genes from wild rice, as well as elucidating the molecular mechanism of low-P resistance in DXWR.