A comprehensive quantitative phosphoproteome analysis of rice in response to bacterial blight

Abstract

BackgroundRice is a major crop worldwide. Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) has become one of the most devastating diseases for rice. It has been clear that phosphorylation plays essential roles in plant disease resistance. However, the role of phosphorylation is poorly understood in rice-Xoo system. Here, we report the first study on large scale enrichment of phosphopeptides and identification of phosphosites in rice before and 24 h after Xoo infection.ResultsWe have successfully identified 2367 and 2223 phosphosites on 1334 and 1297 representative proteins in 0 h and 24 h after Xoo infection, respectively. A total of 762 differentially phosphorylated proteins, including transcription factors, kinases, epi-genetic controlling factors and many well-known disease resistant proteins, are identified after Xoo infection suggesting that they may be functionally relevant to Xoo resistance. In particular, we found that phosphorylation/dephosphorylation might be a key switch turning on/off many epi-genetic controlling factors, including HDT701, in response to Xoo infection, suggesting that phosphorylation switch overriding the epi-genetic regulation may be a very universal model in the plant disease resistance pathway.ConclusionsThe phosphosites identified in this study would be a big complementation to our current knowledge in the phosphorylation status and sites of rice proteins. This research represents a substantial advance in understanding the rice phosphoproteome as well as the mechanism of rice bacterial blight resistance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0541-2) contains supplementary material, which is available to authorized users.

The Coiled-Coil and Nucleotide Binding Domains of BROWN PLANTHOPPER RESISTANCE14 Function in Signaling and Resistance against Planthopper in Rice

“…pathogen, X. oryzae pv oryzicola (Zhou et al, 2010). WRKY72 protein was also specifically phosphorylated after 24 h of X. oryzae pv oryzae infection (Hou et al, 2015). We found that the BPH14 protein and its CC, NB, and CN domains interacted with WRKY46 and WRKY72, protecting them from UPS degradation.…”

A Quantitative Proteomic Analysis of Brassinosteroid-induced Protein Phosphorylation in Rice (Oryza sativa L.)

“…Of the phosphosites detected at 0 h, 89.7% were phosphoserine, 9.9% were phosphothreonine, and 0.4% were phosphotyrosines ( Figure 1B ), and the proportions were similar at the other two sampling times. Emerging evidences have shown that the distribution ratios of phosphorylation amino acids are much conserved in plants, despite the great variety of species, tissue and treatment applied (Han et al, 2014; Lv et al, 2014; Wang K. et al, 2014; Zhang M. et al, 2014; Hou et al, 2015; Qiu et al, 2016). In the three samples, 92.9–93.3% of the peptides carried only one phosphorylation group, 6.5–6.8% of the peptides carried two phosphorylation modifications, whereas only less than 0.3% of peptides had more than two phosphorylation modifications ( Figure 1C ).…”

“…[sF] was annotated to be a low frequency motif in plants by a previous meta-analysis (van Wijk et al, 2014). However, it seemed to be not the case, at least in rice, because two recent studies both found that [sF] was over-represented in rice leaves and developing seeds (Hou et al, 2015; Qiu et al, 2016). In the current study, we detected 252 hits of [sF] in rice young seedlings, which again supported that [sF] is a highly conserved motif for phosphorylation.…”

“…The total protein extraction and digestion were performed by exactly following the methods described by (Hou et al, 2015). For phosphopeptides enrichment, 1 mg digested peptides were dissolved with binding buffer (80% ACN, 5% TFA, 1 M lactic acid), then incubated with 4 mg TiO 2 beads (GL sciences, Torrance, CA, USA) for three times, each time for 30 minutes at room temperature.…”

“…Then, Western blot was conducted following (Hou et al, 2015). The prepared protein samples were resolved in 10% SDS-polyacrylamide gel, and transferred onto a 0.45 μm polyvinylidene fluoride fluoropolymer (PVDF) membrane (Millipore, Darmstadt, Germany) by using an electrophoretic blotting system (Bio-Rad, Hercules, CA, USA).…”