Proteomic identification of OsCYP2, a rice cyclophilin that confers salt tolerance in rice (Oryza sativa L.) seedlings when overexpressed

Abstract

BackgroundHigh Salinity is a major environmental stress influencing growth and development of rice. Comparative proteomic analysis of hybrid rice shoot proteins from Shanyou 10 seedlings, a salt-tolerant hybrid variety, and Liangyoupeijiu seedlings, a salt-sensitive hybrid variety, was performed to identify new components involved in salt-stress signaling.ResultsPhenotypic analysis of one protein that was upregulated during salt-induced stress, cyclophilin 2 (OsCYP2), indicated that OsCYP2 transgenic rice seedlings had better tolerance to salt stress than did wild-type seedlings. Interestingly, wild-type seedlings exhibited a marked reduction in maximal photochemical efficiency under salt stress, whereas no such change was observed for OsCYP2-transgenic seedlings. OsCYP2-transgenic seedlings had lower levels of lipid peroxidation products and higher activities of antioxidant enzymes than wild-type seedlings. Spatiotemporal expression analysis of OsCYP2 showed that it could be induced by salt stress in both Shanyou 10 and Liangyoupeijiu seedlings, but Shanyou 10 seedlings showed higher OsCYP2 expression levels. Moreover, circadian rhythm expression of OsCYP2 in Shanyou 10 seedlings occurred earlier than in Liangyoupeijiu seedlings. Treatment with PEG, heat, or ABA induced OsCYP2 expression in Shanyou 10 seedlings but inhibited its expression in Liangyoupeijiu seedlings. Cold stress inhibited OsCYP2 expression in Shanyou 10 and Liangyoupeijiu seedlings. In addition, OsCYP2 was strongly expressed in shoots but rarely in roots in two rice hybrid varieties.ConclusionsTogether, these data suggest that OsCYP2 may act as a key regulator that controls ROS level by modulating activities of antioxidant enzymes at translation level. OsCYP2 expression is not only induced by salt stress, but also regulated by circadian rhythm. Moreover, OsCYP2 is also likely to act as a key component that is involved in signal pathways of other types of stresses-PEG, heat, cold, or ABA.

Cloning, purification, crystallization and preliminary X-ray crystallographic analysis of a cyclophilin A-like protein fromPiriformospora indica

“…We have found higher expression levels of a cyclophilin A (CypA) homologue in P. indica under salt-stress conditions (unpublished work). This observation is similar to the previously reported role of cyclophilin in conferring salt-stress tolerance in rice (Ruan et al, 2011). Cyclophilins are proteins that are widely distributed and abundantly found in eukaryotic and prokaryotic systems and are present in the cytosol as well as in the nucleus (Wang & Heitman, 2005).…”

Genome wide analysis ofCyclophilingene family from rice and Arabidopsis and its comparison with yeast

“…This observation is similar to the previously reported role of cyclophilin in conferring salinity stress tolerance in rice. 50 Recently we have also reported the sequence-specific 1 H, 13 C and 15 N NMR assignments and preliminary X-ray crystallographic analysis of Cyclophilin A like protein from Piriformospora indica. 51,52 In case of the expression analysis under different developmental stages, the Arabidopsis cyclophilin genes exhibited higher response to the senescence conditions.…”

Towards Understanding Abiotic Stress Signaling in Plants: Convergence of Genomic, Transcriptomic, Proteomic, and Metabolomic Approaches

“…In recent past, several publications have reported that using the comparative transcriptomic approach between contrasting genotypes of rice (IR64 and Pokkali), several differentially regulated genes could be isolated, which then served as useful genes in functional genomic studies (Kumari et al 2009 ;Karan et al 2009 ;Mustafa et al 2010;Kumar et al 2012 ;Soda et al 2013 ). It is also true that the analysis of changes in proteome of crop plants in response to abiotic stresses can also be used as a starting point to fi sh out the genes, which may ultimately serve as the "candidate genes" (Ruan et al 2011 ) In this chapter, we have described the various "omics"-based approaches, which have been employed in recent years to understand the response of plants towards abiotic stresses. For brevity sake, we have restricted our discussion to the identifi cation of signaling molecules, which have been studied by employing the particular "omics" approach.…”