title: A comparative proteomic analysis of Pinellia ternata leaves exposed to heat stress.
abstract: Pinellia ternata is an important traditional Chinese medicinal plant. The growth of P. ternata is sensitive to high temperatures. To gain a better understanding of heat stress responses in P. ternata, we performed a comparative proteomic analysis. P. ternata seedlings were subjected to a temperature of 38 °C and samples were collected 24 h after treatment. Increased relative ion leakage and lipid peroxidation suggested that oxidative stress was frequently generated in rice leaves exposed to high temperature. Two-dimensional electrophoresis (2-DE) was used to analyze heat-responsive proteins. More than 600 protein spots were reproducibly detected on each gel; of these spots, 20 were up-regulated, and 7 were down-regulated. A total of 24 proteins and protein species were successfully identified by MALDI-TOF/TOF MS. These proteins and protein species were found to be primarily small heat shock proteins (58%) as well as proteins involved in RNA processing (17%), photosynthesis (13%), chlorophyll biosynthetic processes (4%), protein degradation (4%) and defense (4%). Using 2-DE Western blot analysis, we confirmed the identities of the cytosolic class II small heat shock protein (sHSPs-CII) identified by MS. The expression levels of four different proteins [cytosolic class I small heat shock protein (sHSPs-CI), sHSPs-CII, mitochondrial small heat shock protein (sHSPs-MIT), glycine-rich RNA-binding protein (GRP)] were analyzed at the transcriptional level by quantitative real-time PCR. The mRNA levels of three sHSPs correlated with the corresponding protein levels. However, GRP was down-regulated at the beginning of heat stress but then increased substantially to reach a peak after 24 h of heat stress. Our study provides valuable new insight into the responses of P. ternata to heat stress.
authors.affiliation: Institute of Chinese Medicinal Materials, Nanjing Agricultural University, Nanjing 210095, China. gqs@njau.edu.cn.
authors.forename: Yunhao
authors.initials: Y
authors.lastname: Zhu
authors.forename: Guosheng
authors.initials: G
authors.lastname: Zhu
authors.forename: Qiaosheng
authors.initials: Q
authors.lastname: Guo
authors.forename: Zaibiao
authors.initials: Z
authors.lastname: Zhu
authors.forename: Changlin
authors.initials: C
authors.lastname: Wang
authors.forename: Zuoyi
authors.initials: Z
authors.lastname: Liu
mesh_terms: D002734:Chlorophyll / Q000096:biosynthesis; D015536:Down-Regulation / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006358:Hot Temperature; D015227:Lipid Peroxidation / Q000235:genetics; D018384:Oxidative Stress / Q000235:genetics; D010788:Photosynthesis / Q000235:genetics; D030021:Pinellia / Q000235:genetics* / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics* / Q000378:metabolism*; D059748:Proteolysis; D020543:Proteome / Q000235:genetics* / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D006360:Heat-Shock Proteins; D020543:Proteome; D002734:Chlorophyll