title: Comparative proteomic analysis of the thermotolerant plant Portulaca oleracea acclimation to combined high temperature and humidity stress.
abstract: Elevated temperature and humidity are major environmental factors limiting crop yield and distribution. An understanding of the mechanisms underlying plant tolerance to high temperature and humidity may facilitate the development of cultivars adaptable to warm or humid regions. Under conditions of 90% humidity and 35 °C, the thermotolerant plant Portulaca oleracea exhibits excellent photosynthetic capability and relatively little oxidative damage. To determine the proteomic response that occurs in leaves of P. oleracea following exposure to high temperature and high humidity, a proteomic approach was performed to identify protein changes. A total of 51 differentially expressed proteins were detected and characterized functionally and structurally; these identified proteins were involved in various functional categories, mainly including material and energy metabolism, the antioxidant defense responses, protein destination and storage, and transcriptional regulation. The subset of antioxidant defense-related proteins demonstrated marked increases in activity with exposure to heat and humidity, which led to lower accumulations of H(2)O(2) and O(2)(-) in P. oleracea compared with the thermosensitive plant Arabidopsis thaliana. The quickly accumulations of proline content and heat-shock proteins, and depleting abscisic acid (ABA) via increasing ABA-8'-hydroxylase were also found in P. oleracea under stress conditions, that resulted into greater stomata conductance and respiration rates. On the basis of these findings, we propose that P. oleracea employs multiple strategies to enhance its adaptation to high-temperature and high-humidity conditions.
authors.affiliation: Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Institute of Tibet Plateau Research, Chinese Academy of Science, Kunming 650204, China.
authors.forename: Yunqiang
authors.initials: Y
authors.lastname: Yang
authors.forename: Jinhui
authors.initials: J
authors.lastname: Chen
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.forename: Cécile
authors.initials: C
authors.lastname: Ben
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Todd
authors.forename: Jisen
authors.initials: J
authors.lastname: Shi
authors.forename: Yongping
authors.initials: Y
authors.lastname: Yang
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Hu
mesh_terms: D000064:Acclimatization; D000975:Antioxidants / Q000378:metabolism; D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D016000:Cluster Analysis; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D006358:Hot Temperature; D006813:Humidity; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D031822:Portulaca / Q000378:metabolism* / Q000502:physiology; D040901:Proteomics; D017382:Reactive Oxygen Species / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000975:Antioxidants; D018797:Cell Cycle Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors