title: Heat shock proteins in relation to heat stress tolerance of creeping bentgrass at different N levels.
abstract: Heat stress is a primary factor causing summer bentgrass decline. Changes in gene expression at the transcriptional and/or translational level are thought to be a fundamental mechanism in plant response to environmental stresses. Heat stress redirects protein synthesis in higher plants and results in stress protein synthesis, particularly heat shock proteins (HSPs). The goal of this work was to analyze the expression pattern of major HSPs in creeping bentgrass (Agrostis stolonifera L.) during different heat stress periods and to study the influence of nitrogen (N) on the HSP expression patterns. A growth chamber study on 'Penn-A4' creeping bentgrass subjected to 38/28°C day/night for 50 days, was conducted with four nitrate rates (no N-0, low N-2.5, medium N-7.5, and high N-12.5 kg N ha-1) applied biweekly. Visual turfgrass quality (TQ), normalized difference vegetation index (NDVI), photochemical efficiency of photosystem II (Fv/Fm), shoot electrolyte leakage (ShEL), and root viability (RV) were monitored, along with the expression pattern of HSPs. There was no difference in measured parameters between treatments until week seven, except TQ at week five. At week seven, grass at medium N had better TQ, NDVI, and Fv/Fm accompanied by lower ShEL and higher RV, suggesting a major role in improved heat tolerance. All the investigated HSPs (HSP101, HSP90, HSP70, and sHSPs) were up-regulated by heat stress. Their expression patterns indicated cooperation between different HSPs and their roles in bentgrass thermotolerance. In addition, their production seems to be resource dependent. This study could further improve our understanding about how different N levels affect bentgrass thermotolerance.
authors: Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing, China; Department of Crop and Soil Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America.
authors: Kehua
authors: K
authors: Wang
authors: Department of Crop and Soil Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America.
authors: Xunzhong
authors: X
authors: Zhang
authors: Department of Crop and Soil Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America.
authors: Mike
authors: M
authors: Goatley
authors: Department of Crop and Soil Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America.
authors: Erik
authors: E
authors: Ervin
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D031703:Agrostis / Q000378:metabolism / Q000502:physiology*; D000704:Analysis of Variance; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D050888:Heat-Shock Proteins, Small / Q000378:metabolism; D006358:Hot Temperature; D015151:Immunoblotting; D009584:Nitrogen / Q000378:metabolism*; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism / Q000502:physiology; D018520:Plant Shoots / Q000378:metabolism / Q000502:physiology; D013312:Stress, Physiological / Q000502:physiology; D014157:Transcription Factors / Q000378:metabolism; D015854:Up-Regulation
chemical_list: C115569:HSP101 protein, plant; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D050888:Heat-Shock Proteins, Small; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D014157:Transcription Factors; D009584:Nitrogen