Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ 08901, United States.
J Plant Physiol. 2010 Nov 15;167(17):1477-85. doi: 10.1016/j.jplph.2010.05.006. Epub 2010 Jul 31.
Protein metabolism and expression play important role in plant adaptation to water stress. The objectives of this study were to examine proteomic responses to water stress induced by polyethylene glycol (PEG) in creeping bentgrass (Agrostis stolonifera L.) leaves and to identify proteins associated with stress tolerance. Plants of two cultivars ('Penncross' and 'Penn-A4') differing in water stress tolerance were grown in sand irrigated daily with water (control) or PEG solution (osmotic potential of -0.66MPa) to induce water stress, for 28d in growth chambers. Shoot extension rate, relative water content and cell membrane stability were measured to compare drought tolerance between the two cultivars. All parameters maintained at a significantly higher level in 'Penn-A4' than in 'Penncross' under PEG treatment. After 28d of water stress, proteins were extracted from leaves and separated by difference gel electrophoresis. Among 56 stress-responsive protein spots, 46 were identified using mass spectrometry. Some proteins involved in primary nitrogen and carbon metabolism were down-regulated by PEG-induced water stress in both cultivars. The abundance of antioxidant enzyme proteins (ascorbate peroxidase, catalase and glutathione-S-transferase) increased under water stress, particularly ascorbate peroxidase in 'Penn-A4'. The abundance levels of actins, UDP-sulfoquinovose synthase and glucan exohydrolase were greater in 'Penn-A4' than in 'Penncross' under PEG treatment. Our results suggest that proteins involved in membrane synthesis, cell wall loosening, cell turgor maintenance, and antioxidant defense may play roles in perennial grass adaptation to PEG-induced water stress.
蛋白质代谢和表达在植物适应水分胁迫中起着重要作用。本研究的目的是研究聚乙二醇（PEG）诱导的匍匐翦股颖（Agrostis stolonifera L.）叶片水分胁迫下的蛋白质组响应，并鉴定与胁迫耐受相关的蛋白质。两个品种（‘Penncross’和‘Penn-A4’）的植物在生长室内生长，每天用浇水（对照）或 PEG 溶液（渗透势为-0.66MPa）灌溉沙壤土，以诱导水分胁迫，持续 28d。用 Shoot Extension Rate、Relative Water Content 和 Cell Membrane Stability 来比较两个品种的耐旱性。PEG 处理下，‘Penn-A4’的所有参数均显著高于‘Penncross’。在水分胁迫 28d 后，从叶片中提取蛋白质并通过差异凝胶电泳分离。在 56 个应激响应蛋白斑点中，使用质谱法鉴定了 46 个。在两个品种中，一些参与初级氮和碳代谢的蛋白质被 PEG 诱导的水分胁迫下调。抗氧化酶蛋白（抗坏血酸过氧化物酶、过氧化氢酶和谷胱甘肽-S-转移酶）的丰度在水分胁迫下增加，特别是在‘Penn-A4’中。在 PEG 处理下，‘Penn-A4’中肌动蛋白、UDP-硫酸奎诺糖合酶和葡聚糖外切水解酶的丰度水平高于‘Penncross’。我们的研究结果表明，参与膜合成、细胞壁疏松、细胞膨压维持和抗氧化防御的蛋白质可能在多年生草适应 PEG 诱导的水分胁迫中起作用。
