Changes in morphological, physiological, and biochemical responses to different levels of drought stress in chinese cork oak (Quercus variabilis Bl.) seedlings

作者：Min Wu, Wenhui Zhang, Chengzhi Ma, J. Y. Zhou · 发表于：Russian Journal of Plant Physiology · 年份：2013 · DOI：10.1134/s1021443713030151 · 被引用次数：36 · 研究领域：Plant Stress Responses and Tolerance、Seedling growth and survival studies、Plant Water Relations and Carbon Dynamics

Changes in growth, leaf water status, pigments, osmolytes, activities of peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX), and ascorbic acid (ASA) content were investigated in Chinese cork oak (Quercus variabilis Bl.) seedlings. Three-month-old seedlings were subjected to four drought cycles (30, 60, 90, and 120 days) and four drought intensities (80, 60, 40, and 20% field capacity (FC)). The seedlings had optimal height, basal diameter, and leaf water status at 80% FC. These parameters significantly decreased as drought intensity increased. The total root length, diameter, and surface area at 60% FC significantly increased compared with those at 80% FC. However, at 40 and 20% FC these parameters significantly decreased compared with those at 80% FC. The ratio of total root length to seedling height significantly increased with increasing drought intensity. The contents of chlorophyll a + b (Chl a + b ) and carotenoids (Car) significantly decreased at 40 and 20% FC. However, no significant changes in Chl a /Chl b and Car/Chl a + b ratios were observed among the four drought intensities. Comparatively, the seedlings accumulated more soluble sugars and proline, as well as they demonstrated the higher POD, SOD, CAT, APX activities and ASA content at >40% FC. However, prolonged drought stress at 20% FC suppressed antioxidant activities and osmolyte accumulation, leading to a rapid increase in lipid peroxidation. These results suggest th...