Effect of drought on pigments, osmotic adjustment and antioxidant enzymes in six woody plant species in karst habitats of southwestern China
Effect of drought on pigments, osmotic adjustment and antioxidant enzymes in six woody plant species in karst habitats of southwestern China
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DOI：
10.1016/j.envexpbot.2010.11.012
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发表时间：
2011-06-01
影响因子：
5.7
通讯作者：
Yang, Rui
中科院分区：
文献类型：
--
作者：
Liu, Changcheng;Liu, Yuguo;Yang, Rui
干旱胁迫是限制中国西南喀斯特生境植物生存和生长的重要因素之一。详细了解不同生长形式的乡土植物对干旱胁迫的生理生态响应有助于植被恢复计划的成功。两种灌木，火棘和金蔷薇，和四棵树。将构叶树、樟、化香树和青檀随机分为4个干旱处理，即充分供水、轻度干旱胁迫、中度干旱胁迫和重度干旱胁迫。中午水势，PSII光化学的最大量子效率（F-v/F-m），色素，渗透溶质（可溶性糖和脯氨酸），细胞损伤，和抗氧化酶（超氧化物歧化酶，过氧化氢酶和过氧化物酶）进行了研究。干旱胁迫显著降低了色素含量，但增加了类胡萝卜素与总叶绿素的比例。在长期严重干旱胁迫下，两种灌木的F-v/F-m值均高于4种乔木，而中午水势的下降幅度较小，丙二醛含量和离子渗漏率的增加幅度较小。长时间的严重干旱胁迫显著降低了4种乔木的渗透压物质积累和抗氧化酶活性，但显著提高了2种灌木的脯氨酸含量和超氧化物歧化酶活性，并显著提高了梧桐的过氧化物酶活性。抗氧化酶活性之间、渗透溶质含量与抗氧化酶活性之间存在正相关关系。这些结果表明，这两种灌木比4种乔木具有更强的渗透调节和抗氧化保护能力，从而对严重干旱胁迫具有更强的耐受性。(C)2010爱思唯尔有限公司版权所有。
Drought stress is one of the most important factors limiting the survival and growth of plants in the harsh karst habitats of southwestern China. Detailed knowledge about the ecophysiological responses of native plants with different growth forms to drought stress could contribute to the success of re-vegetation programs. Two shrubs, Pyracantha fortuneana and Rosa cymosa, and four trees. Broussonetia papyrifera, Cinnamomum bodinieri, Platycarya longipes and Pteroceltis tatarinowii, were randomly assigned to four drought treatments, i.e. well-watered, mild drought stress, moderate drought stress, and severe drought stress. Midday water potential, the maximum quantum efficiency of PSII photochemistry (F-v/F-m), pigments, osmotic solutes (soluble sugars and proline), cellular damages, and antioxidant enzymes (superoxide dismutase, catalase and peroxidase) were investigated. Drought stress significantly decreased pigments content, but increased the ratio of carotenoids to total chlorophylls in the studied species. After prolonged severe drought stress, the two shrubs exhibited higher F-v/F-m less reductions of midday water potential, and lower increases of malondialdehyde content and ion leakage than the four trees. Prolonged severe drought stress largely decreased accumulations of osmotic solutes and activities of antioxidant enzymes in the four trees, but significantly increased proline content and superoxide dismutase activity in the two shrubs and peroxidase activity in P. fortuneana. The positive relationships were observed among activities of antioxidant enzymes, and between contents of osmotic solutes and activities of antioxidant enzymes. These findings suggested that the two shrubs had higher tolerance to severe drought stress than the four trees due to higher capacities of osmotic adjustment and antioxidant protection. (C) 2010 Elsevier B.V. All rights reserved.