Du Feng, Shi Huijun, Zhang Xingchang, Xu Xuexuan
Institute of soil and Water Conservation, Northwest Sci-Tech University of Agriculture and Forestry, Yangling, Shaanxi, China; Institute of soil and Water Conservation, Chinese Academy of Science, Yangling, Shaanxi, China; State key laboratory of soil erosion and dryland farming on Loess Plateau, Yangling, Shaanxi, China.
Institute of soil and Water Conservation, Northwest Sci-Tech University of Agriculture and Forestry, Yangling, Shaanxi, China.
PLoS One. 2014 Jun 10;9(6):e98872. doi: 10.1371/journal.pone.0098872. eCollection 2014.
Drought can impact local vegetation dynamics in a long term. In order to predict the possible successional pathway of local community under drought, the responses of some drought resistance indices of six successional seral species in the semi-arid Loss Hilly Region of China were illustrated and compared on three levels of soil water deficits along three growing months (7, 8 and 9). The results showed that: 1) the six species had significant differences in SOD, POD activities and MDA content. The rank correlations between SOD, POD activities and the successional niche positions of the six species were positive, and the correlation between MDA content and the niche positions was negative; 2) activities of SOD, CAT and POD, and content of proline and MDA had significant differences among the three months; 3) there existed significant interactions of SOD, CAT, POD activities and MDA content between months and species. With an exception, no interaction of proline was found. Proline in leaves had a general decline in reproductive month; 4) SOD, CAT, POD activities and proline content had negative correlations with MDA content. Among which, the correlation between SOD activity and MDA content was significant. The results implied that, in arid or semiarid region, the species at later successional stage tend to have strong drought resistance than those at early stage. Anti-drought indices can partially interpret the pathway of community succession in the drought impacted area. SOD activity is more distinct and important on the scope of protecting membrane damage through the scavenging of ROS on exposure to drought.
干旱会长期影响当地植被动态。为预测干旱条件下当地群落可能的演替路径，在中国半干旱黄土丘陵区，选取了6个演替系列物种，研究其在3个生长月份（7月、8月和9月）的3个土壤水分亏缺水平下，部分抗旱指标的响应情况并进行比较。结果表明：1）6个物种在超氧化物歧化酶（SOD）、过氧化物酶（POD）活性和丙二醛（MDA）含量上存在显著差异。SOD、POD活性与6个物种的演替生态位位置呈正秩相关，MDA含量与生态位位置呈负相关；2）SOD、过氧化氢酶（CAT）和POD活性以及脯氨酸和MDA含量在3个月份间存在显著差异；3）月份和物种之间SOD、CAT、POD活性以及MDA含量存在显著交互作用。脯氨酸除外，未发现交互作用。叶片中的脯氨酸在生殖月份普遍下降；4）SOD、CAT、POD活性和脯氨酸含量与MDA含量呈负相关。其中，SOD活性与MDA含量的相关性显著。结果表明，在干旱或半干旱地区，演替后期的物种比早期物种往往具有更强的抗旱性。抗旱指标可以部分解释干旱影响地区群落演替的路径。在干旱条件下，SOD活性在通过清除活性氧保护膜损伤方面更为明显和重要。
