Chen Juanli, Zhao Xueyong, Liu Xinping, Zhang Yaqiu, Luo Yayong, Luo Yongqing, He Zhaoquan, Zhang Rui
Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
School of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China.
Plants (Basel). 2019 Jul 23;8(7):244. doi: 10.3390/plants8070244.
The availability of water is the critical factor driving plant growth, physiological responses, population and community succession in arid and semiarid regions, thus a precipitation addition-reduction platform with five experimental treatments, was established to explore the growth and physiology of two psammophytes (also known as psammophiles) to precipitation manipulation in Horqin Sandy Land. Changes in coverage and density were measured, and antioxidant enzymes and osmoregulatory substances in both of the studied species were determined. Investigation results showed that the average vegetation coverage increased with an increasing precipitation, and reached a maximum in July. Under the -60% precipitation treatment, accounted for a large proportion of the area, but was the dominant species in the +60% treatment. was found to have higher a drought stress resistance than From days 4 to 7 after rainfall, under precipitation reduction showed obvious water stress. The malondialdehyde (MDA) content of was higher than that of , but that of had the lower relative water content (RWC). The MDA content in the precipitation reduction treatments of the two studied species was higher than that in the precipitation addition treatments from days 4 to 10. Peroxidase (POD) and superoxide dismutase (SOD) activity and the soluble proteins and free proline content of were higher than those of . The free proline content of and increased with increasing drought stress. Our data illustrated that had a higher drought stress resistance than , which was correlated with the augmentation of some antioxidant enzymes and osmoregulatory substance. The adaptive mechanism provides solid physiological support for an understanding of psammophyte adaptation to drought stress, and of community succession or species manipulation for desertified land restoration.
水的可利用性是驱动干旱和半干旱地区植物生长、生理反应、种群和群落演替的关键因素，因此，在科尔沁沙地建立了一个具有五种实验处理的降水增减平台，以探究两种沙生植物对降水调控的生长和生理响应。测量了盖度和密度的变化，并测定了两个研究物种的抗氧化酶和渗透调节物质。调查结果表明，平均植被盖度随降水量增加而增加，并在7月达到最大值。在降水减少60%的处理下， 占面积的很大比例，但在降水增加60%的处理下， 是优势种。发现 比 具有更高的抗旱性。降雨后第4至7天，降水减少处理下的 表现出明显的水分胁迫。 的丙二醛（MDA）含量高于 ，但其相对含水量（RWC）较低。在第4至10天，两个研究物种降水减少处理中的MDA含量高于降水增加处理。 的过氧化物酶（POD）和超氧化物歧化酶（SOD）活性以及可溶性蛋白和游离脯氨酸含量均高于 。 和 的游离脯氨酸含量随干旱胁迫加剧而增加。我们的数据表明， 比 具有更高的抗旱性，这与一些抗氧化酶和渗透调节物质的增加有关。这种适应机制为理解沙生植物对干旱胁迫的适应以及荒漠化土地恢复中的群落演替或物种调控提供了坚实的生理支持。
