Lu Shaoyun, Su Wei, Li Haihang, Guo Zhenfei
Biotechnology Laboratory for Forages and Turfgrass, College of Life Science, South China Agricultural University, Wu Shan Street, Guangzhou 510642, China.
Plant Physiol Biochem. 2009 Feb;47(2):132-8. doi: 10.1016/j.plaphy.2008.10.006. Epub 2008 Oct 26.
Drought is a major limiting factor for turfgrass growth. Protection of triploid bermudagrass against drought stress by abscisic acid (ABA) and its association with hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) were investigated. ABA treatment increased relative water content, decreased ion leakage and the percentage of dead plants significantly under drought stress. Superoxide dismutase (SOD) and catalase (CAT) activities increased in both ABA-treated and control plants, but more in ABA-treated plants, under drought stress. Malondialdehyde, an indicator of plant lipid peroxidation, was lower in ABA-treated plants than in control plants, indicating that ABA alleviated drought-induced oxidative injury. ABA treatment increased H(2)O(2) and NO contents. ABA-induced SOD and CAT activities could be blocked by scavengers of H(2)O(2) and NO, and inhibitors of H(2)O(2) and NO generation. The results indicated that H(2)O(2) and NO were essential for ABA-induced SOD and CAT activities. Both H(2)O(2) and NO could induce SOD and CAT activities individually. SOD and CAT induced by H(2)O(2) could be blocked by scavenger of NO and inhibitors of NO generation, while SOD and CAT induced by NO could not be blocked by scavenger of H(2)O(2) and inhibitor of H(2)O(2). The results revealed that ABA-induced SOD and CAT activities were mediated sequentially by H(2)O(2) and NO, and NO acted downstream of H(2)O(2).
干旱是草坪草生长的主要限制因素。研究了脱落酸（ABA）对三倍体狗牙根干旱胁迫的保护作用及其与过氧化氢（H₂O₂）和一氧化氮（NO）的关系。在干旱胁迫下，ABA处理显著提高了相对含水量，降低了离子渗漏和死亡植株的百分比。干旱胁迫下，ABA处理植株和对照植株的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性均增加，但ABA处理植株增加得更多。丙二醛是植物脂质过氧化的指标，ABA处理植株中的丙二醛含量低于对照植株，表明ABA减轻了干旱诱导的氧化损伤。ABA处理增加了H₂O₂和NO的含量。ABA诱导的SOD和CAT活性可被H₂O₂和NO的清除剂以及H₂O₂和NO生成的抑制剂所阻断。结果表明，H₂O₂和NO对ABA诱导的SOD和CAT活性至关重要。H₂O₂和NO均可单独诱导SOD和CAT活性。H₂O₂诱导的SOD和CAT可被NO清除剂和NO生成抑制剂所阻断，而NO诱导的SOD和CAT不能被H₂O₂清除剂和H₂O₂抑制剂所阻断。结果表明，ABA诱导的SOD和CAT活性依次由H₂O₂和NO介导，且NO作用于H₂O₂的下游。
