Plant stress memory is linked to high levels of anti-oxidative enzymes over several weeks
Plant stress memory is linked to high levels of anti-oxidative enzymes over several weeks
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DOI：
10.1016/j.envexpbot.2020.104166
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发表时间：
2020-10-01
影响因子：
5.7
通讯作者：
Walter, Julia
中科院分区：
文献类型：
--
作者：
Lukic, Natasa;Kukavica, Biljana;Walter, Julia
干旱胁迫是气候变化下植物的主要胁迫源之一，通过抑制光合作用和引起细胞氧化损伤来抑制植物生长。已有研究表明，植物在经历过干旱后，可以形成干旱胁迫记忆，提高其在反复干旱胁迫下的表现。这种干旱胁迫记忆和可能的交叉胁迫耐受性（在植物受到其他胁迫后提高对干旱的表现）的机制目前尚不清楚。我们的目的是测试以前的涝渍胁迫和干旱胁迫是否会导致反复干旱条件下植物性能的改善以及形态、光合和抗氧化参数的变化。因此，我们在两年多的时间里反复对草皮进行了涝渍和干旱试验。在第三年，植物被充分浇水三周以恢复，然后遭受干旱胁迫两周。经干旱处理的植株在恢复后和干旱期的Rubisco含量、抗氧化酶（PDX、SOD）和叶绿素b水平均有所提高，组织损伤较小。我们首次在草类物种中展示了持续数周的长期干旱胁迫记忆。结果表明，干旱胁迫增强了抗氧化酶的活性，这是草地草抑制氧化损伤和提高后续干旱胁迫耐受性的关键。
Drought stress is one of the major stressors for plants under climate change, depressing growth through inhibition of photosynthesis and causing oxidative cell damage. It has been shown that plants can form a drought stress memory, improving their performance under recurring drought stress after they have been primed by drought before. Mechanisms underlying such a drought stress memory and possible cross-stress tolerance (improved performance to drought after plants have been stressed by other stressors) are currently unclear. We aimed to test whether previous waterlogging stress and drought stress leads to improved performance and changes in morphological, photosynthetic and anti-oxidative parameters under recurring drought. Therefore, we repeatedly subjected Alopecurus pratensis grass plants to waterlogging and drought over two years. In the third year, plants were well-watered for three weeks to recover and then subjected to drought stress for two weeks. Plants primed with drought before showed less tissue damage and higher levels of Rubisco content, anti-oxidative enzymes (PDX, SOD) and chlorophyll b after the recovery and the drought period. We show for the first time a long-term drought stress memory in a grass species, lasting over several weeks. Our results indicate that drought priming enhances the activity of anti-oxidative enzymes, which is key for depressing oxidative damage and for improving tolerance to subsequent drought stress in A. pratensis.