Abscisic acid and brassinolide combined application synergistically enhances drought tolerance and photosynthesis of tall fescue under water stress
Abscisic acid and brassinolide combined application synergistically enhances drought tolerance and photosynthesis of tall fescue under water stress
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DOI：
10.1016/j.scienta.2017.10.004
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发表时间：
2018-01-26
影响因子：
4.3
通讯作者：
Xu, Bingcheng
中科院分区：
文献类型：
--
作者：
Chen, Zhifei;Wang, Zhi;Xu, Bingcheng
高羊茅（Festuca arundinacea Schreb.）是一种广泛使用的冷季型草坪草，其生长主要受到水分亏缺的限制。脱落酸（ABA）和芸苔素内酯（BR）是调节植物生理过程和缺水条件下生长的两种重要的应激激素。为了研究水分胁迫条件下外源 ABA 和 BR 对高羊茅生理和光合性能的影响，在三种土壤水分条件下单独施用 ABA（10 和 20 mg L-1）和 BR（0.4 和 0.8 mg L-1）（0.4 mg L-1 BR 和 10 mg L-1 ABA）[75 +/- 5% FC (HW)、50 +/- 5% FC (MW) 和 25 +/- 5% FC (LW)] 在温室中。结果表明，ABA和BR施用显着降低了相对电导率和丙二醛，显着增加了水分胁迫下叶片相对含水量、抗氧化酶活性和脯氨酸含量。 ABA 加 BR 施用在提高抗氧化酶活性方面与 20 mg L-1 的 ABA 同等有效。 ABA 施用降低了气孔导度并降低了蒸腾量和净光合速率（P-n），而 BR 施用通过提高叶绿素含量显着增加了 P-n 和水分利用效率（WUE）。 ABA 和 BR 组合施用与 BR 单独施用一样表现出更高的 P-n 和 WUE。表明ABA与BR配施提高了光合能力，并减轻了水分胁迫下ABA对光合损失的影响。这些都证实了ABA加BR施用在增强高羊茅在水分胁迫下的耐旱性和光合作用方面表现出协同作用。
Tall fescue (Festuca arundinacea Schreb.) is a widely used cool-season turfgrass, and its growth is mainly limited by water deficit. Abscisic acid (ABA) and brassinolide (BR) are two important stress hormones regulating plant physiological processes and growth under water deficit. To investigate effects of exogenous ABA and BR on physiological and photosynthetic performance of tall fescue under water stress conditions, ABA (10 and 20 mg L-1) and BR (0.4 and 0.8 mg L-1) were applied individually and in combination (0.4 mg L-1 BR and 10 mg L-1 ABA) under three soil water regimes [75 +/- 5% FC (HW), 50 +/- 5% FC (MW) and 25 +/- 5% FC (LW)] in the greenhouse. Results revealed that ABA and BR application markedly decreased the relative conductivity and malondialdehyde, notably increased leaf relative water content, antioxidant enzyme activity and proline content under water stress. ABA plus BR application was equally effective in improving the activities of antioxidant enzyme as ABA at 20 mg L-1. ABA application reduced stomatal conductance and decreased both transpiration and net photosynthetic rate (P-n), while BR application significantly increased P-n and water use efficiency (WUE) by enhancing chlorophyll content. The ABA and BR combination application showed higher P-n and WUE as well as BR single application. It indicated that ABA and BR combination application increased photosynthetic capacity, and reduced the effect on photosynthetic loss caused by ABA under water stress. All these confirmed that ABA plus BR application exhibited a synergistic interaction on enhancing drought tolerance and photosynthesis of tall fescue under water stress.