|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|5769205||1413236||2018||9 صفحه PDF||ندارد||دانلود کنید|
â¢ABA and BR improved the activities of antioxidant system under drought.â¢BR application compensated photosynthetic loss caused by ABA.â¢ABA plus BR application colligated their respective effect on improving antioxidant activity.â¢ABA plus BR application synergistically enhanced the drought tolerance and photosynthesis of tall fescue.
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 20Â mgÂ Lâ1) and BR (0.4 and 0.8Â mgÂ Lâ1) were applied individually and in combination (0.4Â mgÂ Lâ1 BR and 10Â mgÂ Lâ1 ABA) under three soil water regimes [75Â Â±Â 5% FC (HW), 50Â Â±Â 5% FC (MW) and 25Â Â±Â 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 20Â mgÂ Lâ1. ABA application reduced stomatal conductance and decreased both transpiration and net photosynthetic rate (Pn), while BR application significantly increased Pn and water use efficiency (WUE) by enhancing chlorophyll content. The ABA and BR combination application showed higher Pn 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.
Journal: Scientia Horticulturae - Volume 228, 26 January 2018, Pages 1-9