24-Epibrassinosteroid alleviate drought-induced inhibition of photosynthesis in Capsicum annuum
24-Epibrassinosteroid alleviate drought-induced inhibition of photosynthesis in Capsicum annuum
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DOI：
10.1016/j.scienta.2012.11.012
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发表时间：
2013-02-04
影响因子：
4.3
通讯作者：
Ogweno, Joshua Otieno
中科院分区：
文献类型：
--
作者：
Hu, Wen-hai;Yan, Xiao-hong;Ogweno, Joshua Otieno
为了研究油菜素内酯在植物耐旱性中的作用，以辣椒（Capsicum annuum L cv.龙口早娇）植株的24-表油菜素（EBR，0.01 mg L ~（-1）EBR）处理。辣椒植株经受干旱（45%相对土壤含水量，RSWC）10天，然后返回到良好浇水条件下5天。本研究表明，干旱胁迫使辣椒生长受到抑制，叶片光合速率降低，干旱抑制光合作用可能是由于非气孔因素造成的。干旱还降低了叶绿体对吸收光能的利用率，尽管干旱诱导了非光化学猝灭系数（NPQ）的增加，但光抑制是由过量的吸收光能引起的。有趣的是，EBR处理显着缓解干旱引起的光合作用的抑制，这可能是特别归因于增加的CO2同化能力和光利用效率。EBR还显着减轻干旱引起的光抑制的激发能量耗散的光系统II（PSII）的捕光复合体的热量。EBR通过提高叶片光系统Ⅱ触角的光能利用效率和激发能耗散，缓解干旱对光合作用的不利影响。(C)2012爱思唯尔有限公司版权所有。
To investigate the role of brassinosteroids in the drought-tolerance of plants, leaf gas exchange and chlorophyll fluorescence parameters were examined in pepper (Capsicum annuum L cv. Longkouzaojiao) plants with or without 24-epibrassinolide (EBR, 0.01 mg L-1 EBR) treatment. Pepper plants were subjected to drought (45% relative soil water content, RSWC) for 10 d and then returned to well-watered conditions for 5 d. In this study, drought treatment impaired the pepper growth and reduced leaf photosynthetic rate, and drought-inhibition of photosynthesis may be due to non-stomatal factor. Drought also reduced the utilization of absorbed light energy in chloroplasts, and photoinhibition was caused by excess absorbed light energy in spite of drought-induced the increase of non-photochemical quenching coefficient (NPQ). Interestedly, EBR treatment significantly alleviated drought-induced inhibition of photosynthesis, which may be particularly attributed to the increase in capacity of CO2 assimilation and the efficiency of light utilization. EBR also significantly alleviated drought-induced photoinhibition by dissipation of excitation energy as heat from the light harvesting complex in photosystem II (PSII). We concluded that EBR could alleviate the detrimental effects of drought on photosynthesis by increasing the efficiency of light utilization and dissipation of excitation energy in the PSII antennae in leaves. (C) 2012 Elsevier B.V. All rights reserved.