Impact of UV-B irradiation on photosynthetic performance and chloroplast membrane components in Oryza sativa L.
Impact of UV-B irradiation on photosynthetic performance and chloroplast membrane components in Oryza sativa L.
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DOI：
10.1016/j.jphotobiol.2011.05.004
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发表时间：
2011-09-02
影响因子：
5.4
通讯作者：
Ramalho, J. C.
中科院分区：
文献类型：
--
作者：
Lidon, F. C.;Ramalho, J. C.
研究了UV-B辐射对水稻光合相关参数的影响。野生野生植物在萌发后8 ~ 14天，每天1小时进行10窄带（λ 311 nm） UV-B照射7天后，总生物有效UV-B （UVBBE）为2.975 kJ m -2(-1)，总生物有效UV-B （UVBBE）为20.825 kJ m（-2）。气体交换测量结果受到严重影响，在7 d UV-B处理结束后第1天，净光合作用（P-n）、气孔导度和光合能力（A(max)）降低了80%以上。同样，一些荧光参数(F-o, F-v/F-m, F-v'/Fm', phi(e), q（p)和q(e)）和类囊体电子传递（涉及两个光系统）也严重降低。与此同时，叶黄素、胡萝卜素、Chl a、Chl （a + b）和Chl （a/b）值的下降伴随着叶绿体膜脂质过氧化水平的升高，反映了对氧化应激保护的丧失。在UV-B处理结束7天后，大多数荧光参数恢复，但在P-n， A(max)，类囊体电子传递速率，Chl A和脂类以及脂质过氧化水平方面，影响甚至比胁迫结束后立即更强，这表明光合结构的性能明显丧失。然而，对总脂质的影响不大，并伴有主要叶绿体膜脂类相对重量的变化，主要表现为MGDG的减少和磷脂的增加。这表明一种新生脂质合成的能力，允许脂质基质发生质变。值得注意的是，UV-B照射结束后的叶片发育受到的影响要小得多，只有P-n和g(s)值显著降低，几个荧光参数、类囊体电子传递、光合色素（叶黄素和chls）和DEPS值上升，而脂类值接近对照。结果表明，UV-B对辐照叶片的光合结构和性能有全球性影响，但辐照结束后完全发育的叶片损伤程度较低，反映了胁迫结束后植物的显著恢复，这可能构成了这种重要的世界主要粮食作物在偶发UV-B暴露事件下的优势。(C) 2011 Elsevier B.V.版权所有
The impact of UV-B radiation on photosynthetic related parameters was studied in Oryza sativa L cv. Safari plants, after an UV-B irradiation performed 1 h per day for 7 days (between 8 and 14 days after germination) with a ten narrow-band (lambda 311 nm) that resulted in a total biological effective UV-B (UVBBE) of 2.975 kJ M-2 clay(-1) and a total of 20.825 kJ m(-2). Gas exchange measurements were severely affected, showing reductions higher than 80% in net photosynthesis (P-n), stomatal conductance and photosynthetic capacity (A(max)), 1 day after the end of the 7-days UV-B treatment. Similarly, several fluorescence parameters (F-o, F-v/F-m, F-v'/Fm', phi(e), q(p) and q(E)) and thylakoid electron transport (involving both photosystems) were also severely reduced. Concomitantly, a decline of xanthophylls, carotenes, Chl a, Chl (a + b) and Chl (a/b) values was accompanied by the increase of the lipoperoxidation level in chloroplast membranes, altogether reflecting a loss of protection against oxidative stress. Seven days after of the end of UV-B treatment, most fluorescence parameters recovered, but in P-n, A(max), thylakoid electron transport rates, Chl a and lipid classes, as well as the level of lipoperoxidation, the impacts were even stronger than immediately after the end of stress, denoting a clear loss of performance of photosynthetic structures. However, only a moderate impact on total lipids was observed, accompanied by some changes in the relative weight of the major chloroplast membrane lipid classes, with emphasis on the decrease of MGDG and the increase of phospholipids. That suggested an ability to de nova lipid synthesis allowing qualitative changes in the lipid matrix. Notably, the leaves developed after the end of UV-B irradiation showed a much lower impact, with significantly decreased values only in P-n and g(s), rises in several fluorescence parameters, thylakoid electron transport, photosynthetic pigments (xanthophylls and chls) and DEPS, while lipid classes presented values close to control. The results showed a global impact of UV-B in the photosynthetic structures and performance in irradiated leaves, but revealed also a low impairment extent in the leaves entirely developed after the end of the irradiation, reflecting a remarkable recovery of the plant after the end of stress, what could constitute an advantage under occasional UV-B exposure events in this vital worldwide staple food crop. (C) 2011 Elsevier B.V. All rights reserved.