Evidence for a role of raffinose in stabilizing photosystem II during freeze-thaw cycles
Evidence for a role of raffinose in stabilizing photosystem II during freeze-thaw cycles
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DOI：
10.1007/s00425-011-1413-0
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发表时间：
2011-09-01
期刊：
影响因子：
4.3
通讯作者：
Heyer, Arnd G.
中科院分区：
文献类型：
--
作者：
Knaupp, Markus;Mishra, Kumud B.;Heyer, Arnd G.
蔗糖和棉子糖等非还原糖在保护植物细胞免受冷冻损伤方面的作用已被提出用于许多物种，但关于生理效应的报道相互矛盾。使用拟南芥叶肉细胞隔室的非水分级分离表明，低温期间蔗糖和棉子糖在质体中积累，表明其在保护光合机构方面具有生理作用。比较先前描述的A. thaliana及其相应的野生型，登录号Col-0，揭示了缺乏棉子糖对冷冻-解冻循环后叶细胞的电解质渗漏没有影响，支持棉子糖对于保护质膜不是必需的。然而，在原位叶绿素荧光显示，PS II光化学的最大量子产率（F（v）/F（m））和其他荧光参数的冷驯化叶片进行冻融循环中的棉子糖合酶突变体显着低于相应的野生型，表明棉子糖是参与稳定PS II的冷驯化叶片细胞在冻结过程中的损害。
A role of non-reducing sugars like sucrose and raffinose in the protection of plant cells against damage during freezing has been proposed for many species, but reports on physiological effects are conflicting. Non-aqueous fractionation of mesophyll cell compartments in Arabidopsis thaliana was used to show that sucrose and raffinose accumulate in plastids during low temperatures, pointing to a physiological role in protecting the photosynthetic apparatus. Comparing a previously described raffinose synthase (RS) mutant of A. thaliana with its corresponding wild type, accession Col-0, revealed that a lack of raffinose has no effect on electrolyte leakage from leaf cells after freeze-thaw cycles, supporting that raffinose is not essential for protecting the plasma membrane. However, in situ chlorophyll fluorescence showed that maximum quantum yield of PS II photochemistry (F (v)/F (m)) and other fluorescence parameters of cold acclimated leaves subjected to freeze-thaw cycles were significantly lower in the raffinose synthase mutant than in the corresponding wild type, indicating that raffinose is involved in stabilizing PS II of cold acclimated leaf cells against damage during freezing.