Electrolyte leakage and lipid degradation account for cold sensitivity in leaves of Coffea sp plants
Electrolyte leakage and lipid degradation account for cold sensitivity in leaves of Coffea sp plants
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DOI：
10.1078/0176-1617-00833
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发表时间：
2003-03-01
影响因子：
4.3
通讯作者：
Nunes, MA
中科院分区：
文献类型：
--
作者：
Campos, PS;Quartin, V;Nunes, MA
五种咖啡基因型不同的敏感性低的正温度进行了比较方面的影响，冷却膜的完整性，以及他们的能力，恢复从冷诱导的伤害后复温。通过电解质渗漏、膜脂组成的变化和丙二醛（MDA）在对照条件（25/20 degreesC，白天/夜晚）下、逐渐降温至15/10 degreesC后、低温处理（4 degreesC下3个夜晚）后和在6天内复温至25/20 degreesC后（恢复）的产生来评价膜损伤。C. dewevrei在15/10 ℃和冷却后表现出最高的电解质渗漏。这主要是由于在15/10 ℃下观察到的脂质降解，反映了强烈的膜损伤。此外，低温条件下MDA的产生表明脂质过氧化反应的发生。C.与在其余植物中观察到的相反，从渗透性方面完全没有恢复也推断出dewevrei至冷。Apoata和Piata在冷藏后表现出显著的渗漏值。然而，这种影响在恢复条件下是可逆的。暴露于寒冷（15/10 ℃和3 × 15/4 ℃）对Catuai和lcatu的膜渗透性没有显著影响。此外，在Apoata，Piata，Catuai和Icatu中，即使在低温处理后也没有观察到显著的MDA产生，这表明这四种基因型具有维持膜完整性和/或修复低温引起的膜损伤的能力。Apoata，Piata和，在较低程度上，Catuai，能够科普逐渐降低的温度通过增强脂质生物合成。驯化后，Piata和Catuai表现出降低二半乳糖基二酰甘油与单半乳糖基二酰甘油的比率（MGDG/DGDG），这是由于DGDG合成增强，这代表膜稳定性增加。同样的观察Apoata冷却后，尽管磷脂减少。研究结果表明，低温诱导了柑橘不可逆的膜损伤。dewevrei。我们还得出结论，增加脂质的合成，降低MGDG/DGDG的比例，并在膜不饱和度的变化，在低温驯化过程中发生的可能是关键因素，在保持细胞的完整性，在寒冷。
Five Coffea genotypes differing in their sensitivity to low positive temperatures were compared with regard to the effects of chilling on membrane integrity, as well as their ability to recover from cold-induced injury upon re-warming. Membrane damage was evaluated through electrolyte leakage, changes in membrane lipid composition and malondialdehyde (MDA) production in control conditions (25/20 degreesC, day/night), after a gradual temperature decrease period to 15/10 degreesC, after chilling treatment (3 nights at 4 degreesC) and upon re-warming to 25/20 degreesC during 6 days (recovery). C. dewevrei showed the highest electrolyte leakage at 15/10 degreesC and after chilling. This was due mainly to lipid degradation observed at 15/10 degreesC, reflecting strong membrane damage. Furthermore, MDA production after chilling conditions indicated the occurrence of lipid peroxidation. A higher susceptibility of C. dewevrei to cold also was inferred from the complete absence of recovery as regards permeability, contrary to what was observed in the remaining plants. Apoata and Piata presented significant leakage values after chilling. However, such effects were reversible under recovery conditions. Exposure to cold (15/10 degreesC and 3 x 15/4 degreesC) did not significantly affect membrane permeability in Catuai and lcatu. Furthermore, no significant MDA production was observed even after chilling treatments in Apoata, Piata, Catuai and Icatu, suggesting that the four genotypes had the ability to maintain membrane integrity and/or repair membrane damage caused by low temperatures. Apoata, Piata and, to a lower extent, Catuai, were able to cope with gradual temperature decrease through an enhanced lipid biosynthesis. After acclimation, Piata, and Catuai showed a lowering of digalactosyldiacylglycerol to monogalactosyldiacylglycerol ratio (MGDG/DGDG) as a result of enhanced DGDG synthesis, which represents an increase in membrane stability. The same was observed in Apoata after chilling, in spite of phospholipids decrease. The studied parameters clearly indicated that chilling induced irreversible membrane damage in C. dewevrei. We also concluded that increased lipid synthesis, lower MGDG/DGDG ratio, and changes in membrane unsaturation occurring during acclimation to low temperatures may be critical factors in maintenance of cellular integrity under chilling.