Differential Effects of Cold Stress on Chloroplasts Structures and Photosynthetic Characteristics in Cold-Sensitive and Cold-Tolerant Cultivars of Sugarcane
Differential Effects of Cold Stress on Chloroplasts Structures and Photosynthetic Characteristics in Cold-Sensitive and Cold-Tolerant Cultivars of Sugarcane
复制标题
冷胁迫对敏感和耐冷甘蔗品种叶绿体结构和光合特性的差异影响
DOI：
10.1007/s12355-017-0527-5
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发表时间：
2018-02-01
期刊：
影响因子：
1.9
通讯作者：
He, Zhen-Li
中科院分区：
文献类型：
--
作者：
Li, Su-Li;Li, Zhi-Gang;He, Zhen-Li
冷冻经常导致甘蔗产量的重大损失。以桂糖28（桂糖28）和源林6号（源林6号）为材料，研究了甘蔗品种的耐冷性。在种植后245天，将处于早熟阶段的植物暴露于冷胁迫（0 °C）0、2、4和6天。测定了低温胁迫下叶绿体结构、微管和生理指标的变化。低温胁迫下，GT28的形态和叶绿体超微结构正常，而YL6的形态和叶绿体超微结构受损严重，叶绿体中淀粉粒积累明显。低温胁迫开始时，品种GT 28的微管比品种YL6的微管解聚更明显。随着低温胁迫时间的延长，YL6的微管数量明显减少，叶绿体膜变得模糊不清，而GT 28的微管荧光增强，表明微管结构发生了重组。因此，低温胁迫下，品种GT 28表现出比YL6更强的光合活性。GT28的抗寒性与其叶绿体结构完整、微管结构稳定、生理代谢平衡有关。这些结果表明，低温胁迫下稳定的叶绿体结构和微管结构是甘蔗品种抗寒性的重要生理基础。
Freezing often results in a significant loss of sugarcane production. An investigation was conducted in two sugarcane cultivars, GT28 (Guitang 28, cold tolerant) and YL6 (Yuanlin 6, cold sensitive) to understand the cold tolerance mechanisms. The plants at early ripening stage, 245 days after planting, were exposed to cold stress (0 °C) for 0, 2, 4, and 6 days. The changes in chloroplast structure, microtubule, and physiological parameters under cold stress were determined. The morphology and chloroplast ultrastructure of the cultivar GT28 were observed normal while those of the cultivar YL6 was severely damaged and accumulation of starch grains in chloroplasts was evident under cold stress. At the beginning of cold stress, the microtubules in the cultivar GT28 was more obviously depolymerized than those in the cultivar YL6. With extended cold stress, the microtubules in the cultivar YL6 decreased noticeably and the chloroplast membrane became indistinct, while the microtubule fluorescence in the cultivar GT28 was intensified, indicating that the structure of microtubules was reorganized. Consequently, the cultivar GT28 showed a greater photosynthetic activity than YL6 under cold stress. The cold tolerance of the cultivar GT28 appeared to be related to the integrity of chloroplast structure, the stability of microtubule structure, and balanced physiological metabolisms. These results revealed that more stable chloroplast structure and microtubule structure under cold stress are the important physiological foundation of cold-tolerant sugarcane cultivars.