Differential Responses to Chilling in Stylosanthes guianensis (Aublet) Sw. and Its Mutants
Differential Responses to Chilling in Stylosanthes guianensis (Aublet) Sw. and Its Mutants
复制标题
Stylosanthes guianensis (Aublet) Sw 对寒冷的不同反应。
DOI：
10.2134/agronj2012.0333
复制
发表时间：
2013-03-01
期刊：
影响因子：
2.1
通讯作者：
Guo, Zhenfei
中科院分区：
文献类型：
--
作者：
Lu, Shaoyun;Wang, Xianghui;Guo, Zhenfei
柱花草Stylosanthes guianensis（Aublet）Sw.，是热带、亚热带地区重要的豆科牧草，对低温胁迫敏感。为了解其抗冷生理机制，对3个抗冷突变体及其亲本品种CIAT 184的抗氧化和光合生理响应进行了分析比较。超氧化物歧化酶、过氧化氢酶和抗坏血酸过氧化物酶活性以及抗坏血酸和谷胱甘肽含量在6 ℃低温处理后4d内均呈上升趋势，随后逐渐下降。低温降低了净光合速率，最大光化学效率，光系统II（PSII）光化学的量子效率，光化学猝灭效率，并分配到PSII光化学的激发能，而较高的水平保持在突变体比CIAT 184。在冷却过程中，热能耗散增加，突变体和CIAT 184之间没有差异。冷冻导致过量能量激发（E-x）的增加，但突变体的E-x水平低于CIAT 184。结果表明，低温诱导的抗氧化防御系统水平的提高可能会提高突变体对低温诱导的氧化损伤的光合保护能力，从而提高其抗冷性。
Stylosanthes guianensis (Aublet) Sw., an important forage legume in tropical and subtropical regions, is sensitive to chilling stress. To understand its physiological mechanism of chilling resistance, physiological responses to chilling in antioxidants and photosynthesis in three gamma-ray-irradiated chilling-resistant mutants and the parent cultivar CIAT184 were analyzed and compared. Activities of superoxide dismutase, catalase, and ascorbate peroxidase and contents of ascorbic acid and glutathione increased in all plants within 4d after chilling treatment at 6 degrees C, followed by a gradual decrease. Chilling decreased the net photosynthetic rate, the maximum photochemical efficiency, quantum efficiency of photosystem II (PSII) photochemistry, photochemical quenching efficient, and excitation energy allocated to PSII photochemistry, while higher levels were maintained in the mutants than in CIAT184. Thermal energy dissipation increased during chilling and showed no difference between the mutants and CIAT184. Chilling resulted in an increase in the excess of energy excitation (E-x), but the mutants had lower levels of E-x than CIAT184. The results suggest that the higher levels of the antioxidant defense system induced by low temperature in the mutants may improve protection of photosynthesis against chilling-induced oxidative damage and increase chilling resistance.