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冬季小麦叶片光合作用对温度响应方式的变化

江华, 师生波, 许大全

中科院上海植物生理研究所.上海 200032；中科院西北高原生物研究所.青海,西宁 810001

摘要

冬季田间生长的小麦离体叶片净光合速率(Pn)对温度的响应有两种方式。在12月上旬可以观测到第一种方式。在离体叶片周围空气温度从10℃逐步升到30℃后的1h内Pn逐渐升高,在随后气温逐步降低到10℃的过程中,Pn都比先前升温过程中同样温度下的数值高。30℃下叶片胞间CO_(2)浓度(Ci)降低和叶片无机磷含量增高表明,这种响应方式可能起因于一些光合碳同化酶活性的增高。在12月中旬以后可以观测到第二种方式。Pn在30℃下的1h内逐步下降,在随后的降温过程中Pn都比升温过程中同样温度下的数值低。30℃下叶片Ci和膜透性增高表明,这种响应方式可能是适应冬季低温的光合机构膜系统在高温下遭受破坏的结果。

关键词： 净光合速率; 低温适应; 温度响应; 胞间CO_(2)浓度; 磷限制; 膜透性; 小麦

Change in the pattern of photosynthetic response to temperature in wheat leaves in winter

Jiang Hua, Shi Shengbo, Xu Daquan

Shanghai Institute of Plant Physiology,Chinese Academy of Sciences.Shanghai 200032；China

Abstract

There were two patterns of the response of net photosynthetic rate (Pn) to temperature in detached leaves of wheat grown in the field in winter. One pattern was observed at the beginning of December. After the air temperature around leaves was shifted from 10deg C to 30deg C by 5deg C steps, Pn increased gradually with time at 30deg C. And when the air temperature was decreased by the same steps to 10deg C, the values of Pn were higher than those measured at the same temperatures during the process of increasing temperature. The first pattern probably originates from an enhancement of the activities of some enzymes involved in the photosynthetic carbon assimilation, as shown by both the decrease of intercellular CO_(2) concentration (Ci) and the increase in phosphate content (Pi) in detached leave at 30deg C. Another pattern was observed after the middle of December. In contrast to the first pattern, Pn decreased gradually with time at 30deg C and the values of Pn measured in the subsequent process of lowering temperature were lower than those measured at the same temperature in the process of increasing temperature. The increases in both Ci and the membrane permeability observed at 30deg C indicate that the second pattern is likely a result of injury caused by high temperature to the membrane system of the photosynthetic apparatus acclimated to low temperatures in winter.

Key words: Net photosynthetic rate;Acclimation to low temperature;Response to temperature;Intercellular CO_(2) concentration;Phosphate limitation;Membrane permeability;Wheat

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引用本文：

江华, 师生波, 许大全. 冬季小麦叶片光合作用对温度响应方式的变化[J]. 生理学报 2000; 52 (1): .

Jiang Hua, Shi Shengbo, Xu Daquan. Change in the pattern of photosynthetic response to temperature in wheat leaves in winter. Acta Physiol Sin 2000; 52 (1): (in Chinese with English abstract).