生长温度对不同生育期烟草叶片光合作用及质体色素代谢的影响

为了解不同生长温度对烟草叶片光合速率及质体色素代谢的影响，以‘云烟87’为材料，通过人工气候室模拟云南江川、贵州遵义和河南襄县的气温条件，在烟草移栽—团棵、团棵—现蕾及成熟期进行温度处理，研究不同生长温度对烟叶光合速率、质体色素含量、代谢相关酶活性及相关基因表达的影响。结果表明，在模拟3个地区的生长温度处理下，随烟株生长发育阶段的推进，烟叶光合速率、叶绿素含量和类胡萝卜素含量及代谢相关酶活性变化规律基本一致，呈前低、中高、后期又逐渐降低的抛物线型。总体而言，不同生长温度对不同生育期的烟草叶片光合速率、质体色素含量及代谢相关酶活性和基因表达都有不同程度的影响。相比其他生育期，成熟期温度对烟叶光合速率、叶绿素含量和类胡萝卜素含量的影响最大。具有相对较高生长温度条件的河南襄县更有利于烟叶光合作用的进行和质体色素的积累。贵州遵义地区的气温条件有利于类胡萝卜素的积累。这些研究结果在一定程度上从光合作用及质体色素代谢角度解释3个地区烟草香型风格有较大区别的原因。

Effects of Different Growth Temperatures on Photosynthesis and Plastid Pigment Catabolism of Tobacco Leaves at Different Growth Stages

[Objective][Method]To investigate the effects of different growth temperature on photosynthesis, content of plastid pigments, enzyme activities and gene expression of plastid pigment catabolism in tobacco (Nicotiana tobacum L.) leaves at different growth stages, the tobacco cultivar Yunyan 87 was used as experimental material, and different growth temperature was simulated in artificial climate chambers similar to the temperatures in Jiangchuan of Yunnan, Zunyi of Guizhou, and Xiangxian of Henan province during the transplanting to resettlingSstage, resettling to squaringSstage and matureSstage of Yunyan 87 plants.[Result]The results indicated that the growth temperature treatments simulated to the above-mentioned three regions had similar effects on photosynthetic rate, content of chlorophyll and carotenoid, and activities of metabolism related enzymes with prolonged tobacco growth and development stages, which firstly showed an lower level at early growth stage, then rise at middle growth stage, and gradually decline at mature stage, like a parabolic type. In general, different growth temperature all could influence photosynthetic rate, content of plastid pigments, activities of metabolism related enzymes and gene expression to some extent in tobacco leaves at different growth stages. Compare to other growth stages, the temperature at mature stage demonstrated the most significant effects on photosynthetic rate and content of plastid pigments. [Conclusion]Xiangxian of Henan province, which had higher growth temperature than the other two regions, was more suitable for photosynthesis and accumulation of plastid pigments in tobacco leaves. In addition, the temperature simulated to Zunyi of Guizhou province was also suitable for carotenoid accumulation. These results explains why tobacco leaves from these three regions have great difference in tobacco flavor style based on photosynthesis and plastid pigment catabolism to some extent.