外源24-表油菜素内酯对茶树光合特性的影响

Effects of Exogenous 24-Epibrassinolide on Photosynthetic Characteristics of Tea Plants

以中茶108为试验材料,研究喷施不同浓度(0.10、0.30、0.50 mg·L-1)24-表油菜素内酯(EBR)对茶树叶片叶绿素含量、气孔开度、光合气体交换参数及其相关基因表达的影响。结果表明,处理后第一天,叶面喷施0.10、0.30 mg·L-1 EBR显著增加了茶树叶片叶绿素含量,与对照相比,分别增加了38.89%、22.22%。处理后第三天和第五天,0.10、0.30 mg·L-1 EBR处理的茶树叶片气孔开度显著升高。处理后第一天和第五天,喷施EBR显著提高了茶树叶片的净光合速率。同时,EBR处理能显著上调BR合成酶基因、碳同化关键酶基因、叶绿素合成关键酶基因的表达。综上,外源EBR通过调控相关基因表达调节茶树叶片叶绿素含量、气孔开度,进而提高茶树叶片的光合作用能力。

With tea plant cultivar‘Zhongcha 108’as the test material,the effects of spraying EBR with different concentrations(0.10,0.30,0.50 mg·L-1)on the chlorophyll content,stomatal aperture,photosynthetic gas exchange parameters and related gene expression of tea leaves were studied.The results show that spraying 0.10 and 0.30 mg·L-1 EBR on leaves significantly increased the chlorophyll content of tea leaves on the first day after treatment.Compared with the control condition,chlorophyll content increased by 38.89%and 22.22%,respectively.On the third and fifth days after treatment,the stomatal aperture of tea leaves treated with 0.10 and 0.30 mg·L-1 EBR increased significantly.On the first and fifth days after treatment,spraying EBR significantly increased the net photosynthetic rate of tea leaves.At the same time,EBR treatment could significantly up-regulate the expressions of genes involved in BR biosynthesis,chlorophyll biosynthesis,and carbon assimilation.These results indicate that exogenous EBR increased the chlorophyll content and stomata aperture of tea leaves by regulating the expression of related genes,which ultimately promoted the photosynthetic rate of tea plants.