《植物生理学报》 2018, 54(6): 1045-1054

黄瓜叶片发育过程中光合机构活性与其核心蛋白表达的关系

钟昕^1,2, 李玉婷^1,3, 车兴凯^1,3, 张子山^1,3, 刘彬彬¹, 李清明^1,2,4,*, 高辉远^1,3,*

¹作物生物学国家重点实验室, 山东泰安271018; ²山东农业大学园艺科学与工程学院, 山东泰安271018; ³山东农业大学生命科学学院, 山东泰安271018; ⁴农业部黄淮海设施农业工程科学观测实验站, 山东泰安271018

通信作者：李清明；E-mail: gslqm@sdau.edu.cn, gaohy@sdau.edu.cn

摘　要：

本实验研究了黄瓜叶片展开过程中, 光系统I (PSI)、光系统II (PSII)核心蛋白PsaA和D1以及卡尔文循环关键酶核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)的表达和PSI、PSII及卡尔文循环的发育速度快慢以及它们与光合速率的关系。PSI、PSII的活性、羧化效率(CE)和光合作用核心蛋白的表达量都随着叶片的展开而逐渐升高, 但是幼叶中PSII活性的完善要显著早于PSI活性的完善, 表现为与成熟叶相比, 幼叶的PSII活性F_m-F_o、PSII最大光化学效率F_v/F_m、单位叶片截面积PSII有活性反应中心数目RC/CS_o等均大于幼叶的PSI最大氧化还原活性ΔI/I_o; PSII核心蛋白D1的相对表达量也显著高于PSI核心蛋白PsaA的相对表达量。此外, 虽然在幼叶中, 卡尔文循环关键酶Rubisco的相对表达量高于PSI和PSII核心蛋白的相对表达量, 但是幼叶的CE却很低, 这说明光合作用核心蛋白的表达量与光合机构的活性并不成正比关系。综合分析表明, 幼叶较低的CE是幼叶发育过程中光合作用的主要限制因素。

关键词：黄瓜; 叶片发育; 光合作用核心蛋白; OJIP test; PSI和PSII

收稿：2018-01-05   修定：2018-05-23

资助：国家自然科学基金(31471918、31701966、31771691)、山东省自然科学基金(ZR2013CM008)和国家科技支撑计划(2014BAD05B03)。

The relationship between the activities of photosynthetic apparatus and the expressions of photosynthetic core proteins during the leaf expansion of Cucumis sativus

ZHONG Xin^1,2, LI Yu-Ting^1,3, CHE Xing-Kai^1,3, ZHANG Zi-Shan^1,3, LIU Bin-Bin¹, LI Qing-Ming^1,2,4,*, GAO Hui-Yuan^1,3,*

¹State Key Laboratory of Crop Biology, Taian, Shandong 271018, China; ²College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong 271018, China; ³College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China; ⁴Scientific Observing and Experimental Station of Environment Controlled Agricultural Engineering in Huang-Huai-Hai Region, Ministry of Agriculture, Taian, Shandong 271018, China

Corresponding author: LI Qing-Ming; E-mail: gslqm@sdau.edu.cn, gaohy@sdau.edu.cn

Abstract:

This study explored the relationship between the expressions of photosystem I (PSI), photosystem II (PSII) core proteins PsaA, D1 and the key enzyme of Calvin cycle ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), development activities of PSI, PSII, Calvin cycle and photosynthetic rate during the development of Cucumis sativus leaves. The results showed that the activities of PSI and PSII, carboxylation efficiency (CE) and the expressions of photosynthetic apparatus core proteins increased with the leaf expansion, but the development speed of the PSII activity in the youngest initiating leaf was significantly greater than that of PSI, which was supported by the observation that the relative PSII activity F_m-F_o, PSII maximum photochemical efficiency F_v/F_m, active reaction centers per leaf cross section RC/CS_o and so on were much higher than that of PSI maximum redox activity ΔI/I_o. In addition, the relative expression of PSII core protein (D1) was also significantly higher than PSI core protein (PsaA) in youngest initiating leaves. Although the relative expression of Calvin cycle key enzyme Rubisco was higher than that of PSI and PSII core proteins in youngest initiating leaves, the CE was still very low. It demonstrated that the expression extent of the photosynthetic-apparatuscore-proteins was not positively correlated with the photosynthetic rate. Through comprehensive analysis, we suggest that the CE is the main limiting factor of photosynthetic rate in the youngest initiating leaves during the leaf development of cucumber.

Key words: cucumber (Cucumis sativus); leaf development; photosynthesis core protein; OJIP test; PSI and PSII