基于叶绿体能量代谢解析澳洲坚果光合作用对高温胁迫的分子生理响应机制

高温下部分澳洲坚果品种的叶片发生黄化，落果率增加，严重影响了产量。前期研究表明：黄化叶片的ATP含量与能荷水平增加，其光合速率却降低。为了深入探讨高温下叶绿体ATP供应能力与光合速率的关系，本研究拟以耐热品种“H2”和热敏感品种“HAES344”为试材，通过比较不同高温气候类型与模拟高温胁迫处理，并结合外源化学物质处理，观察叶绿体超微结构和ROS组织化学分布的变化，研究类囊体膜的脂肪酸组成及其调控基因表达变化，着重研究光系统、电子传递系统和ATPase的活性及其相关基因表达的变化，分析叶绿体ATP供应能力的变化及其对Rubisco与RCA活性以及光合速率的影响，以期明确高温胁迫下光合机构稳定性、光系统活性和光合电子传递能力的变化，探明叶绿体ATP合成的调控机制及其对光合碳同化的影响，从光合能量代谢的角度解析澳洲坚果光合作用对高温胁迫的分子生理响应机制，为澳洲坚果抗高温栽培生产奠定理论基础。

Under high temperature, the etiolation leaves of some macadamia varieties occurred and then the rate of fruit abscission increased, which seriously affected the yield. Previous studies showed that the levels of ATP and energy charge in the etiolation leaves increased, but the photosynthetic rate decreased. In order to further explore the relationship between the chloroplast ATP supply capacity and the photosynthetic rate under high temperature, this study will use the heat-tolerant cultivar of ‘H2’ and heat-sensitive cultivar of ‘HAES344’ as test materials, to observe the changes in the chloroplast ultrastructure and the histochemical distribution of ROS, to study the changes in the fatty acid composition of thylakoid membrane and the expressions of its regulatory genes, to focus on the research on the changes in the activities of photosystem, electron transport system and ATPase and the transcriptional levels of its related genes, and to analyze the change of chloroplast ATP supply capacity and its effect on the activities of Rubisco and RCA and the photosynthetic rate, through comparing the treatments of the different high temperature weather and the simulated high temperature stress and then combining with the exogenous chemicals treatments. It might contribute to understanding the changes in the photosynthetic apparatus stability, photosystem activity and photosynthetic electron transport capacity under high temperature stress, revealing the regulatory mechanism of chloroplast ATP synthesis and its influence on photosynthetic carbon assimilation, and elucidating the physiological and molecular mechanism of macadamia leaf photosynthesis in response to high temperature stress from the perspective of photosynthetic energy metabolism. This project will lay a theoretical foundation for guiding the macadamia production resistant to high temperature.