Dynamic seasonal changes in photosynthesis systems in leaves of Asarum tamaense, an evergreen understorey herbaceous species
Dynamic seasonal changes in photosynthesis systems in leaves of Asarum tamaense, an evergreen understorey herbaceous species
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常绿林下草本植物细辛叶片光合作用系统的动态季节变化
DOI：
10.1093/aob/mcac156
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发表时间：
2023
期刊：
影响因子：
4.2
通讯作者：
Ko Noguchi
中科院分区：
文献类型：
--
作者：
Naoki Wada;Issei Kondo;Ryouichi Tanaka;Junko Kishimoto;Atsuko Miyagi;Maki Kawai-Yamada;Yusuke Mizokami;Ko Noguchi
研究背景与目的落叶林林下常绿草本植物在动态的光、温季节变化下维持其长寿叶的光系统。然而，在常绿林下草本植物，它是未知的光合电子传递如何适应森林林下环境的季节变化，以及什么样的光保护系统的功能，在过度的能量耗散下，高光和低温environment.MethodsHere，我们usedAsarum tamaense，常绿草本植物在落叶林林下具有单冲洗和长寿的叶子，并测定了全年叶片光合CO2同化和电子传递。结果表明，在饱和光下，夏、秋、冬两季，冬小麦叶片CO2同化率和电子传递率均较低，而秋、冬两季则有所上升。tamaenseleaves。虽然Rubisco等光合蛋白质含量在秋冬季节没有增加，但类囊体膜质子动力势和跨膜pH值在夏季较高，从夏季到冬季有较大幅度的下降。这些减少缓解了管腔酸化的抑制，并增加了冬季的电子传递速率。类胡萝卜素的含量和组成具有季节性变化，这可能会影响非光化学猝灭从夏季到冬季的变化。冬季叶片积累脯氨酸和苹果酸，这可能支持冷驯化。tamaenseleae，冬季光合电子传递速率的增加不是由于光合酶含量的增加，而是由于光合酶的激活和/或光合电子流限制的释放。这些季节性变化的电子传递的调节，也在几个光保护系统的变化，应支持全年动态环境变化下的光合碳增益的驯化。
Background and AimsEvergreen herbaceous species in the deciduous forest understorey maintain their photosystems in long-lived leaves under dynamic seasonal changes in light and temperature. However, in evergreen understorey herbs, it is unknown how photosynthetic electron transport acclimates to seasonal changes in forest understorey environments, and what photoprotection systems function in excess energy dissipation under high-light and low-temperature environments in winter.MethodsHere, we usedAsarum tamaense, an evergreen herbaceous species in the deciduous forest understorey with a single-flush and long-lived leaves, and measured photosynthetic CO2assimilation and electron transport in leaves throughout the year. The contents of photosynthetic proteins, pigments and primary metabolites were determined from regularly collected leaves.Key resultsBoth the rates of CO2assimilation and electron transport under saturated light were kept low in summer, but increased in autumn and winter inA. tamaenseleaves. Although the contents of photosynthetic proteins including Rubisco did not increase in autumn and winter, the proton motive force and ΔpH across the thylakoid membrane were high in summer and decreased from summer to winter to a great extent. These decreases alleviated the suppression by lumen acidification and increased the electron transport rate in winter. The content and composition of carotenoids changed seasonally, which may affect changes in non-photochemical quenching from summer to winter. Winter leaves accumulated proline and malate, which may support cold acclimation.ConclusionsInA. tamaenseleaves, the increase in photosynthetic electron transport rates in winter was not due to an increase in photosynthetic enzyme contents, but due to the activation of photosynthetic enzymes and/or release of limitation of photosynthetic electron flow. These seasonal changes in the regulation of electron transport and also the changes in several photoprotection systems should support the acclimation of photosynthetic C gain under dynamic environmental changes throughout the year.