Changes in Photosynthetic Electron Transport during Leaf Senescence in Two Barley Varieties Grown in Contrasting Growth Regimes
Changes in Photosynthetic Electron Transport during Leaf Senescence in Two Barley Varieties Grown in Contrasting Growth Regimes
复制标题
不同生长条件下生长的两个大麦品种叶片衰老过程中光合电子传输的变化
DOI：
10.1093/pcp/pcaa114
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发表时间：
2020
影响因子：
4.9
通讯作者：
Krieger-Liszkay Anja
中科院分区：
文献类型：
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作者：
Shimakawa Ginga;Roach Thomas;Krieger-Liszkay Anja
叶片衰老是植物将多种代谢物和营养物质重新动员到发育中的叶片、果实和种子等组织中的一个重要过程。已有研究表明，活性氧(ROS)在启动叶片衰老中起重要作用。两个不同大麦品种的旗叶。洛梅里特和cv.Carina，在叶绿素显著损失后，在衰老后期表现出不同的光系统损失和ROS的产生。在这里，我们研究了这两个品种在衰老早期初生叶的光合作用电子传递和ROS产生。对在自然光和温度下生长的植物与在弱光下生长在温控生长室中的植物进行了比较。用在体近红外吸收光谱和叶绿素荧光分析了光活性P700、铁氧还蛋白和藻蓝蛋白(PC)光合作用电子传递的变化，用自旋捕捉电子顺磁共振光谱测定了ROS。这两个品种之间的ROS产生的差异只在室外植物中观察到，而PC的损失在两个大麦品种中都是常见的，无论生长条件如何。我们认为，Pc的损失是叶片衰老的最早可检测到的光合作用参数，而个体ROS的产生差异发生得较晚，并取决于环境因素。
Leaf senescence is an important process for plants to remobilize a variety of metabolites and nutrients to sink tissues, such as developing leaves, fruits and seeds. It has been suggested that reactive oxygen species (ROS) play an important role in the initiation of leaf senescence. Flag leaves of two different barley varieties, cv. Lomerit and cv. Carina, showed differences in the loss of photosystems and in the production of ROS at a late stage of senescence after significant loss of chlorophyll . Here, we investigated photosynthetic electron transport and ROS production in primary leaves of these two varieties at earlier stages of senescence. Comparisons were made between plants grown outside in natural light and temperatures and plants grown in temperature-controlled growth chambers under low light intensity. Alterations in the content of photoactive P700, ferredoxin and plastocyanin (PC) photosynthetic electron transport were analyzed using in vivo near-infrared absorbance changes and chlorophyll fluorescence, while ROS were measured with spin-trapping electron paramagnetic resonance spectroscopy. Differences in ROS production between the two varieties were only observed in outdoor plants, whereas a loss of PC was common in both barley varieties regardless of growth conditions. We conclude that the loss of PC is the earliest detectable photosynthetic parameter of leaf senescence while differences in the production of individual ROS species occur later and depend on environmental factors.