Tight relationship between two photosystems is robust in rice leaves under various nitrogen conditions
Tight relationship between two photosystems is robust in rice leaves under various nitrogen conditions
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在不同氮条件下，水稻叶片中两个光系统之间的紧密关系是牢固的
DOI：
10.1007/s10265-022-01431-7
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发表时间：
2022
影响因子：
2.8
通讯作者：
Noguchi Ko
中科院分区：
文献类型：
--
作者：
Ozaki Hiroshi;Mizokami Yusuke;Sugiura Daisuke;Sohtome Takayuki;Miyake Chikahiro;Sakai Hidemitsu;Noguchi Ko
叶片氮素水平不仅影响光合co2同化，还影响光合电子传递的两个光系统。光系统II的量子产率[Y(II)]和由于光系统I的供体侧限制而产生的非光化学产率[Y(ND)]，即氧化P700 （P700+）占总P700的比例，随着叶片N水平的变化而相反变化，并且这两个参数之间的负相关关系已经报道在不同N水平的生长室内栽培的植物叶片中。本研究旨在阐明叶片氮水平短期变化后，这种相关性是否维持，以及在田间条件下，哪些参数对叶片氮水平变化的响应最大。在稻田中栽培了不同施氮水平的水稻品种，对低施氮条件下的水稻进行了额外施氮处理，并测量了成熟叶片两种光系统的参数。低氮条件下，水稻叶片Y（ND）增加，光合线性电子流受到抑制。在这种情况下，P700+的积累可以起到多余能量耗散的作用。添加N后，Y（ND）和Y（II）均发生变化，并保持负相关关系。我们使用了一种新开发的装置来评估光系统。该装置检测了氮素添加后植株Y（ND）的相似变化，并观察到不同氮素条件下植株Y（ND）与光合o2进化速率呈负相关。本研究提供了强有力的田间证据，表明Y（ND）在很大程度上取决于叶片氮水平的变化，并且与叶片氮水平、品种和年变化无关，Y（II）和Y（ND）呈负相关。在田间条件下，Y（ND）能稳定地监测叶片氮态和线性电子流。
Leaf nitrogen (N) level affects not only photosynthetic CO2assimilation, but also two photosystems of the photosynthetic electron transport. The quantum yield of photosystem II [Y(II)] and the non-photochemical yield due to the donor side limitation of photosystem I [Y(ND)], which denotes the fraction of oxidized P700 (P700+) to total P700, oppositely change depending on leaf N level, and the negative correlation between these two parameters has been reported in leaves of plants cultivated at various N levels in growth chambers. Here, we aimed to clarify whether this correlation is maintained after short-term changes in leaf N level, and what parameters are the most responsive to the changes in leaf N level under field conditions. We cultivated rice varieties at two N fertilization levels in paddy fields, treated additional N fertilization to plants grown at low N, and measured parameters of two photosystems of mature leaves. In rice leaves under low N condition, the Y(ND) increased and the photosynthetic linear electron flow was suppressed. In this situation, the accumulation of P700+can function as excess energy dissipation. After the N addition, both Y(ND) and Y(II) changed, and the negative correlation between them was maintained. We used a newly-developed device to assess the photosystems. This device detected the similar changes in Y(ND) after the N addition, and the negative correlation between Y(ND) and photosynthetic O2evolution rates was observed in plants under various N conditions. This study has provided strong field evidence that the Y(ND) largely changes depending on leaf N level, and that the Y(II) and Y(ND) are negatively correlated with each other irrespective of leaf N level, varieties and annual variation. The Y(ND) can stably monitor the leaf N status and the linear electron flow under field conditions.