Rubisco activase is a key regulator of non-steady-state photosynthesis at any leaf temperature and, to a lesser extent, of steady-state photosynthesis at high temperature.
Rubisco activase is a key regulator of non-steady-state photosynthesis at any leaf temperature and, to a lesser extent, of steady-state photosynthesis at high temperature.
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DOI：
10.1111/j.1365-313x.2012.05041.x
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发表时间：
2012-09
期刊：
影响因子：
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通讯作者：
W. Yamori;Chisato Masumoto;H. Fukayama;A. Makino
中科院分区：
文献类型：
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作者：
W. Yamori;Chisato Masumoto;H. Fukayama;A. Makino
以野生型水稻和表达不同数量Rubisco活化酶的转基因水稻为材料，分析了Rubisco活化酶在稳态和非稳态光合作用中的作用。在25°C以下，只有当Rubisco活化酶降低超过70%时，Rubisco活化状态和稳态光合作用才会受到影响。然而，在40°C下，Rubisco活化酶含量的较小降低与Rubisco活化状态降低和稳态光合作用有关。因此，在水稻中过量表达玉米Rubisco活化酶不会导致Rubisco活化状态的增加，也不会导致光合速率在低于25°C时增加，但在40°C时具有小的刺激作用。另一方面，光合作用的速率接近稳定状态后，在光强度的增加是快速的Rubisco活化酶过表达的植物，中间的野生型，和最慢的反义植物在任何叶温。在Rubisco活化酶过表达的植物中，Rubisco活化状态在低光下保持在比野生型更高的水平。因此，在光强度增加之后通过Rubisco活化酶的快速调节和/或在低光下维持高Rubisco活化状态将导致在光强度增加之后Rubisco活化状态和光合速率的快速增加。Rubisco活化酶在任何叶温下的非稳态光合作用和高温下的稳态光合作用中起着重要的调节作用。
The role of Rubisco activase in steady-state and non-steady-state photosynthesis was analyzed in wild-type (Oryza sativa) and transgenic rice that expressed different amounts of Rubisco activase. Below 25°C, the Rubisco activation state and steady-state photosynthesis were only affected when Rubisco activase was reduced by more than 70%. However, at 40°C, smaller reductions in Rubisco activase content were linked to a reduced Rubisco activation state and steady-state photosynthesis. As a result, overexpression of maize Rubisco activase in rice did not lead to an increase of the Rubisco activation state, nor to an increase in photosynthetic rate below 25°C, but had a small stimulatory effect at 40°C. On the other hand, the rate at which photosynthesis approached the steady state following an increase in light intensity was rapid in Rubisco activase-overexpressing plants, intermediate in the wild-type, and slowest in antisense plants at any leaf temperature. In Rubisco activase-overexpressing plants, Rubisco activation state at low light was maintained at higher levels than in the wild-type. Thus, rapid regulation by Rubisco activase following an increase in light intensity and/or maintenance of a high Rubisco activation state at low light would result in a rapid increase in Rubisco activation state and photosynthetic rate following an increase in light intensity. It is concluded that Rubisco activase plays an important role in the regulation of non-steady-state photosynthesis at any leaf temperature and, to a lesser extent, of steady-state photosynthesis at high temperature.