The roles of Arabidopsis proteins of Lhcb4, Lhcb5 and Lhcb6 in oxidative stress under natural light conditions
The roles of Arabidopsis proteins of Lhcb4, Lhcb5 and Lhcb6 in oxidative stress under natural light conditions
复制标题
自然光条件下拟南芥Lhcb4、Lhcb5和Lhcb6蛋白在氧化应激中的作用
DOI：
10.1016/j.plaphy.2018.07.014
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发表时间：
2018-09-01
影响因子：
6.5
通讯作者：
Yuan, Shu
中科院分区：
文献类型：
--
作者：
Chen, Yang-Er;Ma, Jie;Yuan, Shu
在光条件下，光系统的天线系统和反应中心会产生高活性的氧物种(ROS)。Lhcb4(CP29)、Lhcb5(CP26)和Lhcb6(CP24)这三种次要的叶绿素结合天线蛋白在光抑制过程中的保护作用已经得到了很好的研究。然而，它们在自然光条件下对氧化损伤的调控机制仍不清楚。在这里，我们以田间条件下生长的拟南芥基因敲除系为材料，研究了它们在氧化胁迫反应和光合作用适应中的特殊作用。三个突变系都表现出从捕光复合体II(LHCII)到PSII反应中心的能量转移效率降低。缺乏Lhcb4(KoLHCB4)和Lhcb6(KoLHCB6)的植物放氧能力略有下降。田间种植的缺Lhcb5和缺Lhcb6植株的光合作用速率和适合度受到影响，但不影响缺Lhcb4植株的光合作用。抗氧化剂分析表明，缺Lhcb6植株的抗氧化酶活性和非酶类抗氧化剂水平最低。此外，KoLHCB6植株积累了更高水平的超氧化物和氢，在田间遭受了更严重的氧化损伤。我们的结果清楚地表明，Lhcb6可能参与了在自然条件下减轻氧化应激和光保护的作用。
Under light conditions, highly reactive oxygen species (ROS) can be generated in the antenna systems and the reaction center of photosystems (PS). The protective roles of Lhcb4 (CP29), Lhcb5 (CP26) and Lhcb6 (CP24), three minor chlorophyll binding antenna proteins during photoinhibition have been well studied. However, their regulatory mechanisms against oxidative damages under natural light conditions remain unknown. Here we investigated their specific roles in oxidative stress responses and photosynthetic adaptation by using the Arabidopsis thaliana knockout lines grown in the field condition. All three mutant lines exhibited decreased energy-transfer efficiency from the LHCII (light-harvesting complex II) to the PSII reaction center. Oxygen evolution capacity decreased slightly in the plants lacking Lhcb4 (koLHCB4) and Lhcb6 (koLHCB6). Photosynthetic rates and fitness for the plants lacking Lhcb5 (koLHCB5) or koLHCB6 grown in the field were affected, but not in the plants lacking Lhcb4, Antioxidant analysis indicated the lowest antioxidant enzyme activities and the lowest levels of non-enzymatic antioxidants in koLHCB6 plants. In addition, koLHCB6 plants accumulated much higher levels of superoxide and hydrogen, and suffered more severe oxidative-damages in the field. Our results clearly demonstrate that Lhcb6 may be involved in alleviating oxidative stress and photo protection under natural conditions.