The diatom Phaeodactylum tricornutum adjusts nonphotochemical fluorescence quenching capacity in response to dynamic light via fine-tuned Lhcx and xanthophyll cycle pigment synthesis
The diatom Phaeodactylum tricornutum adjusts nonphotochemical fluorescence quenching capacity in response to dynamic light via fine-tuned Lhcx and xanthophyll cycle pigment synthesis
复制标题
三角褐指藻通过微调Lhcx和叶黄素循环色素合成来调节非光化学荧光猝灭能力以响应动态光
DOI：
10.1111/nph.14337
复制
发表时间：
2017-04-01
期刊：
影响因子：
9.4
通讯作者：
Lavaud, Johann
中科院分区：
文献类型：
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作者：
Lepetit, Bernard;Gelin, Gautier;Lavaud, Johann
硅藻含有高度灵活的能力，通过非光化学荧光猝灭（NPQ）消散过度吸收的光，该荧光猝灭（NPQ）基于硅藻黄素（Dd）到硅藻黄素（Dt）的光诱导转化和Lhcx蛋白的存在。我们研究了三角褐指藻（Phaeodactylum tricornutum）在从连续弱光到3d正弦（SL）或波动（FL）光照条件变化后，Dd + Dt数量、Lhcx基因和蛋白质合成以及NPQ能力的变化。由于Lhcx 1的表达不同，导致NPQ能力不同的四个三角褐指藻菌株均对动态光照产生响应，而与初始NPQ能力无关。在SL期间，由于Lhcx 2和Dd + Dt量的逐渐增加，NPQ容量强烈增强。在FL期间，由于增加的Dd + Dt、Lhcx 2和Lhcx 3，细胞在第一天增强了它们的NPQ能力;已经由第二天光适应完成。虽然在SL条件下Dt的猝灭效率大大降低，但在整个FL暴露过程中Dt的猝灭效率仍然很高。我们的研究结果表明，与SL条件下相比，FL条件下三角褐指藻的光适应策略更加平衡和经济。
Diatoms contain a highly flexible capacity to dissipate excessively absorbed light by nonphotochemical fluorescence quenching (NPQ) based on the light-induced conversion of diadinoxanthin (Dd) into diatoxanthin (Dt) and the presence of Lhcx proteins. Their NPQ fine regulation on the molecular level upon a shift to dynamic light conditions is unknown.We investigated the regulation of Dd + Dt amount, Lhcx gene and protein synthesis and NPQ capacity in the diatom Phaeodactylum tricornutum after a change from continuous low light to 3 d of sine (SL) or fluctuating (FL) light conditions. Four P. tricornutum strains with different NPQ capacities due to different expression of Lhcx1 were included.All strains responded to dynamic light comparably, independently of initial NPQ capacity. During SL, NPQ capacity was strongly enhanced due to a gradual increase of Lhcx2 and Dd + Dt amount. During FL, cells enhanced their NPQ capacity on the first day due to increased Dd + Dt, Lhcx2 and Lhcx3; already by the second day light acclimation was accomplished. While quenching efficiency of Dt was strongly lowered during SL conditions, it remained high throughout the whole FL exposure.Our results highlight a more balanced and cost-effective photoacclimation strategy of P. tricornutum under FL than under SL conditions.