Silencing of the violaxanthin de-epoxidase gene in the diatom Phaeodactylum tricornutum reduces diatoxanthin synthesis and non-photochemical quenching.
Silencing of the violaxanthin de-epoxidase gene in the diatom Phaeodactylum tricornutum reduces diatoxanthin synthesis and non-photochemical quenching.
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DOI：
10.1371/journal.pone.0036806
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Kroth PG
中科院分区：
文献类型：
--
作者：
Lavaud J;Materna AC;Sturm S;Vugrinec S;Kroth PG
硅藻是初级生产者的一个主要群体，在所有水生生态系统中无处不在。为了保护自己免受光氧化损伤，在一个波动的光气候可能与定期过量的光暴露，硅藻已经开发了几种光保护机制。叶黄素循环（XC）依赖的非光化学叶绿素荧光猝灭（NPQ）是硅藻最重要的光保护过程之一。NPQ取决于紫黄质脱环氧酶（VDE）（也称为DD脱环氧酶（DDE））将硅藻黄素（DD）转化为硅藻黄素（DT）。为了研究DDE在控制NPQ中的作用，我们产生了三角褐指藻的转化体，其中编码DDE的基因（Vde/Dde）被沉默。通过用含有短（198 bp）或长（523 bp）反义（AS）片段的质粒或用介导自身互补发夹样构建体（反向重复序列，IR）表达的质粒对细胞进行遗传转化来诱导RNA干扰。沉默方法产生具有与野生型（WT）细胞明显可区分的表型的硅藻转化体，即DD脱环氧化和NPQ诱导的程度较低以及动力学较慢。基于实时PCR的Dde转录物的定量揭示了AS转化体和WT细胞之间以及AS和IR转化体之间的转录物水平的差异，表明可能存在两种不同的基因沉默介导机制。这通过光强度对两种类型的转化体的各自沉默效率的差异效应来证实。转化体的表征加强了XC和NPQ的一些具体特征，并证实了硅藻DT/NPQ关系的最新机理模型。
Diatoms are a major group of primary producers ubiquitous in all aquatic ecosystems. To protect themselves from photooxidative damage in a fluctuating light climate potentially punctuated with regular excess light exposures, diatoms have developed several photoprotective mechanisms. The xanthophyll cycle (XC) dependent non-photochemical chlorophyll fluorescence quenching (NPQ) is one of the most important photoprotective processes that rapidly regulate photosynthesis in diatoms. NPQ depends on the conversion of diadinoxanthin (DD) into diatoxanthin (DT) by the violaxanthin de-epoxidase (VDE), also called DD de-epoxidase (DDE). To study the role of DDE in controlling NPQ, we generated transformants of P. tricornutum in which the gene (Vde/Dde) encoding for DDE was silenced. RNA interference was induced by genetic transformation of the cells with plasmids containing either short (198 bp) or long (523 bp) antisense (AS) fragments or, alternatively, with a plasmid mediating the expression of a self-complementary hairpin-like construct (inverted repeat, IR). The silencing approaches generated diatom transformants with a phenotype clearly distinguishable from wildtype (WT) cells, i.e. a lower degree as well as slower kinetics of both DD de-epoxidation and NPQ induction. Real-time PCR based quantification of Dde transcripts revealed differences in transcript levels between AS transformants and WT cells but also between AS and IR transformants, suggesting the possible presence of two different gene silencing mediating mechanisms. This was confirmed by the differential effect of the light intensity on the respective silencing efficiency of both types of transformants. The characterization of the transformants strengthened some of the specific features of the XC and NPQ and confirmed the most recent mechanistic model of the DT/NPQ relationship in diatoms.
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影响因子：
4.3
作者：
Goss, Reimund;Pinto, Elizabeth Ann;Richter, Michael
通讯作者：
Richter, Michael
影响因子：
2.8
作者：
GUILLARD, RR;RYTHER, JH
通讯作者：
RYTHER, JH
DOI：
10.1016/0022-0981(88)90043-3
发表时间：
1988-01-01
影响因子：
2
作者：
CARON, L;MORTAINBERTRAND, A;JUPIN, H
通讯作者：
JUPIN, H
影响因子：
6.4
作者：
Gisselsson, A;Szilágyi, A;Åkerlund, HE
通讯作者：
Åkerlund, HE
影响因子：
2.5
作者：
de Poll, Willem H. van;Lagunas, Marcos;Buma, Anita G. J.
通讯作者：
Buma, Anita G. J.