Manipulation of DET1 expression in tomato results in photomorphogenic phenotypes caused by post-transcriptional gene silencing
Manipulation of DET1 expression in tomato results in photomorphogenic phenotypes caused by post-transcriptional gene silencing
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DOI：
10.1111/j.1365-313x.2004.02218.x
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发表时间：
2004-11-01
期刊：
影响因子：
7.2
通讯作者：
Bowler, C
中科院分区：
文献类型：
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作者：
Davuluri, GR;Tuinen, A;Bowler, C
番茄高色素-2基因编码拟南芥核蛋白DE-黄化蛋白1(DET1)的同源基因。遗传分析表明，DET1是光信号转导的负调控因子，最近的研究结果表明，它可能在染色质重构的水平上调控光调控基因的表达。为了进一步了解DET1在植物发育过程中的功能，我们构建了一系列过表达载体并将它们导入番茄。出乎意料的是，我们只观察到了DET1失活的表型特征，即对光的高反应性。分子分析表明，在所有病例中，这些表型都是由于转录后基因沉默而抑制内源性DET1表达的结果。当DET1沉默发生在植物发育的相对早期阶段时，通常是致命的，而当沉默发生在随后的阶段时，获得了轻微的高反应表型。表型的出现与siRNAs的产生有关，但与DNA超甲基化无关，当使用带有DET1编码序列突变的构建体或仅包含基因3‘末端部分的构建体时，表型的出现最有效。这些结果表明DET1在植物发育过程中起着重要的作用，并表明DET1在水果中的沉默导致类胡萝卜素的增加，这可能具有生物技术潜力。
The tomato HIGH PIGMENT-2 gene encodes an orthologue of the Arabidopsis nuclear protein DE-ETIOLATED 1 (DET1). From genetic analyses it has been proposed that DET1 is a negative regulator of light signal transduction, and recent results indicate that it may control light-regulated gene expression at the level of chromatin remodelling. To gain further understanding about the function of DET1 during plant development, we generated a range of overexpression constructs and introduced them into tomato. Unexpectedly, we only observed phenotypes characteristic of DET1 inactivation, i.e. hyper-responsiveness to light. Molecular analysis indicated in all cases that these phenotypes were a result of suppression of endogenous DET1 expression, due to post-transcriptional gene silencing. DET1 silencing was often lethal when it occurred at relatively early stages of plant development, whereas light hyper-responsive phenotypes were obtained when silencing occurred later on. The appearance of phenotypes correlated with the generation of siRNAs but not DNA hypermethylation, and was most efficient when using constructs with mutations in the DET1 coding sequence or with constructs containing only the 3'-terminal portion of the gene. These results indicate an important function for DET1 throughout plant development and demonstrate that silencing of DET1 in fruits results in increased carotenoids, which may have biotechnological potential.