Photosynthesis-dependent H(2)O(2) transfer from chloroplasts to nuclei provides a high-light signalling mechanism.
Photosynthesis-dependent H(2)O(2) transfer from chloroplasts to nuclei provides a high-light signalling mechanism.
复制标题
DOI：
10.1038/s41467-017-00074-w
复制
发表时间：
2017-06-29
影响因子：
16.6
通讯作者：
Mullineaux PM
中科院分区：
文献类型：
--
作者：
Exposito-Rodriguez M;Laissue PP;Yvon-Durocher G;Smirnoff N;Mullineaux PM
在适应波动光的过程中，叶绿体通过向细胞核发送信号来传递信息。已经提出了几种来自叶绿体的潜在操作信号，但没有一种被证明可以转移到细胞核来调节基因表达。一个被提出的信号是由叶绿体以光依赖的方式产生的过氧化氢（H2O2）。利用HyPer2（一种基因编码的H2O2荧光传感器），我们发现在光合作用的benthamiana表皮细胞中，暴露在强光下会增加叶绿体基质、细胞质和细胞核中H2O2的产生。关键的是，基质抗坏血酸过氧化物酶（H2O2清除剂）的过度表达或DCMU（光合作用抑制剂）处理会减弱细胞核H2O2的积累和高光响应基因的表达。胞质抗坏血酸过氧化物酶的过表达对细胞核H2O2积累和高光响应基因的表达影响不大。这是因为H2O2来自与细胞核密切相关的叶绿体亚群。因此，H2O2从叶绿体直接转移到细胞核，避开细胞质，使光合作用控制基因表达成为可能。多个质体衍生的信号已被提出，但没有显示移动到细胞核，以促进植物适应波动光。在这里，作者使用荧光过氧化氢传感器提供了H2O2直接从叶绿体转移到细胞核以控制核基因表达的证据。
Chloroplasts communicate information by signalling to nuclei during acclimation to fluctuating light. Several potential operating signals originating from chloroplasts have been proposed, but none have been shown to move to nuclei to modulate gene expression. One proposed signal is hydrogen peroxide (H2O2) produced by chloroplasts in a light-dependent manner. Using HyPer2, a genetically encoded fluorescent H2O2 sensor, we show that in photosynthetic Nicotiana benthamiana epidermal cells, exposure to high light increases H2O2 production in chloroplast stroma, cytosol and nuclei. Critically, over-expression of stromal ascorbate peroxidase (H2O2 scavenger) or treatment with DCMU (photosynthesis inhibitor) attenuates nuclear H2O2 accumulation and high light-responsive gene expression. Cytosolic ascorbate peroxidase over-expression has little effect on nuclear H2O2 accumulation and high light-responsive gene expression. This is because the H2O2 derives from a sub-population of chloroplasts closely associated with nuclei. Therefore, direct H2O2 transfer from chloroplasts to nuclei, avoiding the cytosol, enables photosynthetic control over gene expression. Multiple plastid-derived signals have been proposed but not shown to move to the nucleus to promote plant acclimation to fluctuating light. Here the authors use a fluorescent hydrogen peroxide sensor to provide evidence that H2O2 is transferred directly from chloroplasts to nuclei to control nuclear gene expression.