Light induces peroxisome proliferation in Arabidopsis seedlings through the photoreceptor phytochrome A, the transcription factor HY5HOMOLOG, and the peroxisomal protein PEROXIN11b
Light induces peroxisome proliferation in Arabidopsis seedlings through the photoreceptor phytochrome A, the transcription factor HY5HOMOLOG, and the peroxisomal protein PEROXIN11b
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DOI：
10.1104/pp.107.113555
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发表时间：
2008-03-01
期刊：
影响因子：
7.4
通讯作者：
Hu, Jianping
中科院分区：
文献类型：
--
作者：
Desai, Mintu;Hu, Jianping
过氧化物酶体是单膜分隔的亚细胞细胞器，在几乎所有真核生物中进行许多重要的代谢反应。过氧化物酶体会根据环境因素改变其形态、丰度和酶成分，但对其潜在机制知之甚少。在这项工作中，我们研究了光在拟南芥（Arabidopsis thaliana）过氧化物酶体增殖中的调节作用。我们提供的证据表明，光会诱导拟南芥幼苗中过氧化物酶体的增殖，并且过氧化物酶体蛋白 PEX11b 在介导这一过程中发挥着重要作用。远红光受体光敏色素 A (phyA) 和 bZIP 转录因子 HY5 HOMOLOG (HYH) 都是 PEX11b 在光下上调所必需的。我们进一步证明 phyA 和 hyh 突变体表现出过氧化物酶体丰度降低，这种表型可以通过在这些植物中过表达 PEX11b 来挽救。 HYH 蛋白能够与 PEX11b 的启动子结合，表明 PEX11b 基因是 HYH 的直接靶标。我们得出结论，HYH 和 PEX11b 构成了 phyA 介导的光信号级联的一个新分支，在幼苗光形态发生过程中促进过氧化物酶体增殖。
Peroxisomes are single membrane-delimited subcellular organelles that carry out numerous vital metabolic reactions in nearly all eukaryotes. Peroxisomes alter their morphology, abundance, and enzymatic constituents in response to environmental cues, yet little is known about the underlying mechanisms. In this work, we investigated the regulatory role of light in peroxisome proliferation in Arabidopsis (Arabidopsis thaliana). We provide evidence that light induces proliferation of peroxisomes in Arabidopsis seedlings and that the peroxisomal protein PEX11b plays an important role in mediating this process. The far-red light receptor phytochrome A (phyA) and the bZIP transcription factor HY5 HOMOLOG (HYH) are both required for the upregulation of PEX11b in the light. We further demonstrate that the phyA and hyh mutants exhibit reduced peroxisome abundance, a phenotype that can be rescued by overexpressing PEX11b in these plants. The HYH protein is able to bind to the promoter of PEX11b, suggesting that the PEX11b gene is a direct target of HYH. We conclude that HYH and PEX11b constitute a novel branch of the phyA-mediated light signaling cascade, which promotes peroxisome proliferation during seedling photomorphogenesis.