Integrated temporal regulation of the photorespiratory pathway.: Circadian regulation of two arabidopsis genes encoding serine hydroxymethyltransferase
Integrated temporal regulation of the photorespiratory pathway.: Circadian regulation of two arabidopsis genes encoding serine hydroxymethyltransferase
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DOI：
10.1104/pp.123.1.381
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发表时间：
2000-05-01
期刊：
影响因子：
7.4
通讯作者：
Salomé, PA
中科院分区：
文献类型：
--
作者：
McClung, CR;Hsu, M;Salomé, PA
光呼吸途径由位于三个不同细胞隔室中的酶组成：叶绿体、过氧化物酶体和线粒体。光呼吸酶由核基因编码，在胞质溶胶中翻译，并靶向这些不同的亚细胞区室，一种可能的手段，通过其调节编码光呼吸酶的基因的表达是协调的时间控制。我们以前已经表明，在拟南芥中，昼夜节律钟调节编码叶绿体（Rubisco小亚基和Rubisco活化酶）和过氧化物酶体（过氧化氢酶）的光呼吸途径的组成部分的核基因的表达。为了确定生物钟是否也调节表达：编码光呼吸途径线粒体组分的基因，我们表征了拟南芥丝氨酸羟甲基转移酶（SHM）基因家族。我们研究了这些家族成员中的两个成员的mRNA积累，包括一个可能的光呼吸基因（SHM1）和第二个在根中最大表达的基因（SHM4），并表明两者都表现出与其他光呼吸基因所描述的mRNA丰度的昼夜节律振荡。此外，我们表明，SHM1 mRNA积累在光生长的幼苗，虽然这种反应可能是一个间接的结果，诱导光合作用和光呼吸的照明。
The photorespiratory pathway is comprised of enzymes localized within three distinct cellular compartments: chloroplasts, peroxisomes, and mitochondria. Photorespiratory enzymes are encoded by nuclear genes, translated in the cytosol, and targeted into these distinct subcellular compartments, One likely means by which to regulate the expression of the genes encoding photorespiratory enzymes is coordinated temporal control. We have previously shown in Arabidopsis that a circadian clock regulates the expression of the nuclear genes encoding both chloroplastic (Rubisco small subunit and Rubisco activase) and peroxisomal (catalase) components of the photorespiratory pathway. To determine whether a circadian clock also regulates the expression of: genes encoding mitochondrial components of the photorespiratory pathway, we characterized a family of Arabidopsis serine hydroxymethyltransferase (SHM) genes. We examined mRNA accumulation for two of these family members, including one probable photorespiratory gene (SHM1) and a second gene expressed maximally in roots (SHM4), and show that both exhibit circadian oscillations in mRNA abundance that are in phase with those described for other photorespiratory genes. In addition, we show that SHM1 mRNA accumulates in light-grown seedlings, although this response is probably an indirect consequence of the induction of photosynthesis and photorespiration by illumination.