Different molecular bases underlie the mitochondrial respiratory activity in the homoeothermic spadices of Symplocarpus renifolius and the transiently thermogenic appendices of Arum maculatum.
Different molecular bases underlie the mitochondrial respiratory activity in the homoeothermic spadices of Symplocarpus renifolius and the transiently thermogenic appendices of Arum maculatum.
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DOI：
10.1042/bj20111978
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发表时间：
2012-07-15
期刊：
影响因子：
--
通讯作者：
Ito K
中科院分区：
文献类型：
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作者：
Kakizaki Y;Moore AL;Ito K
我们知道，重叶合果（Symplocarpus renifolius）和斑芋（Arum maculatum）在其花发育过程中产生大量的热量，但它们使用不同的调节机制，即同温生热与瞬时产热。为了进一步阐明植物种特异性产热机制的分子基础，本研究分析了金针兰和黄斑金针兰线粒体呼吸组分的天然结构和表达模式。我们利用Blue native PAGE结合纳米液相色谱-质谱联用（nano LC - liquid chromatography -MS/MS，串联质谱）进行对比分析，发现两种植物的呼吸复合物成分基本相似，但一些线粒体成分在它们的产热器官中表达不同。即，在S. renifolius中检测到复合物II为340 kDa的产物，表明其在体内具有低聚物或超分子结构。此外，研究还发现，黄斑楠的外源NAD(P)H脱氢酶的表达量高于白斑楠，而两种植物的内源NAD(P)H脱氢酶的表达量基本相同。在这两个物种中，替代氧化酶被检测到在第一维上被拉长的涂片样信号，其峰值在200 kDa左右。从植物体温调节的角度讨论了这些数据的意义和意义。
Symplocarpus renifolius and Arum maculatum are known to produce significant heat during the course of their floral development, but they use different regulatory mechanisms, i.e. homoeothermic compared with transient thermogenesis. To further clarify the molecular basis of species-specific thermogenesis in plants, in the present study we have analysed the native structures and expression patterns of the mitochondrial respiratory components in S. renifolius and A. maculatum. Our comparative analysis using Blue native PAGE combined with nano LC (liquid chromatography)-MS/MS (tandem MS) has revealed that the constituents of the respiratory complexes in both plants were basically similar, but that several mitochondrial components appeared to be differently expressed in their thermogenic organs. Namely, complex II in S. renifolius was detected as a 340 kDa product, suggesting an oligomeric or supramolecular structure in vivo. Moreover, the expression of an external NAD(P)H dehydrogenase was found to be higher in A. maculatum than in S. renifolius, whereas an internal NAD(P)H dehydrogenase was expressed at a similar level in both species. Alternative oxidase was detected as smear-like signals that were elongated on the first dimension with a peak at around 200 kDa in both species. The significance and implication of these data are discussed in terms of thermoregulation in plants.