A Specific Transcriptome Signature for Guard Cells from the C4 Plant Gynandropsis gynandra
A Specific Transcriptome Signature for Guard Cells from the C4 Plant Gynandropsis gynandra
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DOI：
10.1104/pp.15.01203
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发表时间：
2016-03-01
期刊：
影响因子：
7.4
通讯作者：
Genty, Bernard
中科院分区：
文献类型：
--
作者：
Aubry, Sylvain;Aresheva, Olga;Genty, Bernard
C-4光合作用代表了趋同进化的一个很好的例子，它导致了植物对碳和水的利用的优化。在C-4植物中，碳集中机制分为维管束鞘和叶肉细胞增加光合效率。与C-3叶片相比，C-4植物的碳浓缩机制允许在较低的气孔导度下进行光合作用，因此，蒸腾作用减少。在这里，我们的特点转录组保卫细胞在C-3 Tareneya hassleriana和C-4 Gynandropsis gynandra属于Cleomaceae。虽然约60%的基因本体论术语先前与保卫细胞从C-3模式拟南芥（拟南芥）是保守的，有少得多的重叠模式之间的个别基因表达。大多数离子和CO2信号模块出现在保卫细胞从C-3和C-4物种的转录水平不变，但与已知影响气孔行为的碳相关途径的转录本的主要变化进行了检测。与C-3叶片相比，C-4叶片保卫细胞中与光合作用相关的基因表达量更高。此外，我们检测到两个主要模式的细胞特异性C-4基因表达的C-4叶内。在第一，基因先前与优先表达的束鞘表现出不断降低的表达从束鞘叶肉保卫细胞。在第二，表达是最大的叶肉相比，保卫细胞和维管束鞘。这些数据表明，至少有两个基因调控网络的作用，以协调基因表达的维管束鞘，叶肉，和保卫细胞中的C-4叶。
C-4 photosynthesis represents an excellent example of convergent evolution that results in the optimization of both carbon and water usage by plants. In C-4 plants, a carbon-concentrating mechanism divided between bundle sheath and mesophyll cells increases photosynthetic efficiency. Compared with C-3 leaves, the carbon-concentrating mechanism of C-4 plants allows photosynthetic operation at lower stomatal conductance, and as a consequence, transpiration is reduced. Here, we characterize transcriptomes from guard cells in C-3 Tareneya hassleriana and C-4 Gynandropsis gynandra belonging to the Cleomaceae. While approximately 60% of Gene Ontology terms previously associated with guard cells from the C-3 model Arabidopsis (Arabidopsis thaliana) are conserved, there is much less overlap between patterns of individual gene expression. Most ion and CO2 signaling modules appear unchanged at the transcript level in guard cells from C-3 and C-4 species, but major variations in transcripts associated with carbon-related pathways known to influence stomatal behavior were detected. Genes associated with C-4 photosynthesis were more highly expressed in guard cells of C-4 compared with C-3 leaves. Furthermore, we detected two major patterns of cell-specific C-4 gene expression within the C-4 leaf. In the first, genes previously associated with preferential expression in the bundle sheath showed continually decreasing expression from bundle sheath to mesophyll to guard cells. In the second, expression was maximal in the mesophyll compared with both guard cells and bundle sheath. These data imply that at least two gene regulatory networks act to coordinate gene expression across the bundle sheath, mesophyll, and guard cells in the C-4 leaf.