Transcriptome analysis of senescence in the flag leaf of wheat (Triticum aestivum L.)
Transcriptome analysis of senescence in the flag leaf of wheat (Triticum aestivum L.)
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DOI：
10.1111/j.1467-7652.2006.00232.x
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发表时间：
2007-01-01
影响因子：
13.8
通讯作者：
Holm, Preben Bach
中科院分区：
文献类型：
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作者：
Gregersen, Per L.;Holm, Preben Bach
使用基于 9K 小麦单基因组的内部制造的 cDNA 微阵列，研究了从穗出现到收获的叶子样品 50% 黄化的一段时间过程中小麦旗叶的衰老过程。对排名前 1000 个差异表达探针进行聚类分析，从中我们选择了 140 个带有信息注释的上调基因。该基因列表与之前观察到的与其他物种衰老相关的基因之间存在相当大的重叠，涵盖了涉及大分子降解和营养物质再利用的几个功能类别，特别是通过羧酸和氨基酸代谢的氮。实时聚合酶链式反应实验证实了这种代谢中许多基因的上调。数据表明胞质/过氧化物酶体途径在碳水化合物、脂肪酸和蛋白质降解整合中的作用，导致氮的再动员。上调基因的说明性实例包括细胞质乌头酸水合酶和过氧化物酶体柠檬酸合酶。这些数据支持线粒体通过替代氧化酶的上调对氧化细胞损伤发挥保护作用，并且可能还涉及上调的琥珀酸脱氢酶。还鉴定出了许多上调的调控基因，特别是 NAC 结构域和 WRKY 转录因子。这些因素此前已被确定与其他物种的衰老有关。这些数据支持这样的观点，即单子叶植物和双子叶植物物种都存在通用的衰老程序。然而，也可以看出显着的差异。因此，我们发现苯并恶嗪类化合物（一组禾本科特异性次级代谢物）的生物合成途径的转录上调。
The senescence process in wheat flag leaves was investigated over a time course from ear emergence until 50% yellowing of harvested leaf samples using an in-house fabricated cDNA microarray based on a 9K wheat unigene set. The top 1000 ranked differentially expressed probes were subjected to a cluster analysis and, from these, we selected 140 up-regulated genes with informative annotations. There was a considerable overlap between this list of genes and genes previously observed to be associated with senescence in other species, covering several functional categories involved in the degradation of macromolecules and nutrient remobilization, notably of nitrogen via the metabolism of carboxylic and amino acids. The up-regulation of a number of genes in this metabolism was confirmed by real-time polymerase chain reaction experiments. The data suggest a role for cytosolic/peroxisomal routes in the integration of the degradation of carbohydrates, fatty acids and proteins, leading to the remobilization of nitrogen. Illustrative examples of up-regulated genes comprise cytoplasmic aconitate hydratase and peroxisomal citrate synthase. The data support a protective role of the mitochondria towards oxidative cell damage via the up-regulation of the alternative oxidase, and possibly also involving the up-regulated succinate dehydrogenase. A number of up-regulated regulatory genes were also identified, notably NAC-domain and WRKY transcription factors. These factors have previously been identified as being associated with senescence in other species. The data support the notion that a generic senescence programme exists across monocot and dicot plant species. However, notable differences can also be recognized. We thus found transcriptional up-regulation of the biosynthetic pathway for benzoxazinoids, a group of graminaceous-specific secondary metabolites.