Transcriptional and Metabolic Analysis of Senescence Induced by Preventing Pollination in Maize
Transcriptional and Metabolic Analysis of Senescence Induced by Preventing Pollination in Maize
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DOI：
10.1104/pp.112.199224
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发表时间：
2012-08-01
期刊：
影响因子：
7.4
通讯作者：
Kaeppler, Shawn M.
中科院分区：
文献类型：
--
作者：
Sekhon, Rajandeep S.;Childs, Kevin L.;Kaeppler, Shawn M.
研究了玉米B73基因型（Zea mays）在不授粉诱导衰老过程中转录和代谢的变化。早在花后12 d，游离葡萄糖和淀粉的积累以及叶绿素的损失就开始显现，而转录和表型的整体变化仅在花后24 d才出现。节间仅在30daa时表现出主要的转录组变化。将表达数据叠加到代谢途径上揭示了许多新途径的参与，包括那些参与细胞壁生物合成的途径。为了研究诱导衰老和自然衰老之间的重叠，我们将玉米诱导衰老的转录数据与报道的自然衰老和糖诱导衰老的拟南芥（Arabidopsis thaliana）进行比较。拟南芥与自然衰老的显著相似之处在于衰老相关基因（SAGs）、乙烯和茉莉酸生物合成基因、APETALA2、乙烯响应元件结合蛋白上调，而没有顶端分生组织转录因子。然而，与自然衰老的不同之处在于，sag的一个子集、细胞分裂素、脱落酸和水杨酸生物合成基因的表达没有改变。糖诱导的拟南芥衰老过程中上调的关键基因，包括半胱氨酸蛋白酶（SAG12）和3个类黄酮生物合成基因（花青素色素生产1 （PAP1）、PAP2和亮色花青素双加氧酶）也被诱导，表明授粉预防和糖诱导的衰老具有相似性。共表达分析揭示了涉及已知衰老相关基因和新的候选基因的网络；其中82个基因在叶片和节间网络之间共享，这突出了这些组织在诱导衰老方面的相似性。这项研究的见解将对玉米和其他禾本科植物的衰老系统生物学有价值。
Transcriptional and metabolic changes were evaluated during senescence induced by preventing pollination in the B73 genotype of maize (Zea mays). Accumulation of free glucose and starch and loss of chlorophyll in leaf was manifested early at 12 d after anthesis (DAA), while global transcriptional and phenotypic changes were evident only at 24 DAA. Internodes exhibited major transcriptomic changes only at 30 DAA. Overlaying expression data onto metabolic pathways revealed involvement of many novel pathways, including those involved in cell wall biosynthesis. To investigate the overlap between induced and natural senescence, transcriptional data from induced senescence in maize was compared with that reported for Arabidopsis (Arabidopsis thaliana) undergoing natural and sugar-induced senescence. Notable similarities with natural senescence in Arabidopsis included up-regulation of senescence-associated genes (SAGs), ethylene and jasmonic acid biosynthetic genes, APETALA2, ethylene-responsive element binding protein, and no apical meristem transcription factors. However, differences from natural senescence were highlighted by unaltered expression of a subset of the SAGs, and cytokinin, abscisic acid, and salicylic acid biosynthesis genes. Key genes up-regulated during sugar-induced senescence in Arabidopsis, including a cysteine protease (SAG12) and three flavonoid biosynthesis genes (PRODUCTION OF ANTHOCYANIN PIGMENT1 (PAP1), PAP2, and LEUCOANTHOCYANIDIN DIOXYGENASE), were also induced, suggesting similarities in senescence induced by pollination prevention and sugar application. Coexpression analysis revealed networks involving known senescence-related genes and novel candidates; 82 of these were shared between leaf and internode networks, highlighting similarities in induced senescence in these tissues. Insights from this study will be valuable in systems biology of senescence in maize and other grasses.