Differentiation of endosperm transfer cells of barley: a comprehensive analysis at the micro-scale.
Differentiation of endosperm transfer cells of barley: a comprehensive analysis at the micro-scale.
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DOI：
10.1111/j.1365-313x.2012.05018.x
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发表时间：
2012-08
期刊：
影响因子：
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通讯作者：
J. Thiel;D. Riewe;T. Rutten;M. Melzer;S. Friedel;Felix Bollenbeck;W. Weschke;H. Weber
中科院分区：
文献类型：
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作者：
J. Thiel;D. Riewe;T. Rutten;M. Melzer;S. Friedel;Felix Bollenbeck;W. Weschke;H. Weber
大麦胚乳细胞分化为与珠心突起相反的传递细胞(ETC)。为了全面分析ETC的分化，从激光显微切割的组织中获得了基于激光显微切割的转录本和代谢物图谱，并对细胞形态进行了分析。授粉后5~7d，在最外层的3个细胞层内出现了凸缘状的次生壁内长。基因表达分析表明，乙烯信号通路启动了ETC形态。伴随着与细胞形状控制和囊泡运输相关的基因活性，具有丰富的线粒体和内膜结构。基因表达分析表明，主要形成半纤维素、葡萄糖醛酸木聚糖和阿拉伯木聚糖，以及瞬间形成的盔状糖，以及脯氨酸和4-羟基脯氨酸的生物合成。磷脂、果胶和乙烯的生物合成可能需要甲基化循环的激活。涉及甾醇/鞘磷脂和雷莫林的膜微区可能参与ETC的发展。同化物转运体和微量营养素转运体的转录活性表明，ETCs是溶质进入胚乳的主要吸收器官。相应地，胚乳在内分泌细胞完全发育后生长最大。与氨基酸分解代谢、C：N平衡、碳水化合物氧化、线粒体活性和淀粉降解相关的基因表达上调，满足了细胞增殖和壁面合成所需的呼吸能量和碳水化合物的高需求。在授粉后10天，ETCs经历进一步的分化，可能是由脱落酸启动的，代谢被重新编程，如激活的储存和胁迫相关的过程所示。总体而言，这些数据提供了大麦ETC分化和发育的综合视图，并确定了候选基因和相关途径。
Barley endosperm cells differentiate into transfer cells (ETCs) opposite the nucellar projection. To comprehensively analyse ETC differentiation, laser microdissection-based transcript and metabolite profiles were obtained from laser microdissected tissues and cell morphology was analysed. Flange-like secondary-wall ingrowths appeared between 5 and 7 days after pollination within the three outermost cell layers. Gene expression analysis indicated that ethylene-signalling pathways initiate ETC morphology. This is accompanied by gene activity related to cell shape control and vesicle transport, with abundant mitochondria and endomembrane structures. Gene expression analyses indicate predominant formation of hemicelluloses, glucuronoxylans and arabinoxylans, and transient formation of callose, together with proline and 4-hydroxyproline biosynthesis. Activation of the methylation cycle is probably required for biosynthesis of phospholipids, pectins and ethylene. Membrane microdomains involving sterols/sphingolipids and remorins are potentially involved in ETC development. The transcriptional activity of assimilate and micronutrient transporters suggests ETCs as the main uptake organs of solutes into the endosperm. Accordingly, the endosperm grows maximally after ETCs are fully developed. Up-regulated gene expression related to amino acid catabolism, C:N balances, carbohydrate oxidation, mitochondrial activity and starch degradation meets high demands for respiratory energy and carbohydrates, required for cell proliferation and wall synthesis. At 10 days after pollination, ETCs undergo further differentiation, potentially initiated by abscisic acid, and metabolism is reprogrammed as shown by activated storage and stress-related processes. Overall, the data provide a comprehensive view of barley ETC differentiation and development, and identify candidate genes and associated pathways.