Photosynthate Regulation of the Root System Architecture Mediated by the Heterotrimeric G Protein Complex in Arabidopsis.
Photosynthate Regulation of the Root System Architecture Mediated by the Heterotrimeric G Protein Complex in Arabidopsis.
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DOI：
10.3389/fpls.2016.01255
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发表时间：
2016
影响因子：
5.6
通讯作者：
Jones AM
中科院分区：
文献类型：
--
作者：
Mudgil Y;Karve A;Teixeira PJ;Jiang K;Tunc-Ozdemir M;Jones AM
同化物分配到根系是一个理想的发育性状，以控制，但很少有人知道的信号转导途径的分配。编码异源三聚体G蛋白复合物的Gβ亚基的基因中的无效突变（多种信号传导途径的联系）赋予根中改变的糖分配。野生型和agb 1 -2突变体幼苗的根中固定碳迅速到达，而agb 1的根中以葡萄糖、果糖和蔗糖形式存在的固定碳更多，表现为侧根密度更高。经葡萄糖处理后，转录组分析证实agb 1 -2突变体在根尖有异常基因表达。此外，PIN 2膜定位在agb 1 -2突变体中改变。异源三聚体G蛋白复合物整合了光合作用衍生的糖信号传导，并结合了基于膜和转录的机制。这些信号传导机制的时间常数与向根递送光合产物的时间常数在相同的范围内，这提高了根细胞能够在真实的时间内利用碳固定的变化来调整生长行为的可能性。
Assimilate partitioning to the root system is a desirable developmental trait to control but little is known of the signaling pathway underlying partitioning. A null mutation in the gene encoding the Gβ subunit of the heterotrimeric G protein complex, a nexus for a variety of signaling pathways, confers altered sugar partitioning in roots. While fixed carbon rapidly reached the roots of wild type and agb1-2 mutant seedlings, agb1 roots had more of this fixed carbon in the form of glucose, fructose, and sucrose which manifested as a higher lateral root density. Upon glucose treatment, the agb1-2 mutant had abnormal gene expression in the root tip validated by transcriptome analysis. In addition, PIN2 membrane localization was altered in the agb1-2 mutant. The heterotrimeric G protein complex integrates photosynthesis-derived sugar signaling incorporating both membrane-and transcriptional-based mechanisms. The time constants for these signaling mechanisms are in the same range as photosynthate delivery to the root, raising the possibility that root cells are able to use changes in carbon fixation in real time to adjust growth behavior.