SIS8, a putative mitogen-activated protein kinase kinase kinase, regulates sugar-resistant seedling development in Arabidopsis
SIS8, a putative mitogen-activated protein kinase kinase kinase, regulates sugar-resistant seedling development in Arabidopsis
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DOI：
10.1111/tpj.12404
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发表时间：
2014-02-01
期刊：
影响因子：
7.2
通讯作者：
Gibson, Susan I.
中科院分区：
文献类型：
--
作者：
Huang, Yadong;Li, Chun Yao;Gibson, Susan I.
糖信号通路在真核生物中进化上是保守的，被认为有助于调节植物的生长、发育和对环境提示的反应。正向遗传筛选已经发现了糖信号或反应突变体。在这里，我们报告了拟南芥糖不敏感8(Sis8)突变体的鉴定和特性，该突变体表现出抗糖幼苗发育表型。与许多其他糖不敏感突变体不同，siS8突变体对脱落酸和多效唑(赤霉素生物合成抑制剂)对种子萌发的抑制作用表现出野生型反应。SIS8基因的定位克隆表明，它编码一个可能的丝裂原激活蛋白激酶(MAPKKK；at1g73660)。SIS8mRNA在拟南芥各器官中普遍表达。根据酵母双杂交筛选和植物双分子荧光互补技术，UDP-葡萄糖转移酶UGT72E1(At3g50740)被鉴定为SIS8的相互作用伙伴。SIS8-黄色荧光蛋白(YFP)和UGT72E1-YFP融合蛋白在烟草细胞中瞬时表达时均定位于细胞核。AT3g50740中的T-DNA插入导致了糖不敏感的表型。这些结果表明，SIS8，一个可能的MAPKKK，是拟南芥中糖反应的调节因子，并与细胞核中的UDP-葡萄糖转移酶相互作用。
Sugar signaling pathways have been evolutionarily conserved among eukaryotes and are postulated to help regulate plant growth, development and responses to environmental cues. Forward genetic screens have identified sugar signaling or response mutants. Here we report the identification and characterization of Arabidopsis thaliana sugar insensitive8 (sis8) mutants, which display a sugar-resistant seedling development phenotype. Unlike many other sugar insensitive mutants, sis8 mutants exhibit wild-type responses to the inhibitory effects of abscisic acid and paclobutrazol (an inhibitor of gibberellin biosynthesis) on seed germination. Positional cloning of the SIS8 gene revealed that it encodes a putative mitogen-activated protein kinase kinase kinase (MAPKKK; At1g73660). SIS8mRNA is expressed ubiquitously among Arabidopsis organs. A UDP-glucosyltransferase, UGT72E1 (At3g50740), was identified as an interacting partner of SIS8 based on a yeast two-hybrid screen and in planta bimolecular fluorescence complementation. Both SIS8-yellow fluorescent protein (YFP) and UGT72E1-YFP fusion proteins localize to the nucleus when transiently expressed in tobacco leaf cells. T-DNA insertions in At3g50740 cause a sugar-insensitive phenotype. These results indicate that SIS8, a putative MAPKKK, is a regulator of sugar response in Arabidopsis and interacts with a UDP-glucosyltransferase in the nucleus.