Fructose sensitivity is suppressed in Arabidopsis by the transcription factor ANAC089 lacking the membrane-bound domain
Fructose sensitivity is suppressed in Arabidopsis by the transcription factor ANAC089 lacking the membrane-bound domain
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拟南芥中缺乏膜结合结构域的转录因子 ANAC089 抑制果糖敏感性
DOI：
10.1073/pnas.1018665108
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发表时间：
2011-02-22
影响因子：
11.1
通讯作者：
Teng, Sheng
中科院分区：
文献类型：
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作者：
Li, Ping;Wind, Julia J.;Teng, Sheng
在生物体中，糖不仅提供能量和碳骨架，而且还充当进化上保守的信号分子。植物中三种主要的可溶性糖是蔗糖、葡萄糖和果糖。关于植物葡萄糖和蔗糖信号传导的信息是可用的，但是迄今为止没有报道果糖特异性信号传导途径。本研究利用幼苗发育过程中的糖阻遏效应，对兰茨贝格/佛得角群岛重组自交系群体的果糖敏感性进行了研究，并定位了8个果糖敏感数量性状位点（FSQ 1 -8）。其中，FSQ 6通过分析Cvi基因组片段在Ler背景下渗入的近等基因系，被证实是果糖特异性QTL。这些结果表明在拟南芥中存在果糖特异性信号通路。进一步的分析表明，FSQ 6相关的果糖信号通路的功能独立于己糖激酶1（HXK 1）葡萄糖传感器。值得注意的是，果糖特异性FSQ 6下游信号转导与脱落酸（阿坝）和乙烯信号转导途径相互作用，类似于HXK 1依赖性葡萄糖信号转导。FSQ 6的Cvi等位基因充当果糖信号传导的抑制剂。利用图位克隆方法对FSQ 6基因进行了鉴定，结果表明FSQ 6基因编码拟南芥NAC（矮牵牛No apical meristem and Arabidopsis transcription activation factor 1，2 and Cup-shaped cotyledon 2）domain containing protein 89（ANAC 089）转录因子基因。FSQ 6/ANAC 089的Cvi等位基因是由该基因第三个外显子过早停止引起的功能获得性等位基因。截短的Cvi FSQ 6/ANAC 089蛋白缺乏存在于来自其他拟南芥属种质的ANAC 089蛋白中的膜缔合结构域。因此，Cvi FSQ 6/ANAC 089作为核中的转录因子具有组成型活性。
In living organisms sugars not only provide energy and carbon skeletons but also act as evolutionarily conserved signaling molecules. The three major soluble sugars in plants are sucrose, glucose, and fructose. Information on plant glucose and sucrose signaling is available, but to date no fructose-specific signaling pathway has been reported. In this study, sugar repression of seedling development was used to study fructose sensitivity in the Landsberg erecta (Ler)/Cape Verde Islands (Cvi) recombinant inbred line population, and eight fructose-sensing quantitative trait loci (QTLs) (FSQ1–8) were mapped. Among them, FSQ6 was confirmed to be a fructose-specific QTL by analyzing near-isogenic lines in which Cvi genomic fragments were introgressed in the Ler background. These results indicate the existence of a fructose-specific signaling pathway in Arabidopsis. Further analysis demonstrated that the FSQ6-associated fructose-signaling pathway functions independently of the hexokinase1 (HXK1) glucose sensor. Remarkably, fructose-specific FSQ6 downstream signaling interacts with abscisic acid (ABA)- and ethylene-signaling pathways, similar to HXK1-dependent glucose signaling. The Cvi allele of FSQ6 acts as a suppressor of fructose signaling. The FSQ6 gene was identified using map-based cloning approach, and FSQ6 was shown to encode the transcription factor gene Arabidopsis NAC (petunia No apical meristem and Arabidopsis transcription activation factor 1, 2 and Cup-shaped cotyledon 2) domain containing protein 89 (ANAC089). The Cvi allele of FSQ6/ANAC089 is a gain-of-function allele caused by a premature stop in the third exon of the gene. The truncated Cvi FSQ6/ANAC089 protein lacks a membrane association domain that is present in ANAC089 proteins from other Arabidopsis accessions. As a result, Cvi FSQ6/ANAC089 is constitutively active as a transcription factor in the nucleus.