A Novel 2-Oxoacid-Dependent Dioxygenase Involved in the Formation of the Goiterogenic 2-Hydroxybut-3-enyl Glucosinolate and Generalist Insect Resistance in Arabidopsis
A Novel 2-Oxoacid-Dependent Dioxygenase Involved in the Formation of the Goiterogenic 2-Hydroxybut-3-enyl Glucosinolate and Generalist Insect Resistance in Arabidopsis
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DOI：
10.1104/pp.108.129981
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发表时间：
2008-12-01
期刊：
影响因子：
7.4
通讯作者：
Kliebenstein, Daniel J.
中科院分区：
文献类型：
--
作者：
Hansen, Bjarne G.;Kerwin, Rachel E.;Kliebenstein, Daniel J.
硫代葡萄糖苷是几乎仅存在于植物目中的次级代谢产物。它们由多种氨基酸合成，并且可以具有控制生物功能的许多侧链修饰。我们研究了2-羟基丁-3-烯基硫代葡萄糖苷的生物合成，其生物活性包括对秀丽隐杆线虫的毒性，抑制种子萌发，诱导哺乳动物甲状腺肿疾病，以及在芸苔属蔬菜作物中产生苦味。拟南芥（Arabidopsis thaliana）种质含有三种不同模式的2-羟基丁-3-烯基硫代葡萄糖苷积累（存在于叶和种子中，仅存在于种子中，或不存在），对应于单个基因座GSL-OH处的三个不同等位基因。GSL-OH基因座的精细标度作图鉴定了由At 2g 25450编码的2-含氧酸依赖性双加氧酶，其是从前体3-丁烯基芥子油苷前体形成2 R-和2S-2-羟基丁-3-烯基芥子油苷所需的。At 2g 25450中自然发生的无效突变和T-DNA插入突变表现出完全不存在2-羟基丁-3-烯基芥子油苷积累。对通性鳞翅目粉纹夜蛾的食草性分析表明，2-羟基丁-3-烯基硫代葡萄糖酸的产生可以提高抗性。这些结果表明，At 2g 25450是必要的丁-3-烯基芥子油苷的羟基化为2-羟基丁-3-烯基芥子油苷在植物和这种代谢物增加抗性通性植食性。
Glucosinolates are secondary metabolites found almost exclusively in the order Brassicales. They are synthesized from a variety of amino acids and can have numerous side chain modifications that control biological function. We investigated the biosynthesis of 2-hydroxybut-3-enyl glucosinolate, which has biological activities including toxicity to Caenorhabditis elegans, inhibition of seed germination, induction of goiter disease in mammals, and production of bitter flavors in Brassica vegetable crops. Arabidopsis ( Arabidopsis thaliana) accessions contain three different patterns of 2-hydroxybut-3-enyl glucosinolate accumulation ( present in leaves and seeds, seeds only, or absent) corresponding to three different alleles at a single locus, GSL-OH. Fine-scale mapping of the GSL-OH locus identified a 2-oxoacid-dependent dioxygenase encoded by At2g25450 required for the formation of both 2R- and 2S-2-hydroxybut-3-enyl glucosinolate from the precursor 3-butenyl glucosinolate precursor. Naturally occurring null mutations and T-DNA insertional mutations in At2g25450 exhibit a complete absence of 2-hydroxybut-3-enyl glucosinolate accumulation. Analysis of herbivory by the generalist lepidopteran Trichoplusia ni showed that production of 2-hydroxybut-3-enyl glucosinolate provides increased resistance. These results show that At2g25450 is necessary for the hydroxylation of but-3-enyl glucosinolate to 2-hydroxybut-3-enyl glucosinolate in planta and that this metabolite increases resistance to generalist herbivory.