d14, a Strigolactone-Insensitive Mutant of Rice, Shows an Accelerated Outgrowth of Tillers
d14, a Strigolactone-Insensitive Mutant of Rice, Shows an Accelerated Outgrowth of Tillers
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DOI：
10.1093/pcp/pcp091
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发表时间：
2009-08-01
影响因子：
4.9
通讯作者：
Kyozuka, Junko
中科院分区：
文献类型：
--
作者：
Arite, Tomotsugu;Umehara, Mikihisa;Kyozuka, Junko
最近对豌豆、拟南芥和水稻的高分枝突变体的研究表明，甾体内酯（一类萜类内酯）是一种新的激素类或其生物合成前体，可抑制茎枝分枝。在这里，我们提供了证据，表明DWARF14 （D14）可以抑制水稻分蘖，并且可能是独角戊内酯依赖分支抑制途径的新组成部分。d14突变体表现出增加的枝分枝和降低的株高，与之前所描述的孤孤内酯缺乏和不敏感突变体d10和d3相似。D10 -1 D14 -1双突变体在表型上与D10 -1和D14 -1单突变体难以区分，这与D10和D14在同一途径中起作用的观点一致。然而，与d10不同的是，d14的分支表型不能被外源的独角酯内酯拯救。此外，与野生型相比，d14突变体含有更高水平的2-epi-5-脱氧寡糖醇。定位克隆发现，D14编码一个/-fold水解酶超家族的蛋白，该家族的一些成员在植物激素的代谢或信号转导中起作用。我们认为D14在独角兽内酯合成的下游发挥作用，作为激素信号的组成部分或作为参与将独角兽内酯转化为生物活性形式的酶。
Recent studies using highly branched mutants of pea, Arabidopsis and rice have demonstrated that strigolactones, a group of terpenoid lactones, act as a new hormone class, or its biosynthetic precursors, in inhibiting shoot branching. Here, we provide evidence that DWARF14 (D14) inhibits rice tillering and may act as a new compo-nent of the strigolactone-dependent branching inhibition pathway. The d14 mutant exhibits increased shoot branch-ing with reduced plant height like the previously characterized strigolactone-deficient and -insensitive mutants d10 and d3, respectively. The d10-1 d14-1 double mutant is phenotypically indistinguishable from the d10-1 and d14-1 single mutants, consistent with the idea that D10 and D14 function in the same pathway. However, unlike with d10, the d14 branching phenotype could not be rescued by exogenous strigolactones. In addition, the d14 mutant contained a higher level of 2-epi-5-deoxystrigol than the wild type. Positional cloning revealed that D14 encodes a protein of the /-fold hydrolase superfamily, some members of which play a role in metabolism or signaling of plant hormones. We propose that D14 functions downstream of strigolactone synthesis, as a component of hormone signaling or as an enzyme that participates in the conversion of strigolactones to the bioactive form.