The rice HIGH-TILLERING DWARF1 encoding an ortholog of Arabidopsis MAX3 is required for negative regulation of the outgrowth of axillary buds.
The rice HIGH-TILLERING DWARF1 encoding an ortholog of Arabidopsis MAX3 is required for negative regulation of the outgrowth of axillary buds.
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DOI：
10.1111/j.1365-313x.2006.02916.x
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发表时间：
2006-12
期刊：
影响因子：
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通讯作者：
Junhuang Zou;Shuying Zhang;Weiping Zhang;Gang Li;Zongxiang Chen;W. Zhai;Xianfeng Zhao;Xuebiao Pan-Xuebia
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文献类型：
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作者：
Junhuang Zou;Shuying Zhang;Weiping Zhang;Gang Li;Zongxiang Chen;W. Zhai;Xianfeng Zhao;Xuebiao Pan-Xuebia
水稻分蘖是影响粮食生产的重要农艺性状。高TILLERING DWARF1(HTD1)基因编码拟南芥MAX3的同源基因。对htd1的互补分析证实，htd1的缺陷导致了htd1突变体的高分蘖和矮化两种表型。Pro(35S)：HTD1的引入挽救了拟南芥MAX3突变体的表型，表明HTD1是一种类胡萝卜素裂解双加氧酶，在合成类胡萝卜素衍生的信号分子方面与MAX3具有相同的功能。HTD1基因在地上部和根组织中均有表达。通过检测Pro(HTD1)：GUS的表达，我们发现HTD1基因主要在整个植物的维管束组织中表达。生长素对htd1基因表达的诱导表明，生长素可能部分通过上调htd1基因转录来调节水稻分蘖。腋芽摘除后矮秆表型的恢复表明，htd1突变体的矮化可能是分蘖过多的结果。此外，htd1和d3突变体中htd1、d3和OsCCD8a的表达表明，水稻类胡萝卜素信号的合成和感知可能存在反馈机制。拟南芥中MAX基因的特征及其在豌豆、矮牵牛和水稻中的同源基因鉴定表明，在单子叶和双子叶植物中都存在着一种保守的分枝调控机制。
Rice tillering is an important agronomic trait for grain production. The HIGH-TILLERING DWARF1 (HTD1) gene encodes an ortholog of Arabidopsis MAX3. Complementation analyses for HTD1 confirm that the defect in HTD1 is responsible for both high-tillering and dwarf phenotypes in the htd1 mutant. The rescue of the Arabidopsis max3 mutant phenotype by the introduction of Pro(35S):HTD1 indicates HTD1 is a carotenoid cleavage dioxygenase that has the same function as MAX3 in synthesis of a carotenoid-derived signal molecule. The HTD1 gene is expressed in both shoot and root tissues. By evaluating Pro(HTD1):GUS expression, we found that the HTD1 gene is mainly expressed in vascular bundle tissues throughout the plant. Auxin induction of HTD1 expression suggests that auxin may regulate rice tillering partly through upregulation of HTD1 gene transcription. Restoration of dwarf phenotype after the removal of axillary buds indicates that the dwarfism of the htd1 mutant may be a consequence of excessive tiller production. In addition, the expression of HTD1, D3 and OsCCD8a in the htd1 and d3 mutants suggests a feedback mechanism may exist for the synthesis and perception of the carotenoid-derived signal in rice. Characterization of MAX genes in Arabidopsis, and identification of their orthologs in pea, petunia and rice indicates the existence of a conserved mechanism for shoot-branching regulation in both monocots and dicots.