Non-dormant Axillary Bud 1 regulates axillary bud outgrowth in sorghum
Non-dormant Axillary Bud 1 regulates axillary bud outgrowth in sorghum
复制标题
非休眠腋芽1调节高粱腋芽生长
DOI：
10.1111/jipb.12665
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发表时间：
2018-10-01
影响因子：
11.4
通讯作者：
Cai, Hongwei
中科院分区：
文献类型：
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作者：
Chen, Jun;Zhang, Limin;Cai, Hongwei
分蘖有助于谷物产量和植物结构，因此是高粱（Sorghum bicolor）的重要农艺性状。在这里，我们确定和功能特点的非休眠腋芽1（NAB 1）基因的甲基磺酸乙酯诱变高粱人口的突变体。nabi突变体增加了分蘖，降低了植株高度。基于图位的克隆显示NAB 1编码类胡萝卜素裂解双加氧酶7（CCD 7），其与水稻（Oryza sativa）高分蘖DWARF 1/DWARF 17和拟南芥（Arabidopsis thaliana）多轴分枝3同源。NAB 1主要在腋生节和分蘖基部表达，NAB 1定位于叶绿体。nab 1突变导致基生腋芽的生长，去除这些非休眠的基生腋芽恢复野生型表型。nab 1植物的分蘖完全抑制外源应用的合成独脚金内酯类似物GR 24。此外，nab 1植物没有检测到独脚金内酯，并显示出更强的极性生长素运输比野生型植物。最后，RNA-seq显示，参与多个过程的基因（包括生长素相关基因）的表达在nab 1中发生了显著改变。这些结果表明，NAB 1功能独脚金内酯的生物合成和调控的芽分枝通过与生长素运输的相互作用。
Tillering contributes to grain yield and plant architecture and therefore is an agronomically important trait in sorghum (Sorghum bicolor). Here, we identified and functionally characterized a mutant of the Nondormant Axillary Bud 1 (NAB1) gene from an ethyl methanesulfonate-mutagenized sorghum population. The nabi mutants have increased tillering and reduced plant height. Map-based cloning revealed that NAB1 encodes a carotenoid-cleavage dioxygenase 7 (CCD7) orthologous to rice (Oryza sativa) HIGH-TILLERING DWARF1/DWARF17 and Arabidopsis thaliana MORE AXILLARY BRANCHING 3. NAB1 is primarily expressed in axillary nodes and tiller bases and NAB1 localizes to chloroplasts. The nab1 mutation causes outgrowth of basal axillary buds; removing these non-dormant basal axillary buds restored the wild-type phenotype. The tillering of nab1 plants was completely suppressed by exogenous application of the synthetic strigolactone analog GR24. Moreover, the nab1 plants had no detectable strigolactones and displayed stronger polar auxin transport than wild-type plants. Finally, RNA-seq showed that the expression of genes involved in multiple processes, including auxin-related genes, was significantly altered in nab1. These results suggest that NAB1 functions in strigolactone biosynthesis and the regulation of shoot branching via an interaction with auxin transport.