Strigolactone Positively Controls Crown Root Elongation in Rice
Strigolactone Positively Controls Crown Root Elongation in Rice
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DOI：
10.1007/s00344-011-9228-6
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发表时间：
2012-06-01
影响因子：
4.8
通讯作者：
Kyozuka, Junko
中科院分区：
文献类型：
--
作者：
Arite, Tomotsugu;Kameoka, Hiromu;Kyozuka, Junko
最近发现独脚金内酯是抑制枝条分枝的植物激素。独脚金内酯缺陷或不敏感突变体中的多效性缺陷表明独脚金内酯控制植物生长和发育的各个方面。然而，我们对植物中独脚金内酯的激素功能的了解非常有限。在这项研究中，我们证明独脚金内酯缺陷或不敏感的水稻矮化突变体表现出短冠根表型。 GR24（一种合成的独脚金内酯类似物）的外源应用可以补充独脚金内酯缺陷突变体中的冠根缺陷，但不能补充独脚金内酯不敏感突变体中的冠根缺陷。这些观察结果表明独脚金内酯积极调节冠根的长度。组织学观察表明，矮化突变体的分生组织区比野生型短，这表明独脚金内酯可能通过控制细胞分裂对根发挥作用。我们还表明，野生型的冠根在磷酸盐饥饿下变得更长，但矮化突变体则不然。
Strigolactones are recently identified plant hormones that inhibit shoot branching. Pleiotropic defects in strigolactone-deficient or -insensitive mutants indicate that strigolactones control various aspects of plant growth and development. However, our understanding of the hormonal function of strigolactones in plants is very limited. In this study we demonstrate that rice dwarf mutants that are strigolactone-deficient or -insensitive exhibit a short crown root phenotype. Exogenous application of GR24, a synthetic strigolactone analog, complemented the crown root defect in strigolactone-deficient mutants but not in strigolactone-insensitive mutants. These observations imply that strigolactones positively regulate the length of crown roots. Histological observations revealed that the meristematic zone is shorter in dwarf mutants than in wild type, suggesting that strigolactones may exert their effect on roots via the control of cell division. We also show that crown roots of wild type, but not dwarf mutants, become longer under phosphate starvation.