Molecular mechanism of crown root initiation and the different mechanisms between crown root and radicle in rice
Molecular mechanism of crown root initiation and the different mechanisms between crown root and radicle in rice
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DOI：
10.4161/psb.6.9.16787
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发表时间：
2011-01-01
影响因子：
2.9
通讯作者：
Inukai, Yoshiaki
中科院分区：
文献类型：
--
作者：
Kitomi, Yuka;Kitano, Hidemi;Inukai, Yoshiaki
单子叶植物产生大量不定(冠)根。植物激素生长素对冠根的形成有促进作用，而细胞分裂素对冠根的形成有抑制作用。我们已经证明，生长素诱导的冠状根5(CRL5)通过细胞分裂素信号的负调控因子OsRR1的诱导来调节水稻冠根的起始。CRL5过表达的愈伤组织形成了不定根，而CRL5过表达的植株不能诱导异位根，这表明CRL5可能只在去分化的细胞中起作用。在cr15突变体中，尽管冠根起始存在缺陷，但仍能正常地产生胚根，而在无根突变体(Ral1)中，只产生冠根，而不产生胚根。一个cr15ral1双突变体表现为加性表型，表明水稻各根的形成受不同的遗传机制调控。
Monocot plants produce numerous adventitious (crown) roots. The plant hormone auxin has positive effects on crown root formation, while cytokinin suppresses it. We have demonstrated that auxin-induced CROWN ROOTLESS5 (CRL5) regulates crown root initiation in rice through the induction of OsRR1, a negative regulator of cytokinin signaling. CRL5 overexpressing calli formed adventitious roots, although CRL5 overexpressing plants did not induce ectopic roots, suggesting that CRL5, which promotes de novo root initiation, might function only in de-differentiated cells. A radicle initiated normally in a crl5 mutant, in spite of the defect in crown root initiation, whereas crown roots, but not a radicle, were produced in a radicleless1 (ral1) mutant. A crl5 ral1 double mutant displayed an additive phenotype, showing that the formation of each root is regulated by different genetic mechanisms in rice.