The rice FISH BONE gene encodes a tryptophan aminotransferase, which affects pleiotropic auxin-related processes
The rice FISH BONE gene encodes a tryptophan aminotransferase, which affects pleiotropic auxin-related processes
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DOI：
10.1111/tpj.12517
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发表时间：
2014-06-01
期刊：
影响因子：
7.2
通讯作者：
Itoh, Jun-Ichi
中科院分区：
文献类型：
--
作者：
Yoshikawa, Takanori;Ito, Momoyo;Itoh, Jun-Ichi
生长素是一种基本的植物激素，其在器官中的定位对植物的生长发育起着至关重要的作用。对许多生长素合成缺陷突变体的分析表明，由拟南芥(TAA)和丝兰(YUC)家族色氨酸转氨酶催化的吲哚-3-丙酮酸(IPA)途径是吲哚-3-乙酸(IAA)生物合成的主要途径。相比之下，人们对水稻生长素生物合成的分子机制知之甚少。在本研究中，我们鉴定了一个与生长素相关的水稻突变体--鱼骨(Fib)。FIB编码TAA基因的同源基因，FIB功能的丧失导致了多效性的异常表型，如小叶片具有大的叶片关节角，维管发育异常，小圆锥花序，器官识别异常，根发育缺陷，以及体内IAA水平的降低。此外，我们还发现，在fib突变体中，生长素敏感性和极性转运活性发生了变化。根据这些结果，我们认为FIB在水稻IAA生物合成中起着关键作用，生长素的生物合成、运输和敏感性是密切相关的。
Auxin is a fundamental plant hormone and its localization within organs plays pivotal roles in plant growth and development. Analysis of many Arabidopsis mutants that were defective in auxin biosynthesis revealed that the indole-3-pyruvic acid (IPA) pathway, catalyzed by the TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS (TAA) and YUCCA (YUC) families, is the major biosynthetic pathway of indole-3-acetic acid (IAA). In contrast, little information is known about the molecular mechanisms of auxin biosynthesis in rice. In this study, we identified a auxin-related rice mutant, fish bone (fib). FIB encodes an orthologue of TAA genes and loss of FIB function resulted in pleiotropic abnormal phenotypes, such as small leaves with large lamina joint angles, abnormal vascular development, small panicles, abnormal organ identity and defects in root development, together with a reduction in internal IAA levels. Moreover, we found that auxin sensitivity and polar transport activity were altered in the fib mutant. From these results, we suggest that FIB plays a pivotal role in IAA biosynthesis in rice and that auxin biosynthesis, transport and sensitivity are closely interrelated.