Tryptophan deficiency affects organ growth by retarding cell expansion in Arabidopsis
Tryptophan deficiency affects organ growth by retarding cell expansion in Arabidopsis
复制标题
色氨酸缺乏通过阻碍拟南芥细胞的扩张来影响器官生长
DOI：
10.1111/j.1365-313x.2008.03706.x
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发表时间：
2009-02-01
期刊：
影响因子：
7.2
通讯作者：
Hu, Yuxin
中科院分区：
文献类型：
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作者：
Jing, Yanjun;Cui, Dayong;Hu, Yuxin
色氨酸（Trp）是一种必需氨基酸，不仅是蛋白质合成所必需的，也是许多植物代谢产物（包括激素生长素）产生所必需的。Trp生物合成的突变导致植物器官的各种发育缺陷，但Trp如何影响器官生长和发育仍不清楚。在这里，我们确定了一个拟南芥突变体，小器官1（smo 1/trp 2 -301），表现出减少其气生器官的大小作为一个结果的生长迟缓的细胞扩张，而不是由生长迟缓的细胞增殖。smo 1/trp 2 -301在TSB 1中含有一个损伤，该损伤编码主要表达的Trp合酶β亚基，并且与trp 2突变体是等位基因。进一步的分析表明，在trp 2叶细胞中，核内复制受损，叶绿体发育延迟。此外，细胞扩张和叶片生长可以恢复trp 2的外源应用的色氨酸，但不是由生长素，一般的蛋白质合成没有明显影响trp 2突变体。我们的研究结果表明，缺乏色氨酸或其衍生物是植物器官发生过程中细胞扩增的生长限制因素。
Tryptophan (Trp) is an essential amino acid required not only for protein synthesis but also for the production of many plant metabolites, including the hormone auxin. Mutations that disrupt Trp biosynthesis result in various developmental defects in plant organs, but how Trp affects organ growth and development remains unclear. Here, we identify an Arabidopsis mutant, small organ1 (smo1/trp2-301), which exhibits a reduction in the size of its aerial organs as a result of the retardation of growth by cell expansion, rather than by the retardation of growth by cell proliferation. smo1/trp2-301 contains a lesion in TSB1 that encodes a predominantly expressed Trp synthase beta-subunit, and is allelic with trp2 mutants. Further analyses show that in trp2 leaf cells, the nuclear endoreduplication is impaired and chloroplast development is delayed. Furthermore, cell expansion and leaf growth in trp2 can be restored by the exogenous application of Trp, but not by auxin, and the general protein synthesis is not apparently affected in trp2 mutants. Our findings suggest that the deficiency in Trp or its derivatives is a growth-limiting factor for cell expansion during plant organogenesis.