Overexpression of the Arabidopsis Gene UPRIGHT ROSETTE Reveals a Homeostatic Control for Indole-3-Acetic Acid
Overexpression of the Arabidopsis Gene UPRIGHT ROSETTE Reveals a Homeostatic Control for Indole-3-Acetic Acid
复制标题
拟南芥基因 UPRIGHT ROSETTE 的过度表达揭示了吲哚-3-乙酸的稳态控制
DOI：
10.1104/pp.110.154021
复制
发表时间：
2010-07-01
期刊：
影响因子：
7.4
通讯作者：
Huang, Hai
中科院分区：
文献类型：
--
作者：
Sun, Yue;Yang, Yang;Huang, Hai
生长素是一种植物激素，对植物生长发育的许多方面都至关重要。植物产生的生长素主要是吲哚-3-乙酸（IAA）。IAA以游离和共轭形式存在，分别对应于生物活性激素和储存激素。游离IAA水平对各种生理活动至关重要，它是通过一个复杂的环境和发育响应途径网络维持的，包括IAA的生物合成、运输、降解、偶联和偶联水解。在共轭IAA形式中，酯型和酰胺型共轭物是最常见的。在这里，我们鉴定了一个新的基因，直立玫瑰（URO），其过表达改变IAA在拟南芥（拟南芥）的稳态。我们之前发现了一个半显性突变体，uro，它具有多种生长素相关表型。我们在这里发现，与野生型植物相比，uro植物含有更多的游离和酯偶联IAA，而较少的氨基偶联IAA。携带pDR5: β -葡萄糖醛酸苷酶（GUS）构建体的植株子叶和茎部GUS染色较强，子叶在无生长素的培养基上能够生根，进一步证实该突变体含有较高水平的游离IAA。URO基因编码C2H2锌指蛋白，属于植物特异性基因家族。在转基因p35S:URO/pGH3:GUS/Physcomitrella patens和pNOS:URO/pGH3:GUS/P中，可能反映游离IAA水平的GUS活性显著增加，因此对URO过表达的反应在植物间具有进化保守性。金属盘植物。
Auxins are phytohormones that are essential for many aspects of plant growth and development. The main auxin produced by plants is indole-3-acetic acid (IAA). IAA exists in free and conjugated forms, corresponding to the bioactive and stored hormones, respectively. Free IAA levels, which are crucial for various physiological activities, are maintained through a complex network of environmentally and developmentally responsive pathways including IAA biosynthesis, transport, degradation, conjugation, and conjugate hydrolysis. Among conjugated IAA forms, ester- and amide-type conjugates are the most common. Here we identify a new gene, UPRIGHT ROSETTE (URO), the overexpression of which alters IAA homeostasis in Arabidopsis (Arabidopsis thaliana). We previously identified a semidominant mutant, uro, which had multiple auxin-related phenotypes. We show here that compared to wild-type plants, the uro plants contain increased levels of free and ester-conjugated IAA, and decreased levels of amino-conjugated IAA. uro plants carrying the pDR5:beta-glucuronidase (GUS) construct have strong GUS staining in cotyledons and stem, and their cotyledons are able to generate roots on auxin-free medium, further confirming that this mutant contains higher levels of free IAA. The URO gene encodes a C2H2 zinc-finger protein that belongs to a plant-specific gene family. The response to URO overexpression is evolutionarily conserved among plants, as GUS activity that may reflect free IAA levels was increased markedly in transgenic p35S:URO/pGH3:GUS/Physcomitrella patens and pNOS:URO/pGH3:GUS/P. patens plants.