Gibberellin Signaling: A Theme and Variations on DELLA Repression
Gibberellin Signaling: A Theme and Variations on DELLA Repression
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DOI：
10.1104/pp.112.200956
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发表时间：
2012-09-01
期刊：
影响因子：
7.4
通讯作者：
Steber, Camille M.
中科院分区：
文献类型：
--
作者：
Hauvermale, Amber L.;Ariizumi, Tohru;Steber, Camille M.
GA是一类四环二萜类植物激素，可刺激植物生长和发育转变。作为固着生物，植物依靠发育可塑性来应对环境挑战。植物激素调节对各种环境刺激的发育反应，如光、温度、湿度、动物喂养和疾病压力的变化。GA刺激种子萌发以响应光、温度和湿度的变化（Koornneef和货车der Veen，1980; Yamauchi等人，2004; Seo等人，2009年）。GA还通过响应于光或暗的细胞扩增和细胞分裂来刺激茎伸长和叶扩增（光形态发生和skotomorphogenesis; Ogawa等人，2003年; Zuadí等人，2008; Feng等人，2008; de Lucas等人，2008; Gallego-Bartolomé等人，2011年）。GA刺激从分生组织到芽生长、从幼叶到成叶发育以及从营养生长到开花的发育转变，并且还刺激花发育的各个方面（Telfer et al.，1997年; Yu等人，2004; Galinha等人，2009年）。对这些事件的适当调节对于植物物种的生存和成功的作物生产至关重要。GA通过解除DELLA（Asp-Glu-Leu-Leu-Ala）蛋白对这些事件的抑制来刺激植物生长和发育的许多方面。本文将回顾多种生化机制的调节和响应DELLA镇压。使用具有改变的GA生物合成或catalysts的植物的研究已经产生了关于GA在植物生长和发育中的不同作用的丰富知识（对于综述，参见Sun和Gubler，2004; Yamaguchi，2008）。双子叶植物和单子叶植物的GA生物合成酶突变体是GA敏感的，显示出通过GA应用而挽救的生长和发育缺陷。水稻（Oryza sativa）和大麦（Hordeum vulgare）的GA敏感突变体表现出矮化、不育和在种子萌发期间不能通过α-淀粉酶诱导调动储存储备（Zwar和钱德勒，1995;钱德勒和Robertson，1999; Sakamoto等人，2004年）。在拟南芥（Arabidopsis thaliana）突变体中观察到类似的表型，所述突变体影响在生物合成途径中稍后起作用的酶，GA 3-氧化酶（GA 3 ox）和GA 20 ox（Hedden和Phillips，2000; Plackett等人，2012年）。由于GA_（3 ox）和GA_（20 ox）属于多基因家族，因此单突变体是可育的半矮秆。在拟南芥和番茄（Solanum lycopersicum）中，影响早期GA生物合成酶如对映-柯巴基二磷酸合酶的突变体（Sun和Kamiya，1994）导致种子发芽失败，生长为暗绿色矮化，在短日照下不能过渡到开花，以及部分至完全不育（Koornneef和货车der Veen，1980; Karssen等人，1989; Wilson等人，1992年）。编码GA分解代谢酶GA 2 ox的基因的过表达增加GA周转，导致小麦中谷粒发芽和α-淀粉酶诱导减少（Triticum aestivum; Appleford等人，2007）和拟南芥种子发育和花粉管生长失败（Singh et al.，2002年）。GA信号通常通过响应环境或发育刺激的GA 20 ox、GA 3 ox和GA 2 ox表达的变化介导的激素积累的直接调节来控制。这是合乎逻辑的，因为激素是激素信号通路的第一步。通过红光或冷吸胀刺激拟南芥种子萌发和通过远红光抑制萌发分别与GA积累的增加和减少相关（综述参见Seo et al.，2009年）。远红光抑制种子生长
GAs are a family of tetracyclic diterpenoid plant hormones that stimulate plant growth and developmental transitions. As sessile organisms, plants rely on developmental plasticity to respond to environmental challenges. Plant hormones regulate developmental responses to diverse environmental stimuli such as changes in light, temperature, moisture, animal feeding, and disease pressure. GAs stimulate seed germination in response to changes in light, temperature, and moisture (Koornneef and van der Veen, 1980; Yamauchi et al., 2004; Seo et al., 2009). GA also stimulates stem elongation and leaf expansion through cell expansion and cell division in response to light or dark (photomorphogenesis and skotomorphogenesis; Ogawa et al., 2003; Alabadí et al., 2008; Feng et al., 2008; de Lucas et al., 2008; Gallego-Bartolomé et al., 2011). GA stimulates developmental transitions from meristematic to shoot growth, from juvenile to adult leaf development, and from vegetative growth to flowering, and also stimulates aspects of flower development (Telfer et al., 1997; Yu et al., 2004; Galinha et al., 2009). The appropriate regulation of these events is essential to the survival of plant species and to successful crop production. GA stimulates many aspects of plant growth and development by lifting DELLA (Asp-Glu-Leu-Leu-Ala) protein repression of these events. This article will review multiple biochemical mechanisms for the regulation of and response to DELLA repression. Studies using plants with altered GA biosynthesis or catabolism have resulted in a wealth of knowledge of the diverse roles of GA in plant growth and development (for review, see Sun and Gubler, 2004; Yamaguchi, 2008). GA biosynthesis enzyme mutants of dicots and monocots are GA sensitive, showing defects in growth and development that are rescued by GA application. GA-sensitive mutants of rice (Oryza sativa) and barley (Hordeum vulgare) exhibit dwarfism, infertility, and failure to mobilize stored reserves during seed germination through a-amylase induction (Zwar and Chandler, 1995; Chandler and Robertson, 1999; Sakamoto et al., 2004). Similar phenotypes are seen in Arabidopsis (Arabidopsis thaliana) mutants affecting enzymes acting later in the biosynthesis pathway, GA 3-oxidase (GA3ox) and GA20ox (Hedden andPhillips, 2000; Plackett et al., 2012). Since GA3ox and GA20ox belong to multigene families, single mutants are fertile semidwarves. In Arabidopsis and tomato (Solanum lycopersicum), mutants affecting early GA biosynthesis enzymes such as ent-copalyl diphosphate synthase (Sun and Kamiya, 1994) cause failure in seed germination, growth as a dark green dwarf, failure to transition to flowering under short days, and partial to complete infertility (Koornneef and van der Veen, 1980; Karssen et al., 1989; Wilson et al., 1992). Overexpression of the gene encoding the GA catabolic enzyme GA2ox increases GA turnover, leading to reduced grain germination and a-amylase induction in wheat (Triticum aestivum; Appleford et al., 2007) and to failures in seed development and pollen tube growth in Arabidopsis (Singh et al., 2002). GA signaling is often controlled through direct regulation of hormone accumulation mediated by changes in GA20ox, GA3ox, and GA2ox expression in response to environmental or developmental stimuli. This is logical, as the hormone is the first step in a hormone signaling pathway. Stimulation of Arabidopsis seed germination by red light or cold imbibition and inhibition of germination by far-red light are associated with increased and decreased GA accumulation, respectively (for review, see Seo et al., 2009). Far-red light inhibits seed …