生长素的运输及其在信号转导及植物发育中的作用

生长素作为一种重要的植物激素,参与调节植物生长发育的诸多过程,如器官发生、形态建成、向性反应、顶端优势及组织分化等,其作用机理长期以来备受人们关注。生长素的极性运输能使生长素积累在植物体某些特定部位,从而形成生长素浓度梯度,生长素对植物生长发育的调节主要依赖于这一特性。系统阐述生长素的运输特点、运输机理和相关生长素极性运输载体的研究进展;并对生长素信号转导途径中的重要组分及其机理进行了总结;同时较系统地对生长素参与植物体各器官发育过程及调节情况进行综述。     

植物生长素的极性运输载体研究进展

生长素极性运输在植物生长发育中起重要的调控作用.植物细胞间的生长素极性运输主要通过生长素运输载体进行调控.该文对近年来有关生长素极性运输载体,包括输入载体AUX/LAX、输出载体PIN、尤其是新近发现的兼有输入和输出载体功能的MDR/PGP等蛋白家族,以及生长素极性运输中PIN与MDR/PGP蛋白间相互作用关系进行综述.     

生长素极性运输研究进展

生长素极性运输与植物生长发育密切相关并受许多因素调控,生长素极性运输机理方面已取得较大进展,但仍有一些亟待解决的问题.研究植物生长素极性运输的生理机制及其调控具有十分重要的意义.通过了解生长素在植物生长发育中的作用,进而阐述生长素极性运输机理方面的研究进展.     

生长素的极性运输及其在植物发育调控中的作用

生长素是已知的植物激素中唯一具有极性运输方式的激素。利用生长素极性运输抑制物和生长素极性运输突变体,使人们获得大量有关生长素及其极性运输在植物生长发育调控中具有重要作用的资料。与生长素极性运输有关的基因的克隆及其表达调控的研究将进而在分子水平上阐明其作用的机理。     

生长素极性运输研究进展

高等植物的生长发育受激素的广泛调控,其中生长素的作用尤为独特,因为生长素在植物组织内的浓度梯度是由其极性运输维持的,而正是激素在植物组织的相对含量决定了该组织的发育命运。高等植物体内存在可运输的化学信使的概念首先由Ｄａｒｗｉｎ父子提出。通过对金丝鸟木亡草（Ｐｈａｌａｒｉｓｃａ ｎａｒｉｅｎｓｉｓ）幼苗的向光性的研究,他们认为植物的向光性受到一种可运输的物质的调控［1］。后来发现这一物质是生长素,在自然界中主要存在的形式是ＩＡＡ。到本世纪 30年代,禾谷类植物中的生长素的极性运输得到证实,后来发现所有…     

植物向重力反应中PIN-FORMED介导的生长素极性运输调控

植物的向性,即植物对光或重力等环境刺激信号产生的定向生长反应。在向重力性反应中,植物器官将重力感知为定向环境信号,来控制其器官的生长方向以促进生存。植物激素生长素及其极性运输在植物向重力反应中起着决定性的调控作用。质膜定位的生长素输出蛋白PIN-FORMED(PIN)通过动态的亚细胞极性定位,改变生长素运输的方向以响应环境刺激,由此植物器官间建立的生长素浓度梯度是细胞差异化伸长和器官弯曲的基础,来调控植物的形态建成和生长发育过程。本文主要讨论发生在植物重力感受细胞内早期重力感知和信号转导机制的最新研究进展、PIN介导的生长素极性运输、PIN的极性定位以及质膜蛋白丰度的调控机制等。     

拟南芥根中生长素极性运输的研究进展

生长素极性运输影响植物的生长和发育,在植物器官形态建成、发育等过程中发挥重要的调控作用.生长素极性运输是一个依赖于生长素运输载体来完成的复杂过程.近年来生长素极性运输载体AUX/LAX蛋白、PIN蛋白家族和MDR/PGP蛋白家族在生长素极性运输中作用的研究日益深入,并且在植物激素联系和转运方面取得了重大发现——PILC蛋白.     

植物生长素极性运输调控机理的研究进展

生长素极性运输特异地调控植物器官发生、发育和向性反应等生理过程。本文综述和分析了生长素极性运输的调控机制。分子遗传和生理学研究证明极性运输这一过程是由生长素输入载体和输出载体活性控制的。小G蛋白ARF附属蛋白GEF和GAP分别调控输出载体（PINI）和输入载体（AUX1）的定位和活性。并影响高尔基体等介导的细胞囊泡运输系统,小G蛋白ROP也参与输出载体PIN2活性的调节。本文基于作者的研究工作提出小G蛋白在调控生长素极性运输中的可能作用模式。     

植物生长素极性运输调控机理的研究进展

生长素极性运输特异地调控植物器官发生、发育和向性反应等生理过程。本文综述和分析了生长素极性运输的调控机制。分子遗传和生理学研究证明极性运输这一过程是由生长素输入载体和输出载体活性控制的。小G蛋白ARF附属蛋白GEF和GAP分别调控输出载体(PIN1)和输入载体(AUX1)的定位和活性, 并影响高尔基体等介导的细胞囊泡运输系统, 小G蛋白ROP也参与输出载体PIN2活性的调节。本 文基于作者的研究工作提出小G蛋白在调控生长素极性运输中的可能作用模式。     

ABI4调控侧根发育研究(综述)

生长素是调控植物侧根发育的关键植物激素,生长素运输载体PIN蛋白介导其极性分布。ABI4抑制生长素极性运输蛋白基因PIN1的表达,影响生长素的极性运输,抑制侧根形成。本文概述ABI4转录因子调控侧根发育的研究进展。     

Cell-type action specificity of auxin on Arabidopsis root growth

The plant hormone auxin plays a critical role in root growth and development; however, the contributions or specific roles of cell-type auxin signals in root growth and development are not well understood. Here, we mapped tissue and cell types that are important for auxin-mediated root growth and development by manipulating the local response and synthesis of auxin. Repressing auxin signaling in the epidermis, cortex, endodermis, pericycle or stele strongly inhibited root growth, with the largest effect observed in the endodermis. Enhancing auxin signaling in the epidermis, cortex, endodermis, pericycle or stele also caused reduced root growth, albeit to a lesser extent. Moreover, we established that root growth was inhibited by enhancement of auxin synthesis in specific cell types of the epidermis, cortex and endodermis, whereas increased auxin synthesis in the pericycle and stele had only minor effects on root growth. Our study thus establishes an association between cellular identity and cell type-specific auxin signaling that guides root growth and development.     

A Role for Auxin in Flower Development

Auxin has long been implicated in many aspects of plant growth and development including flower development. However, the exact roles of auxin in flower development have not been well defined until the recent identification of auxin biosynthesis mutants. Auxin is necessary for the inltiation of floral primordia, and the disruption of auxin biosynthesis, polar auxin transport or auxin signaling leads to the failure of flower formation. Auxin also plays an essential role in specifying the number and Identity of floral organs. Further analysis of the relationship between the auxin pathways and the known flower development genes will provide critical information regarding mechanisms of organogenesis and pattern formation in plants.     

Channelling auxin action: modulation of ion transport by indole-3-acetic acid

The growth hormone auxin is a key regulator of plant cell division and elongation. Since plants lack muscles, processes involved in growth and movements rely on turgor formation, and thus on the transport of solutes and water. Modern electrophysiological techniques and molecular genetics have shed new light on the regulation of plant ion transporters in response to auxin. Guard cells, hypocotyls and coleoptiles have advanced to major model systems in studying auxin action. This review will therefore focus on the molecular mechanism by which auxin modulates ion transport and cell expansion in these model cell types.     

Auxin receptors: recent developments

Rapid advances have been made in the study of auxin binding proteins (ABPs) in the last five years. In particular, an ABP in maize membranes has been cloned, sequenced and both monoclonal and polyclonal antibodies to this ABP have been developed. Structural and functional analysis has begun and there is good electrophysiological evidence that ABP in the plasma membrane functions as a receptor, probably involved in auxin-induced cell expansion. The role of the large amount of ABP in the endoplasmic reticulum is less clear, as is the relationship to soluble ABPs. At present there is only some circumstantial evidence relating any ABP to cell division. Receptors for synthetic inhibitors of auxin transport (phytotropins) are also of interest in relation to auxin action, but are less well characterised. Identification of new naturally-occurring phytotropins could lead to novel plant growth regulators.     

Polar auxin transport – old questions and new concepts?

Polar auxin transport controls multiple aspects of plant development including differential growth, embryo and root patterning and vascular tissue differentiation. Identification of proteins involved in this process and availability of new tools enabling `visualization' of auxin and auxin routes in planta largely contributed to the significant progress that has recently been made. New data support classical concepts, but several recent findings are likely to challenge our view on the mechanism of auxin transport. The aim of this review is to provide a comprehensive overview of the polar auxin transport field. It starts with classical models resulting from physiological studies, describes the genetic contributions and discusses the molecular basis of auxin influx and efflux. Finally, selected questions are presented in the context of developmental biology, integrating available data from different fields.     

生长素介导环境信号调控植物的生长发育

植物是一类营固着生活的自养型生物, 如何更好地适应周围环境对植物的生存至关重要。生长素是调控植物生长发育的重要激素之一。近年来的研究发现, 生长素不仅能够响应内在的发育信号, 而且能够介导各种环境信号, 参与植物生长发育和生长反应的调控。该文主要从光信号、温度信号、重力信号、营养元素和金属离子信号等方面重点阐述生长素如何介导上述各种不同的环境信号, 从而调控植物的生长发育。