植物非编码RNA的研究进展

非编码RNA(non-coding RNA, ncRNA)是一类广泛存在于多种生物体中,缺乏明确的开放阅读框,不编码蛋白质的RNA分子.目前已从部分植物中分离到一些ncRNA,它们直接以RNA分子的形式在植物体内发挥重要的调节功能,影响细胞分化和个体发育、基因转录调控、mRNA稳定性、RNA加工与修饰、信号传导、以及环境适应调节等.植物ncRNA的研究为深入了解植物的生长发育及系统进化提供了重要信息.     

植物bHLH转录因子家族的功能研究进展

bHLH转录因子家族是植物转录因子中最大的家族之一。bHLH转录因子在真核生物的生长发育和调控中起到重要作用,其功能研究在动物中进展较快,而植物bHLH转录因子家族的功能只有部分得到解析。本文综述了bHLH转录因子家族在植物抗逆反应和生长发育中功能研究的最新进展,以期为进一步深入分析该家族基因在植物逆境胁迫应答中的作用提供帮助。     

The HCPro from the Potyviridae family: an enviable multitasking Helper Component that every virus would like to have

RNA viruses have very compact genomes and so provide a unique opportunity to study how evolution works to optimize the use of very limited genomic information. A widespread viral strategy to solve this issue concerning the coding space relies on the expression of proteins with multiple functions. Members of the family Potyviridae, the most abundant group of RNA viruses in plants, offer several attractive examples of viral factors which play roles in diverse infection‐related pathways. The Helper Component Proteinase (HCPro) is an essential and well‐characterized multitasking protein for which at least three independent functions have been described: (i) viral plant‐to‐plant transmission; (ii) polyprotein maturation; and (iii) RNA silencing suppression. Moreover, multitudes of host factors have been found to interact with HCPro. Intriguingly, most of these partners have not been ascribed to any of the HCPro roles during the infectious cycle, supporting the idea that this protein might play even more roles than those already established. In this comprehensive review, we attempt to summarize our current knowledge about HCPro and its already attributed and putative novel roles, and to discuss the similarities and differences regarding this factor in members of this important viral family.     

植物硫营养代谢、调控与生物学功能

植物作为无机硫的主要还原者,在全球的硫循环中起着关键作用。植物对土壤中硫酸盐的吸收运输和同化代谢,以及一系列具有重要生物学功能的含硫代谢产物的合成,不但与植物生长发育、耐逆和抗病虫害等密切相关,而且影响农作物产量与品质。硫营养的代谢和调控非常复杂,且生物学功能众多。本文综述了近年来植物硫营养代谢及调控及其在逆境胁迫中的生物学功能等方面的新进展,同时讨论了该领域悬而未决的重要生物学问题和研究动向,进而提出硫营养在农业生产上的重要性和所面临的新问题。     

植物硫营养代谢、调控与生物学功能

植物作为无机硫的主要还原者, 在全球的硫循环中起着关键作用。植物对土壤中硫酸盐的吸收运输和同化代谢, 以及一系列具有重要生物学功能的含硫代谢产物的合成, 不但与植物生长发育、耐逆和抗病虫害等密切相关, 而且影响农作物产量与品质。硫营养的代谢和调控非常复杂, 且生物学功能众多。本文综述了近年来植物硫营养代谢及调控及其在逆境胁迫中的生物学功能等方面的新进展, 同时讨论了该领域悬而未决的重要生物学问题和研究动向, 进而提出硫营养在农业生产上的重要性和所面临的新问题。     

Subtilases - versatile tools for protein turnover, plant development, and interactions with the environment

Subtilases (SBTs) constitute a large family of serine peptidases. They are commonly found in Archaea, Bacteria and Eukarya, with many more SBTs in plants as compared to other organisms. The expansion of the SBT family in plants was accompanied by functional diversification, and novel, plant-specific physiological roles were acquired in the course of evolution. In addition to their contribution to general protein turnover, plant SBTs are involved in the development of seeds and fruits, the manipulation of the cell wall, the processing of peptide growth factors, epidermal development and pattern formation, plant responses to their biotic and abiotic environment, and in programmed cell death. Plant SBTs share many properties with their bacterial and mammalian homologs, but the adoption of specific roles in plant physiology is also reflected in the acquisition of unique biochemical and structural features that distinguish SBTs in plants from those in other organisms. In this article we provide an overview of the earlier literature on the discovery of the first SBTs in plants, and highlight recent findings with respect to their physiological relevance, structure and function.     

The Akt kinases: Isoform specificity in metabolism and cancer

The Akt (PKB) protein kinases are critical regulators of human physiology that control an impressive array of diverse cellular functions, including the modulation of growth, survival, proliferation and metabolism. The Akt kinase family is comprised of three highly homologous isoforms: Akt1 (PKBα), Akt2 (PKBβ) and Akt3 (PKBγ). Phenotypic analyses of Akt isoform knockout mice documented Akt isoform specific functions in the regulation of cellular growth, glucose homeostasis and neuronal development. Those studies establish that the functions of the different Akt kinases are not completely overlapping and that isoform-specific signaling contributes to the diversity of Akt activities. However, despite these important advances, a thorough understanding about the specific roles of Akt family members and the molecular mechanisms that determine Akt isoform functional specificity will be essential to elucidate the complexity of Akt regulated cellular processes and how Akt isoform-specific deregulation might contribute to disease states. Here, we summarize recent advances in understanding the roles of Akt isoforms in the regulation of metabolism and cancer, and possible mechanisms contributing to Akt isoform functional specificity.     

Numerous isoforms of Fgf8 reflect its multiple roles in the developing brain

Soluble growth factors play an important role in the coordination and integration of cell proliferation, differentiation, fate determination, and morphogenesis during development of multicellular organisms. Fibroblast growth factors (FGFs) are a large family of polypeptide growth factors that are present in organisms ranging from nematodes to humans. RNA alternative splicing of FGFs and their receptors further enhances the complexity of this ligand-receptor system. The mouse Fgf8 gene produces eight splice variants, which encode isoform proteins with different N-termini and distinct receptor-binding affinity and biological activity. In this article, we review the roles of Fgf8 in vertebrate development and summarize the recent findings on the in vivo function of different Fgf8 splice variants. We propose that multiple Fgf8 isoform proteins act in concert to regulate the overall function of Fgf8 and account for the diverse and essential role of Fgf8 during vertebrate development.     

Formins in development: orchestrating body plan origami

Formins, proteins defined by the presence of an FH2 domain and their ability to nucleate linear F-actin de novo, play a key role in the regulation of the cytoskeleton. Initially thought to primarily regulate actin, recent studies have highlighted a role for formins in the regulation of microtubule dynamics, and most recently have uncovered the ability of some formins to coordinate the organization of both the microtubule and actin cytoskeletons. While biochemical analyses of this family of proteins have yielded many insights into how formins regulate diverse cytoskeletal reorganizations, we are only beginning to appreciate how and when these functional properties are relevant to biological processes in a developmental or organismal context. Developmental genetic studies in fungi, Dictyostelium, vertebrates, plants and other model organisms have revealed conserved roles for formins in cell polarity, actin cable assembly and cytokinesis. However, roles have also been discovered for formins that are specific to particular organisms. Thus, formins perform both global and specific functions, with some of these roles concurring with previous biochemical data and others exposing new properties of formins. While not all family members have been examined across all organisms, the analyses to date highlight the significance of the flexibility within the formin family to regulate a broad spectrum of diverse cytoskeletal processes during development.     

植物WRKY转录因子家族基因抗病相关功能的研究进展

植物基因组中,数目众多的转录因子参与植物的生长发育、物质代谢、响应生物和/或非生物胁迫等多种生物进程.WRKY基因家族是植物重要的转录因子家族,在抗病信号转导途径中起重要调控作用,因而成为分子植物病理研究领域中的热点.本文综述了WRKY转录因子基因在植物抗病反应中的作用和调节机制的最新研究进展,以期为深入研究WRKY基因家族在植物抗病反应中的作用,阐明植物抗病信号转导途径提供帮助.