植物气孔发育及其调控研究

气孔是植物与外界进行气体交换的通道。植物通过调节表皮气孔的开闭、大小和数目来优化气体的通过量,从而适应自身的生存环境。最近的研究工作揭示了控制气孔发育的基本遗传途径,以及环境信号如何调控气孔发育的基本遗传途径。文章总结了控制植物气孔发育基本途径的分子基础以及外界环境因素(主要是光和二氧化碳)与激素信号对气孔发育的调控机制,并对将来本领域需要解决的几个问题提出了看法。     

植物气孔发育机制研究进展

气孔是分布在植物表面的微孔, 是植物水分散失和与外界环境进行气体交换的门户。经过多年的研究, 气孔发育过程中重要调节因子陆续被发现。气孔复合体结构、发育起始模式以及在双子叶植物和单子叶植物中的分布都有较大差异。该文综述了双子叶植物拟南芥(Arabidopsis thaliana)气孔发育过程中调控因子、细胞极性分裂以及环境因子和植物激素调控气孔发育的机制; 还阐述了单子叶植物玉米(Zea mays)、二穗短柄草(Brachypodium distachyum)和水稻(Oryza sativa)气孔发育方面的研究进展, 并展望了气孔发育的研究方向。     

植物气孔发育的分子遗传调控

气孔广泛存在于植物地上组织和器官的表皮,是植物与外界环境进行气体交换的主要门户,调节光合作用和蒸腾作用等生理活动.原表皮细胞经过一系列固定的分裂和分化,最终产生成熟气孔.在气孔发育过程中,bHLH转录因子调控气孔细胞的起始、扩增和分化,受体-配体、MAPK信号级联介导的细胞间通讯确保正确的气孔发育图式的形成,极性蛋白调节气孔细胞不均等分裂的方向.此外,植物激素和环境因子也影响气孔发育.这些因子共同构建出植物气孔发育的分子遗传调控网络.本文综述了该网络及其最新研究进展     

水稻衰老调控机制研究取得重要进展

正植物的衰老受发育年龄和体内信号因子精确调节。脱落酸(ABA)是植物五大激素之一,参与众多的生物学过程,如促进种子休眠、提高耐逆性、调节气孔开关、促进叶片衰老等。在植物衰老时,体内ABA含量急剧升高,外源ABA也可诱导叶片衰老,因此,ABA被认为是一重要的衰老促进激素。然而,水稻中ABA合成和信号传导相关基因的突变体并未表现出延迟衰老的表型。因此,人们一直困惑ABA是如何参与调控植物的衰老进程。     

拟南芥根的辐射形态相关基因SHORT-ROOT研究进展

从模式植物拟南芥中克隆得到的SHORT-ROOT基因（SHR）被证明参与根部形态建成途径。目前已知SHR是与根辐射形态直接相关的重要调控因子,同时也参与维持根尖分生组织的活性。SHR既作为转录因子启动下游基因的表达,又作为短程信号调节根的发育。本文综述了SHR相关研究进展,并展望其研究前景。     

拟南芥根的辐射形态相关基因SHORT-ROOT 研究进展

从模式植物拟南芥中克隆得到的SHORT-ROOT基因(SHR)被证明参与根部形态建成途径。目前已知SHR是与根辐射形态直接相关的重要调控因子, 同时也参与维持根尖分生组织的活性。SHR既作为转录因子启动下游基因的表达, 又作为短程信号调节根的发育。本文综述了SHR相关研究进展, 并展望其研究前景。     

植物气孔发育的分子调控机制

气孔是陆生植物表皮上可以调节的小孔,也是植物进行气体交换的主要通道。气孔不仅对植物的光合作用起着非常关键的作用,而且对全球的碳循环和水循环具有重要的影响。气孔分布和形态结构在单、双子叶植物间也有较大的差异,这些差异因植物种类不同影响着气孔发育的精细调控。本文综述了调控气孔前体细胞命运的分子网络、细胞极性分裂和表观遗传机制,归纳了外界环境信号通过与内源信号通路互作介导气孔发育的过程,提出了气孔发育基于多水平控制的气孔发育模型。     

生长素调控植物气孔发育的研究进展

气孔是分布于植物表皮由保卫细胞围成的小孔, 是植物体与外界环境进行水分和气体交换的重要通道, 通过影响光合作用、蒸腾作用及一系列生物学过程来促进植物适应环境的变化。生长素是最早被发现的植物激素, 在植物生长发育中发挥重要作用。近年来的研究表明, 生长素通过载体蛋白-TIR1/AFB受体-AUXIN/IAA-ARFs信号通路, 调控STOMAGEN的表达; 之后, 经STOMAGEN-类LRR受体蛋白激酶ERf-MAPKs级联反应激酶-SPCH转录因子信号通路, 启动气孔的发育进程。EPF1、EPF2和类LRR受体蛋白激酶TMM不是该过程的必需元件。生长素对气孔的调控受光信号影响, 光信号通路组分E3泛素连接酶COP1位于MAPKs激酶的上游, 参与气孔的发育调控。     

气孔发育机制及其内外调控因子的研究进展

气孔是植物与外界环境进行气体与水分交换的重要通道,调节着植物的蒸腾与光合作用。在长期进化过程中,植物通过调节气孔行为和气孔发育机制来适应环境变化。不同植物气孔系的形成方式不尽相同,但过程均受到气孔发育信号网络系统的调节作用。近年来关于气孔发育机制的研究层出不穷,现重点综述各类转录因子、信号肽以及环境因子和植物激素对气孔发育的调节作用。该领域的研究为在微观层面揭示植物对环境变化的适应机制提供了科学基础。     

植物BBX转录因子基因家族的研究进展

转录因子在调控植物生长、发育及环境适应性等方面发挥重要作用。具有B-box结构域的一类锌指结构转录因子称为BBX,它们通过调控基因转录,与同类或其他转录因子的互作参与植物光形态建成、花发育、避荫效应、植物信号转导以及非生物和生物逆境响应等。文中从BBX蛋白结构、分类以及其功能方面对该类转录因子在植物中的作用进行了综述。     

Regulation Mechanisms of Stomatal Oscillation

Stomata function as the gates between the plant and the atmospheric environment. Stomatal movement, including stomatal opening and closing, controls CO2 absorption as the raw material for photosynthesis and water loss through transpiration. How to reduce water loss and maintain enough CO2 absorption has been an interesting research topic for some time. Simple stomatal opening may elevate CO2 absorption, but, in the meantime, promote the water loss, whereas simple closing of stomatal pores may reduce both water loss and CO2 absorption, resulting in impairment of plant photosynthesis. Both processes are not economical to the plant. As a special rhythmic stomatal movement that usually occurs at smaller stomatal apertures, stomatal oscillation can keep CO2 absorption at a sufficient level and reduce water loss at the same time, suggesting a potential improvement in water use efficiency. Stomatal oscillation is usually found after a sudden change in one environmental factor in relatively constant environments. Many environmental stimuli can induce stomatal oscillation. It appears that, at the physiological level, feedback controls are involved in stomatal oscillation. At the cellular level, possibly two different patterns exist： （i） a quicker responsive pattern; and （ii） a slower response. Both involve water potential changes and water channel regulation, but the mechanisms of regulation of the two patterns are different. Some evidence suggests that the regulation of water channels may play a vital and primary role in stomatal oscillation. The present review summarizes studies on stomatal oscillation and concludes with some discussion regarding the mechanisms of regulation of stomatal oscillation.     

Stomatal Density and Bio-water Saving

Bio-water saving is to increase water use efficiency of crops or crop yield per unit of water input. Plant water use efficiency is determined by photosynthesis and transpiration, for both of which stomata are crucial. Stomata are pores on leaf epidermis for both water and carbon dioxide fluxes that are controlled by two major factors： stomatal behavior and density. Stomatal behavior has been the focus of intensive research, while less attention has been paid to stomatal density. Recently, a number of genes controlling stomatal development have been identified. This review summarizes the recent progress on the genes regulating stomatal density, and discusses the role of stomatal density in plant water use efficiency and the possibility to increase plant water use efficiency, hence bio-water saving by genetically manipulating stomatal density.     

Stomatal Density and Bio-water Saving

Bio-water saving is to increase water use efficiency of crops or crop yield per unit of water input. Plant water use efficiency is determined by photosynthesis and transpiration, for both of which stomata are crucial. Stomata are pores on leaf epidermis for both water and carbon dioxide fluxes that are controlled by two major factors: stomatal behavior and density. Stomatal behavior has been the focus of intensive research, while less attention has been paid to stomatal density. Recently, a number of genes controlling stomatal development have been identified. This review summarizes the recent progress on the genes regulating stomatal density, and discusses the role of stomatal density in plant water use efficiency and the possibility to increase plant water use efficiency, hence bio-water saving by genetically manipulating stomatal density.     

土壤干旱胁迫下非水力根信号调控夏玉米气体交换对大气环境的响应

对不同程度土壤干旱胁迫下夏玉米非水力根信号的产生以及气体交换过程对大气环境的响应进行了试验研究。充足底墒播种后采用3个土壤水分处理等级(0~200cm土壤相对湿度为>80%、60%~70%、40%~50%,代号为W T1、W T2和W T3)。生育期内遮去自然降水。试验结果表明,在拔节期轻度和中度土壤干旱胁迫的情况下,玉米根系合成大量ABA传输到地上部分,参与控制气孔开度和气体交换过程对大气环境变化的响应并调节水分消耗。在日变化过程中,当光强和水汽压亏缺较高时,由于蒸腾速率较高,非水力根信号物质向冠层的传输速率也较高,ABA在叶片中的累积影响了气孔开张对光强响应的敏感度,气孔开度受到抑制,并且随着ABA累积和浓度的增加,气孔抑制作用越强;在水汽压亏缺较低的情况下,非水力根信号物质向冠层的传输速率较低,ABA的代谢过程以及再分配过程能够保证这种信号物质保持在低水平,从而保证一定程度的气孔开度和光合、蒸腾速率。这种策略能够使夏玉米在轻、中等干旱条件下保证最大的光合作用,同时在可能的胁迫情况下降低蒸腾作用以提高水分利用效率。     

Plant development: YODA the stomatal switch

The appearance of stomatal pores during plant evolution is believed to have been a crucial step in land colonisation. A recent screen for genes involved in stomatal development has identified for the first time a mutant plant with no stomata; the results implicate a MAP kinase cascade in stomatal development.     

低空气湿度下气孔运动的调控

植物气孔应答气候环境因子的机制,一直是植物抗逆生理研究领域的热点课题。空气湿度是主要的气候环境因子之一,人们很早就发现降低空气湿度能导致气孔开度变小,但到目前为止,对调控这一生物学过程的机制还知之甚少。本文概述近年来在植物气孔应答低空气湿度信号的运动规律、水被动反馈假说、水主动反馈假说、水力调节与代谢调节的关系等方面的进展,并基于进化学的理论,提出了水力调节和代谢调节的反向消长模式,以期解释大量物种气孔对低空气湿度的不同应答反应。     

Blue light inhibits stomatal development in soybean isolines containing kaempferol-3-O-2G-glycosyl-gentiobioside (K9), a unique flavonoid glycoside

Stomata have a fundamental role in controlling plant photosynthesis and transpiration, but very little is known about factors controlling stomatal differentiation and development. Lines of soybean that contain a specific flavonol glycoside, kaempferol‐3‐O‐2‐glycosyl‐gentiobioside (K9), as well as greatly reduced stomatal density, especially on the adaxial epidermis, have been identified. The specific effects of blue light photoreceptors on stomatal development in K9 lines and their isoline pairs containing no K9 were studied. Low irradiances of blue light (7% of total photosynthetically active radiation) added to high irradiances from low‐pressure sodium lamps strongly inhibited stomatal development on the adaxial epidermis of K9 lines, but not in isoline pairs differing putatively in only one gene and lacking K9. Overall, blue light slightly increased stomatal density on the abaxial epidermis in all isolines, demonstrating differential regulation of stomatal development in the upper and lower epidermis. Blue light also caused an increase in leaf area in all isolines, indicating that changes in stomatal density were not the non‐specific result of alterations in leaf area. Morphological studies revealed that the blue light‐induced reduction in stomatal density in K9 lines was due to reduced stomatal initiation as well as aborted or abnormal stomatal development. As the phytochrome photostationary state was kept constant, the results indicate that one or more blue light receptors are involved in the control of stomatal development. This system should be useful for the study of mechanisms controlling stomatal development, even if the photo‐inhibitory response is unique to K9 lines.     

单细胞组学技术及其在植物保卫细胞研究中的应用

单细胞组学技术在动物研究中已经得到广泛应用,但在植物学领域尤其是保卫细胞研究中还处于起步阶段。由保卫细胞构成的气孔承担着植物生命过程中水分散发及气体交换大门的作用。将单细胞组学技术应用到保卫细胞功能解析中将有助于了解保卫细胞参与的基本生理过程。该文综述了植物单细胞组学技术的发展、保卫细胞研究现状及单细胞组学技术在植物保卫细胞研究中的初步应用,为借助该技术解决植物生物学中保卫细胞发育、代谢及对环境胁迫响应等基本问题提供研究思路和方法。