狭基巢蕨叶表皮的结构和气孔器发育的观察

狭基巢蕨Ｎｅｏｔｏｐｔｅｒｉｓａｎｔｒｏｐｈｙｏｉｄｅｓ（Ｃｈｒｉｓｔ）Ｃｈｉｎｇ叶片的上表皮无气孔器,仅具表皮细胞,下表皮由表皮细胞和气孔器组成,气孔指数为２．５。上下表皮细胞和气孔器的细胞中均含有叶绿体。每个气孔器由２个肾形的保卫细胞和２～６个副卫细胞组成,其中以３个和４个副卫细胞的占绝大多数（３细胞的占４５．１％,４细胞的占４３．５％）。从发育上看,气孔器原始细胞进行２次分裂,产生２个保卫细胞和１个同源的副卫细胞。气孔器的发育过程大体可分为４个时期：（１）气孔器原始细胞的分化和分裂期;（２）保卫细胞母细胞成熟期;（３）保卫细胞母细胞分裂和气孔器幼期;（４）气孔器成熟期。狭基巢蕨的气孔器属于中周型     

STOMATAL MECHANICS

A model of stomatal movement due to changes in turgor is presented which systematically illustrates the role of certain anatomical features. During the expansion of paired guard cells, there are two physical constraints that cause the guard cells to bend and thus open the stomatal pore. The radial orientation of the micellae is shown to be the crucial feature which directly transmits the movement of the dorsal wall of the polar and central section to the stomatal slit. Furthermore, it is necessary that either the overall length of the entire stomatal apparatus or length of the common wall between the polar segments of the guard cells be constrained during the expansion of the guard cells. The model also shows that asymmetrically thickened guard cell walls are not necessary to cause bending of the guard cell. The ideas set forth in our model are consistent with the opening movements of both elliptical and grass-type stomata.     

蚕豆气孔运动中水通道和离子通道的作用和地位的探讨

 用不同浓度HgCl2、LaCl3和TEACl (Tetraethylammonium chloride)处理蚕豆(Vicia faba)叶片下表皮条,发现HgCl2能显著抑制气孔开闭,Ca2+通道阻塞剂LaCl3或K+通道阻塞剂TEACl处理也都有一定程度的抑制。三者的作用效果HgCl2>>LaCl3>TEACl。用HgCl2+LaCl3、HgCl2+TEACl或HgCl2+LaCl3+TEACl处理,则气孔开闭运动几乎完全被抑制。表明：蚕豆气孔运动中,保卫细胞胀缩主要是水通道直接参与保卫细胞与叶肉细胞间水流的调节引起的,离子通道起间接次要作用,二者共同引起保卫细胞体积变化而导致气孔开闭。     

VARIATION OF STOMATAL DISTRIBUTION IN CAREX AQUATILIS (CYPERACEAE)

The density and distribution of stomates in Carex aquatilis Wahl. in the Pacific Northwest were examined using epidermal peels of samples of leaves from natural populations, from greenhouse-grown transplants and from seedling families grown under controlled conditions. These were compared to stomatal distributions of populations in eastern North America. Populations of Carex aquatilis Wahl. form 2 groups based on the distribution and density of stomates. Carex aquatilis var. dives (Holm) Kükenthal is epistomatic, with adaxial stomatal densities of 28.7–48.5/0.1 mm². The C. aquatilis var. aquatilis is amphistomatic, with adaxial stomatal densities of 8.1–22.2/0.1 mm² and abaxial densities of 11.3–24.5/0.1 mm² in the Pacific Northwest. Total stomatal frequencies are similar in both groups. Stomatal distribution and densities are here shown to not vary significantly within populations and appear to be genetically determined, as shown by progeny tests and growth of seedlings under uniform and experimental conditions. Stomatal distribution in Carex aquatilis appears to be adaptive, and intraspecific variation provides a system for determining the adaptive significance of differences in stomatal patterns.     

CHANGED ORIENTATION OF THE MITOTIC SPINDLE OF STOMATAL GUARD CELL DIVISIONS IN HORDEUM VULGARE

Three-day-old seedlings of ‘Atlas’ barley were treated for 1 hr with an aqueous solution of 2-mercaptoethanol at various concentrations. This caused a general delay of mitosis, suppression of subsidiary cell formation in manystomatal complexes, and complete inhibition of the formation of some stomatal complexes. In a small proportion of stomatal complexes the orientation of the division of the guard cell mother cell was changed so that its mitotic spindle was no longer transverse but parallel to the long axis of the leaf and produced daughter cells proximally and distally to each other. The highest frequency of such proximal-distal orientations, a mean of 2.23 per stomatal row, was produced by concentrations of 0.175–0.2 m. Proximal-distal reorientations were concentrated in a region of the leaf distal to that in which the greatest inhibition of stomatal complexes occurred. Susceptible complexes were those at early stages of subsidiary formation when exposed to mercaptoethanol; this is long before prophase of GCMC division. The mean length/width ratio of cells at this stage was significantly greater in treated than in control material. Gibberellic acid at 550 ppm significantly increased both the 1/w ratio and the frequency of proximal-distal divisions. A much higher proportion of proximal-distal divisions was obtained in upper leaf sheaths excised and placed for 24 hr in a moist atmosphere. This effect was associated with a period of quiescence following excision, after which mitoses were resumed, many of them with proximal-distal reorientation.     

毛竹(Phyllostachys pubescens)叶光合作用的气孔限制研究

运用Farquhar和Sharkey(1982)提出的两个判据——细胞间隙CO_2浓度(C_i)和气孔限制值(L_s),从几个不同的侧面研究了毛竹光合作用的气孔限制。虽然观测到气孔导度(G_s)与光合速率(P_n)随着气温、光量子通量密度的降低和叶水分胁迫的加剧而大体上平行地下降,但是在低的环境温度、低的光量子通量密度和严重的水分胁迫下,气孔导度的下降不是光合速率下降的主要原因,因为这时C_i在上升,而L_s下降。然而,在低的空气湿度和轻微水分胁迫下,C_i的下降和L_s的上升都证明,这时气孔导度的下降是光合速率降低的主要原因。     

THE MECHANISM OF STOMATAL MOVEMENT

Ketellapper , H. J. (California Inst. Tech., Pasadena.) The mechanism of stomatal movement. Amer. Jour. Bot. 46(3) : 225-231. IIlus. 1959.—A review of the pertinent literature reveals that fairly exact knowledge is available about the effects of light, CO₂, and water content of the leaf on stomatal movement. Two distinct types of light action can be distinguished: an indirect effect, mediated through photosynthesis and the resulting lower CO₂ concentration within the leaf, and a direct effect which occurs even when the intercellular spaces are washed out with CO₂-free air. The CO₂ concentration occupies a very central position in the regulation of stomatal movement. The action of CO₂ and light will be influenced, or even counteracted, by the value of the water deficit in the leaf. A large number of changes in the guard cells, accompanying stomatal movement, has been described in the literature and some of these have been discussed in the present review: for example, the changes in osmotic value, in starch content, and in permeability. These observations led to the formulation of the classical theories of stomatal movement. It has been concluded that the classical theories are not adequate to explain stomatal movement. At present one can choose between 2 alternatives: an osmotic theory incorporating the pathways of the classical theories and bringing these together in one general scheme hinging on the sugar-starch conversion, or else a theory incorporating non-osmotic processes for the removal of water or osmotic active material. These alternatives have been discussed in some detail. It has been concluded that more experimental evidence is required before a valid theory of stomatal movement can be brought forward.     

STRUCTURE AND ONTOGENY OF THE STOMATAL COMPLEX IN PINUS STROBUS L. AND PINUS BANKSIANA LAMB.

The morphology of the stomatal complex in Pinus strobus L. and P. banksiana Lamb, is described and it is proposed that the stomatal complex should be considered an eight-celled complex consisting of two guard cells, and two polar, two lateral, and two hypodermal subsidiary cells. An ontogenetic study found these cells closely related developmentally. It was also found that the stomatal complex in these two pines could not readily be classified as haplocheilic because a polar subsidiary cell arises from the same protodermal cell as does the guard cell mother cell. A modification of the classical concept of stomatal development was necessary to describe the stomata as eumesoperigenous.     

ABNORMAL STOMATAL DEVELOPMENT IN FOLIAGE LEAVES OF BEGONIA ARIDICAULIS

Dehnel , George S. (U. Missouri, Columbia.) Abnormal stomatal development in foliage leaves of Begonia aridicaulis. Amer. Jour. Bot. 48(2): 129–133. Illus. 1961.—The results of 2 types of aberrant stomatal development in abaxial epidermis of normal laminae of B. aridicaulis are discussed and illustrated. The more common is a so-called persistent stomatal initial that is an essentially circular cell (in face view) with chloroplasts and a wall of uniform thickness. The other type of anomalous development yields a single guard cell, which possesses chloroplasts, differential wall thickening, rarely a pore, and a form characteristic of a normally paired guard cell. Both types of cells may either be isolated or occur variably in close relationship to normal stomata.     

RAISED STOMATAL CLUSTERS ON COLEUS (LAMIACEAE) STEMS

Stomata on stem internodes of Coleus blumei occur only in clusters on hollow epidermal bulges. We illustrate them here with light and scanning electron microsocpy. Some stomatal clusters are sites for lenticel formation on older internodes. Three Plectranthus species were also examined; two had discrete stomatal clusters while the third showed a more scattered arrangement of stomata, indicating that the stomatal pattern on stems may have some potential as a taxonomic character in Lamiaceae.     

植物气孔导度的机理模型

Ball-Berry气孔导度模型及其修正模型是评价植物叶片气孔调节的重要工具。该文从CO₂分子在叶片气孔中扩散这个最基本的物理过程出发, 应用物理学中的分子扩散和碰撞理论、流体力学与植物生理学等知识, 严格推导出叶片气孔导度的机理模型。利用美国Li-Cor公司生产的Li-6400光合作用测定仪控制CO₂浓度、湿度和温度, 测量了华北平原冬小麦(Triticum aestivum)的光响应数据和气孔导度数据。拟合结果表明: 推导的气孔导度机理模型较之Ball-Berry气孔导度模型和Tuzet等气孔导度模型, 能更好地描述冬小麦的气孔导度与净光合速率之间的关系。如果用气孔导度的机理模型耦合光合作用对光响应的修正模型, 则耦合模型可以很好地描述华北平原冬小麦叶片气孔导度对光强的响应曲线, 并可直接估算冬小麦的最大气孔导度和对应的饱和光强, 同时可以研究最大气孔导度是否与最大净光合速率同步的问题。拟合结果还表明: 冬小麦在30 ℃、560 μmol·mol^-1CO₂, 或在32 ℃、370 μmol·mol^-1CO₂条件下, 最大气孔导度与最大净光合速率并不同步。     

STOMATAL BEHAVIOR OF AVENA SATIVA TREATED WITH TWO PHYTOTOXINS,VICTORIN AND FUSICOCCIN

The transpiration and stomatal behavior of blight-susceptible and blight-resistant oats (Avena sativa L.) were followed after treatment with victorin, the host-specific toxin of Helminthosporium victoriae, and fusicoccin, the toxin produced by Fusicoccum amygdali. Victorin, at 0.012 units/ml and greater, significantly decreased the transpiration of the blight-susceptible variety in 3 hr, but had no effect on the transpiration of the blight-resistant variety. The stomatal resistance, measured with a ventilated diffusion porometer, showed that the decrease in transpiration was caused by stomatal closure; the greater the concentration of victorin the earlier the stomata closed. At high concentrations of victorin the stomata reopened in the blight-susceptible variety, and partial stomatal closure was observed in the resistant variety. Inactivated toxin had no effect on the stomata of either oat variety. When fusicoccin and victorin were compared under the same environmental conditions, victorin closed the stomata of the blight-susceptible leaves, whereas fusicoccin opened the stomata in both the blight-susceptible and resistant leaves. It is concluded that the two toxins differ in their effects on the guard cells; their possible modes of action are discussed.     

Studies in Stomatal Behaviour: VII. EFFECTS OF ANAEROBIC CONDITIONS UPON STOMATAL MOVEMENT--A TEST OF WILLIAMS'S HYPOTHESIS OF STOMATAL MECHANISM

An experiment was carried out to investigate stomatal responsesin wheat to four ‘closing treatments’, viz. highcarbon dioxide concentration, darkness, dry air and nil, eachgiven under both aerobic and anaerobic conditions. Thus theeffect of lack of oxygen on the closing (or opening) tendencywas estimated. Changes in calculated from resistance porometer readings were used as data and reasonsare given for thinking this is the best available measure forinvestigating stomatal dynamics in wheat. Williams's hypothesisdemands that lack of oxygen should cause stomatal opening orprevent closure; the present experiment shows that anaerobicconditions significantly increase the closing tendency when‘closing treatments’ are first applied. There isalso some suggestion that oxygen-lack itself tends to causeclosure in the absence of any other ‘closing treatment’.Williams's hypothesis in its original form is thus disproved(for wheat) but the present results would be consistent withan ‘active’ uptake of water by the guard cells contributingto stomatal opening. A nearly significant interaction betweencarbon dioxide and oxygen suggests that under anaerobic conditionsa ‘closing substance’ may perhaps be formed, forexample, by the union of some intermediate in glycolysis withcarbon dioxide.     

THE ULTRASTRUCTURAL CYTOLOGY OF THE DIFFERENTIATING GUARD CELLS OF VIGNA SINENSIS

Structural differentiation of the guard cells of Vigna sinensis results from the integration of the following interrelated processes: a) intense activity of ribosomes, dictyosomes, endoplasmic reticulum (ER) membranes and mitochondria and patterned organization of microtubules; b) unequal thickening and ordered micellation of their walls and opening of the stomatal pore; and c) the divergent differentiation of the plastids. In differentiating guard cells, microtubules appear anticlinally oriented and more or less evenly distributed along the unthickened part of the dorsal wall and in the middle part of the ventral wall where thickening of the future pore occurs. In periclinal walls, microtubules fan away from the margins of the increasing thickening of the ventral wall and, later, from the rims of the stomatal pore towards the dorsal walls, parallel to the depositing radial microfibrils. Microtubules may be the cytoplasmic elements underlying guard-cell morphogenesis. Although cell-plate organization in guard-cell mother cells does not seem to differ from that of other protodermal cells, the middle lamella of the ventral wall becomes electron-translucent. The stomatal pore develops schizogenously from the internal and/or external ends of the ventral wall and proceeds inwards, remaining incomplete in most of the stomata of plants grown for 30 days in darkness and in some malformed ones which were developed after a prolonged action of colchicine. The guard cell, when approaching maturity, loses its organelle complexity and plasmodesmata, but it keeps a significant portion of its cytoplasm and organelles. Perigenous stomata generally exceed the size of mesoperigenous and mesogenous ones, develop large vacuoles and appear able to induce oriented divisions in their vicinity.     

甲醇对蚕豆气孔开启的影响

在一定的深度范围内,甲醇能促进蚕豆气孔的开启,最适浓度为１．５％,与６－苄基腺嘌呤（６－ＢＡ）有协同增效作用,对脱落酸（ＡＢＡ）有拮抗作用。     

微管在气孔运动中的作用

用植物微管专一性解聚剂甲基胺草磷(APM)预处理蚕豆(Vicia faba L.)下表皮,再用诱导气孔运动的因子处理,在显微镜下观察气孔孔径的变化。结果显示,用50mg/L APM预处理开放或关闭状态气孔,虽胞质微管被解聚,但气孔孔径没有发生明显的变化,表明胞质微管与开放或关闭状态气孔的维持无关;而去掉APM后,CaCl_2可在4h内诱导气孔关闭,气孔的运动功能又可恢复。进一步的研究表明,开放气孔经APM预处理60min后,再用ABA、Ca~(2 )及暗处理均不能诱导气孔关闭,表明微管可能参与了ABA、Ca~(2 )及暗诱导的气孔关闭过程;关闭气孔经50mg/L APM预处理后,光诱导气孔开度较不经 APM处理的有明显差异,且随着APM预处理时间和浓度的变化,气孔开放程度亦不同,表明微管也参与了光诱导的气孔开放过程。     

根源ABA参与气孔调节的数学模拟

建立了包括植物体内的水分传输,并有根源ABA参与的气孔调节模型,模拟了饱和水气压差(VPD)、气温、表层土壤含水量(θ_(s1))等环境因子对叶片水势、木质部汁液中ABA浓度([ABA]_x)及气孔导度的影响。结果显示,VPD和气温的变化能够改变叶片水势及气孔导度;[ABA]_x几乎不受VPD和气温变化的影响,却决定着叶片水势及气孔导度对VPD和气温变化的响应幅度;θ_(s1)影响[ABA]_x,并由此影响气孔导度,但相比之下对叶片水势的作用并不显著。     

GFP-mTn融合蛋白对蓝猪耳生活细胞微丝骨架的标记

用农杆菌介导法将嵌合基因GFP-mTn(mTn是微丝结合蛋白Talin的微丝结合域,可以显示活体细胞中微丝的结构)导入蓝猪耳.经激光共聚焦显微镜观察了转基因植株的各种不同组织中融合蛋白的表达和分布情况.在叶片的表皮细胞、保卫细胞、根部的皮层细胞中有融合蛋白的不同程度表达.但仅在保卫细胞中微丝标记状况良好,显示基因表达的组织特异性.经光诱导处于开放态的气孔的保卫细胞微丝呈网状结构,在细胞内无规则分布;经黑暗诱导处于关闭态的气孔保卫细胞中微丝束沿保卫细胞纵轴排列,呈卷曲状分布,并观察到螺旋和环状的微丝结构.在转基因植株的其他部位,例如茎表皮细胞、根毛细胞和花粉粒中,未检测到目的基因的表达.本研究获得的转基因植株为研究气孔运动过程中微丝动态变化提供了有用的材料.     

4种作物部分非叶器官气孔频度及其在光合作用中的意义（英文

 通过对小麦（Triticum aestivum L.）、大豆 (Glycine max (L.) Merrill)、 油菜（Brassica napus L.）和玉米（Zea mays L.）等4种作物部分非叶器官(油菜和大豆的豆荚;小麦的外稃和玉米的苞叶)的气孔频度、气孔大小和气孔指数进行了比较研究。结果发现,上述作物非叶器官的气孔频度均较对应叶低;而气孔大小和气孔指数则变化较大。其中油菜和大豆非叶器官气孔的直径通常比对应叶大,小麦和玉米非叶器官的气孔直径则较小;大豆和油菜的非叶器官气孔指数比对应叶小,     

EXISTENCE OF TWO STOMATAL SHAPES IN THE GENUS DENDROBIUM (ORCHIDACEAE) AND ITS SYSTEMATIC SIGNIFICANCE

On the basis of the shape and size of the outer stomatal ledge, 153 species of the genus Dendrobium (Orchidaceae) were divided into three groups, i.e., species group I, species group II, and section Grastidium. Student's t-test and principal components analysis using seven stomatal characters suggest that the first two groups are quite distinct from each other. The values for section Grastidium, however, are scattered and indicative of heterogeneity. Our data suggest a high probability that species groups I and II are monophyletic sister groups. However, section Grastidium, in which stomatal diversification has occurred, may be para- or polyphyletic relative to the genus Dendrobium.