Guard Cells Of Stomata Research Articles

Chloroplast alterations in albino plants obtained from in vitro culture

Abstract Regenerated plants of Lycopersicon esculentum var. Alice were obtained from in vitro culture of cotyledons. Some of them showed different grades of leaf variegation, but a few plants were completely white. Here the chloroplasts of the mesophyll cells had completely failed to differentiate and contained no thylakoids. On the contrary those of the epidermal and stomata guard cells were normally developed. This suggests that in the albino plants a mutation had occurred in the submarginal initial cell responsible for mesophyll formation.

Effect Of Sodium Hexanitrocobaltate (III) Decomposition On Its Staining Of Intracellular Potassium Ions

The effect was examined of the chemical decomposition of the potassium stain sodium hexanitrocobaltate (III) (SHC), on its ability to produce stain granules of consistent size that could be used to estimate the K+ contents of stomatal guard cells. Stomata in detached epidermis from leaves of Vicia faba (fava bean) were stimulated to accumulate K+ by treating them with fusicoccin. Stomatal apertures and the fraction of guard cell area covered by K+ precipitate granules (K+ score) were measured by digitizing photographic enlargements, and K+ scores were correlated with the age of stain that had been stored either in open or closed containers. The ability of stain aged in open containers to produce consistent fractional cell coverage was compared to 1) the ability of identically treated stain to precipitate K+ from solutions of KCI, and to 2) the kinetics of decomposition of SHC. It was found that the fractional coverage of guard cells of stomata opened to the same apertures decreased with a first order rate constant of 2.3 x 10(-5)/sec. The mass of precipitate formed by treatment of KCl solutions was unchanged for 2 hr after initial preparation of the SHC, and decreased thereafter with a first order rate constant of 1.0 x 10(-5)/sec. When stored in tightly sealed containers, nearly 100 hr were required for an occasionally opened bottle of SHC to decay to the same efficacy as a solution left open to the air for 8 hr.

Phenotypic and genotypic characterization of an amylose-free starch mutant of the potato

The amylose-free (amf) potato mutant 86.040 has been characterized phenotypically and genotypically. Not only storage starch in tubers and metabolic starch in leaves but also starch in cells with specific functions, such as columella cells in the root cap and guard cells of stomata, was amylose-free. Doubled amf-clones of 86.040 flowered well, but the percentage of stainable pollen was low (8.2%). Therefore, they were used as female parent in crosses with diploid amylose-containing plants. Over 400 pollinations gave 13 berries, all dropping off prematurely; they contained 78 ovules with embryos at different developmental stages. Twenty F1 plants were obtained by embryo rescue, all having amylose starch. Three of them were characterized more extensively. They flowered well and pollen stainabilitity as well as seed set were high. Analysis of the F1 plants and of F1 × F1 progeny plants showed that the amf-character is monogenic and recessive. The locus involved was designated amf +and the mutated allele amf.

Cell volume ratios of natural and of induced tetraploid and diploid flowering plants.

Many volume ratios between tetraploid and diploid guard cells of stomata and between diploid and haploid pollen grains were compiled from the literature and from own unpublished results. The sources of possible errors are discussed. No difference was found between induced auto- and allotetraploids. Some of the ratios with tetraploids of the C0 generation, but less so of later generations, were extremely high. The medians of the ratios were highest in the C0 generation (pollen grains 2.0-2.1, guard cells 2.4) and smaller in later generations (pollen grains 1.9, guard cells 2.1). The ratios of tetraploids from nature were 1.5-1.8 and thus significantly smaller than 2. The reduction may be a result of a selection for cell size during evolution, or of a physiological self-adjustment.The length/width ratios of guard cells were on average greater, but those of anisodiametric pollen grains smaller in induced tetraploids than in diploids, with a broad range of variation. The finding for guard cells is at variance with a widely held opinion.

Myrosin cells and dilated cisternae of the endoplasmic reticulum in the order Capparales

Ultrastructural results for different types of protein–rich cells in five families generally accepted as Capparalean (Brassicaceae, Capparaceae, Resedaceae, Tovariaceae and Moringaceae) and two others (Gyrostemonaceae and Bataceae) considered by some workers to be Capparalean, support their alignment in the order Capparales. The term myrosin cell is used for those protein–rich cells which are typically idio–blastic and characterized by a homogenous, granular proteinaceous material in the vacuole and a cytoplasm which is filled with an extensive rough endoplasmic reticulum. This idioblastic myrosin cell type is characteristic for the Brassicaceae, Capparaceae, Tovariaceae, Moringaceae and Gyrostemonaceae. The guard cells of stomata may appear as myrosin cells, in which case they are termed guard–cell myrosin cells; they are found in the Resedaceae, Tovariaceae and Bataceae. Other proteinaceous cells are those with protein–rich dilated cisternae (DC) of the endoplasmic reticulum (ER). One type is the organelle–like DC, utricular or irregular dilations of the ER, filled with protein and ribosome–studded. Utricular DC are characteristic for the Brassicaceae and Capparaceae. Another type of DC is represented by protein–containing vacuoles derived from the ER, protein–rich ER–dependent vacuoles; these are found in the Brassicaceae, Capparaceae, Resedaceae, Tovariaceae and Gyrostemonaceae. The myrosin cells and cells with protein–rich dilated cisternae are here regarded as taxonomic criteria for the order Capparales.

Sequence of Events in the Digestion of Fresh Legume Leaves by Rumen Bacteria

When fresh whole leaves of six different species of forage legumes were suspended in an artificial rumen medium and inoculated with rumen bacteria, bacterial adhesion and proliferation were noted at the stomata, and penetration of the stomate by these bacteria was documented by electron microscopy. The invading bacteria adhered to surfaces within the intercellular space of the leaf and produced very extensive exopolysaccharide-enclosed microcolonies. After some of the legume leaf cell walls were disorganized and ruptured by bacterial digestion, these cells (notably, parenchyma and epidermal cells) were invaded by bacteria, with subsequent formation of intracellular microcolonies. However, other cells were neither ruptured nor colonized (notably, stomata guard cells and vascular tissue). At all stages of the digestion of intact legume leaves, the rumen bacteria grew in microcolonies composed of cells of single or mixed morphological types, and a particular ecological niche was often completely and consistently occupied by a very large microcolony of cells of single or mixed morphological types.

Role of Potassium in Stomatal Opening in the Leaf of Vicia faba

With isolated epidermal strips of Vicia faba, the intensity of potassium-staining in the guard cells of stomata was calibrated against the uptake of radioactively labeled potassium. By using this calibration, the quantity of potassium that had accumulated in the guard cells, as stomata of leaves of Vicia open in the light, was estimated. Results support the hypothesis that in leaves, as well as in isolated epidermal strips, potassium and an accompanying anion comprise the major, osmotically active solutes in the guard cells of open stomata.

Silica in Developing Epidermal Cells of Avena Internodes: Electron Microprobe Analysis

Silica is present in significant amount in mature guard and subsidiary cells of stomata, in trichomes and silica cells, and in the walls of long eidermal cells of Avena. No silica was detectable in cork cells of cork-silica cell pairs. Silica must be accumulated in these specialized epidermal cells quite rapidly.

Development of stomata and foliar structure of some Magnoliaceae

SUMMARY The development of stomata and other interesting anatomical features of leaves, sheathing stipules and perianth lobes of 5 species of Magnolia and 4 species of Michelia were studied. Very often the mature foliar stomata are paracytic with 2 parallel subsidiaries and 1 or more parallel encircling cells but the stomata in the sheathing stipules and perianth lobes are usually anomocytic. A fairly constant feature of the foliar stomata of these plants is the partial overlapping of the subsidiary cells by the guard cells. Epidermal cells of a few species contain calcium oxalate druses. In Magnolia grandiflora and M. pumila the epidermal cells possess peculiar rod-shaped bodies of uncertain chemical nature. Polygonal or lobed thick walled brachysclereids occur singly or in groups in the various investigated species. Thin walled vesiculose sclereids are found in the leaves of all plants but they are absent in other organs of some species. The 2 parallel subsidiary cells and encircling cells of stomata develop from the same initial. The development of stomata is, therefore, typically mesogenous (syndetocheilic). According to Rao (1939) the encircling cells in some of these plants are formed by divisions of the subsidiary cells and although this is partly true the encircling cells of a majority of stomata are formed directly from the stomatal meristemoids. According to Paliwal & Bhandari (1962) the anomocytic stomata of the perianth lobes of Magnolia grandiflora, M. stellata and Michelia champaca are haplocheilic which implies that they are perigenous. However, we find that the irregular ring of cells around the guard cells of stomata in these parts and in the sheathing stipules, develop as a result of divisions in the mesogene subsidiary cells indicating thereby that these stomata are mesogenous and their development is essentially similar to that of foliar stomata.

The Size of Guard Cells of Stomata of a Natural Polyploid Series of the GenusTriticum L.

1. Byla studována délka svěracích buněk průduchů a počet průduchů na plošnou jednotku u 20 odrůd deseti různých druhů polyploidní řady roduTriticum, L. na otiscích nejvyššího listu, zhotovených acetonovým lakem. 2. Délka průduchů stoupá se vzrůstajícím počtem chromosomů (diploidníT. monococcum L. 33,4μ, tetraploidní druhy mimoT. timopheevi ZHUK. 42,0μ, hexaploidní druhy 45,4μ). Odlišnou velikost průduchů máT. timopheevi ZHUK. (48,1μ). Je to další důkaz oddělenosti tohoto druhu od ostatních tetraploidních pšenic. Uvnitř jednotlivých skupin o stejném počtu chromosomů mají větší délku svěracích buněk druhy fylogeneticky pokročilejší. ?? je snad možno spojovat s celkovou mesofylisací rodu v průběhu fylogenese. Nelze ovšem zanedbávat ekologické vlivy. 3. Podle působení na délku průduchů u jednotlivých skupin lze jednotlivé genomy seřadit do této sestupné řady: A > G > B > D. 4. Počet průduchů na plošnou jednotku nejeví žádnou souvislost s počtem chromosomů. Na počet průduchů mají zřejmě vliv více ekologické faktory než vnitřní vztahy genetické.

Studies on mint breeding : X. Induced triploid clor of Japanese mint (Mentha arvensis L. var. piperascens MAL.).

This investigation was undertaken to see the morphological, physiological and cytological characters of triploid clone of the Japanese mint and also to study its economic values. In 1905 and 1956, 35 triploid clones (3n, somatic number=144:) of the Japanese mint were raised by the crossings of induced tetraploid clones (4n=192) with diploid clones (2n=96). The inverse crossings, however, did not succeed because of the failure of germination of the seeds obtained by crossings. Hence the triploid clone has not yet been obtained by 2nx4n. As the basic number of chromosomes in the genus lklelctho is twelve, strictly mosomes in the genus lklelctho is twelve, strictly speaking the Japanese mint, its triploid and tetraploid clone, should be called octaploid, dodekaploid and hexadekaploid clone, respecfively. However, for convenience' sake, the authors will name them respectively, diploid, triploid and tetraploid clone of the Japanese mint as mentioned above, in this paper. The triploid plants grow well and are somewhat larger than 2n plants in the vegetativc orgnns. Leaves are ovatc-oblong, not so broad as the ovate leaves of 4n plants, but broader than the lanceolate leaves of 2n plants. Guard cells of stomata, hairs and essential oil glands of 3n plants, which are all observed on the epidermis of their leaves, become larger or longer than those of 2n plants, but are not so large or long as those of 4n plants. On the contrary, their numbers in the unit area of leaves are reduced as compared with those in 2n plants, though not so much reduced as those in 4n plants. Flowers come into bloom from July to September in Okayama district. Early clones are as early as 2n ones and late clones are as late as 4n ones. Anthers become atrophied and no fertile pollen is found in the pollensac in any of 3n clones. Seeds set ncither in open pollination nor in back cross to parents. In 1957 about 1800 flowers were tested and only three seeds were obtained. It is presumable that fertility is nearly zero in the female gametic organ as in the male gametic one.

シダ類の配偶体に関する細胞学的ならびに形態学的研究 XII

Surveying the suction forces of the wall cells, viz. the cap cell, the ring cell, and the basal ring cell of the antheridium and the suction force of the spermatid chiefly in Leptogramma totta J. Smith, the following facts were obtained.1. The suction force of the wall cell is comparatively high and is equivalent to the osmotic value of 0.98M aqueous solution of sucrose which corresponds to 33.6 atmospheres.2. This value is higher than that of the seashore plant cell known as possessing a high osmotic value. Concerning the magnitude of the osmotic value, the relationship between the wall cells and the prothallial cells resembles the relationship between the guard cells of stomata and the epidermal cells.3. The suction force of the spermatid is also comparatively high and corresponds to the osmotic value of 0.74M aqueous solution of sucrose (23.1) atmospheres.4. The mechanism shown by the wall cell and the spermatid having a high suction force is considered to be an important factor in the dehiscence of the antheridium and the extrusion of the spermatozoid out of the spermatid.

ÉTUDES SUR LE GENRE SOLIDAGO L. : II. LA MISE EN ÉVIDENCE DE LA POLYPLOÏDIE ENDOTAXONIQUE CHEZ S. PURSHII PORTER ET LES TAXA SIMILAIRES

In Solidago Purshii Porter, there are two cytodemes, one diploid (2n = 18) and the other tetraploid (2n = 36), which can be distinguished on the basis of the length of the guard cells of their leaf stomata. The diploid plants possess guard cells which are smaller than those of the tetraploid. These two entities of S. Purshii thus belong to the groups of cytodemes in which there exists a positive correlation between the chromosome numbers and the dimensions of certain quantitative morphological characters, such as the length of the guard cells.In groups in which the variation curves of the characters of the different cytodemes overlap little or not, the geographical distribution of the different cytodemes of the complex may be studied much more easily, rapidly, and comprehensively by measuring the length of the guard cells of herbarium specimens than by making chromosome number determinations. The data presented indicate that when sampling is made under the conditions described in this paper, determinations of the length of two guard cells of stomata of one mid-leaf per individual, made on two individuals per colony, is satisfactory for that purpose, on the average. However, it is recommended, as a safeguard, to increase these figures by a few units, and to make always a few direct chromosome number determinations to check the accuracy of this rapid technique. These direct determinations may also be necessary to know the chromosome numbers of certain extreme individuals of the different cytodemes which have guard cells that differ little in length.

Cytogenetical studies on the amphidiploid of Quamoclit

Cytogenetical studies on the amphidiploids raised from interspecific hybrids of Quamoclit by the colchicine treatment have been carried out by the author.In amphidiploids, the length of guard cells of stomata is larger than that of the parents, and about as large as that of Q. Sloteri (Table 3).Further, the size of flowers is larger than that of the parents (Fig. 2).In F1 plants, abortive pollen grains were observed in exceedingly higher percentage than in amphidiploids (Table 5). The size of pollen grains in amphidiploids is larger than that of the F1 (Table 6), i. e., nearly equal in size to the Q. Sloteri's.F1 plants were completely sterile, but the amphidiploids were fertile, though the percentage is low (16.04%).The fruits of amphidiploids were morphologically intermediate between parents of them.The weight of 1000 seeds of Q. coccinea, Q, coccinea var. hederifolia and Q. pennata were 11.6, 14.2 and 16.5grs respectively. And that of the amphidiploids from hybrid I and II were 30.1 and 32.6grs, that is nearly equal to the seed weight of Q. Sloteri, 31.6grs.The number of somatic chromosomes were 30 in Q. pennata (Fig. 7). 28 in both Q. coccinea and Q. coccinea var. hederifolia (Figs. 5 and 6). In F1 plants of Q. coccinea×Q. pennata and Q. coccinea var. hederifolia×Q. pennata, the number of chromosomes was 2n=29 (Figs. 8 and 9) in both cases. The number of chromosomes of amphidiploids raised from hybrid I (Q. coccinea×Q. pennata) and II (Q. coccinea var. hederifolia×Q. pennata) was 2n=58 in both combinations (Fig. 10). These numbers correspond to double the somatic number of F1 of hybrids I and II, viz. equal to the number of Q. Sloteri's chromosomes 2n=58 (Fig. 11).