Differentiation of stomatal meristemoids and guard cell mother cells into guard-like cells in Vigna sinensis leaves after colchicine treatment

B. Galatis

doi:10.1007/bf00396185

The organization of microtubules in guard cell mother cells of Zea mays

Canadian Journal of Botany ◽

10.1139/b82-145 ◽

1982 ◽

Vol 60 (7) ◽

pp. 1148-1166 ◽

Cited By ~ 50

Author(s):

B. Galatis

Keyword(s):

Zea Mays ◽

Nuclear Envelope ◽

Guard Cell ◽

Cortical Microtubule ◽

Colchicine Treatment ◽

Early Prophase ◽

Cortical Regions ◽

Periclinal Walls ◽

Mother Cells ◽

Dictyosome Vesicles

The cortical interphase microtubules of the guard cell mother cells (GMCs) of Zea mays form a well-grouped band (interphase microtubule band, IMB) lining the midregion of the lateral and periclinal walls, which are the only expanding walls during interphase. In advanced interphase GMCs, another population of microtubules emerge from the cortical cytoplasm of the midregion of the periclinal walls, entering deep into the cytoplasm. Elongated proplastids converge on the above cortical regions, possibly aligned by the microtubules with which they are associated.The IMB depolymerizes prior to mitosis and a preprophase microtubule band (PMB) is organized adjacent to the proximal, distal, and periclinal walls. In transverse sections the preprophase – early prophase nucleus appears slightly elliptical or spindle-shaped, sometimes exhibiting acute angular profiles at its poles. Extranuclear microtubules closely juxtaposed with the nuclear envelope converge on the "poles" of the nucleus, close to the regions of the PMB adjacent to the periclinal walls. The observations suggest a local interplay between the PMB and (or) the PMB cytoplasmic site on the one hand and the nuclear envelope and (or) the extranuclear microtubules on the other.The microtubules of both bands lining the periclinal walls and the sites of their junctions with the anticlinal ones are more closely grouped than those running along the anticlinal walls, and they exhibit intimate associations with numerous dictyosome vesicles. This preferential gathering of dictyosome vesicles, among others, possibly manifests a mechanism promoting the thickening of the expanding regions of the above walls.The inhibition of the symmetrical divisions of the GMCs by a continuous colchicine treatment leads to the formation of epidermal idioblasts possessing some of the characteristidcs of the guard cells. Furthermore, in the absence of microtubules, local wall thickenings are deposited in the middle of the periclinal walls and at their junctions with the anticlinal ones.From the observations it seems likely that guard cell differentiation commences in GMC, and that the cortical cytoplasm and (or) the plasmalemma of the midregion and the edges of the periclinal walls of the GMC possess some factor(s) favouring their preferential thickening. Cortical microtubule organizing centres (MTOCs) appear to be localized in these regions and activated in a programmed fashion.

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Molecular cytogenetic analysis of wheat-alien hybrids and derivatives

Acta Agronomica Hungarica ◽

10.1556/aagr.50.2002.3.8 ◽

2002 ◽

Vol 50 (3) ◽

pp. 303-311 ◽

Cited By ~ 8

Author(s):

M. Molnár-Láng ◽

G Linc ◽

E. D. Nagy ◽

Keyword(s):

Ssr Markers ◽

Molecular Genetic ◽

Colchicine Treatment ◽

Translocation Chromosome ◽

Chromosome Polymorphism ◽

Translocation Breakpoints ◽

Mother Cells ◽

High Degree

New wheat × barley, wheat × Aegilops biuncialis and wheat × rye hybrids were produced with the aim of alien gene transfer from these species into wheat. Amphiploids were produced with the help of colchicine treatment from the last two combinations. The new wheat × barley hybrids were multiplied in tissue culture because of the high degree of sterility and then pollinated with wheat to obtain backcross progenies. Wheat-barley chromosome pairing was detected using genomic in situ hybridization (GISH) in two combinations (Mv9 kr1 × Igri, Asakazekomugi × Manas). In vitro conditions caused an increase in chromosome arm association frequency in both combinations and in fertility in some regenerants. Five wheat-barley translocations were produced in a wheat background and characterized through the combination of cytogenetic and molecular genetic approaches (GISH, FISH and SSR markers). The following translocations were identified: 2DS.2DL-1HS, 3HS.3BL, 6BS.6BL-4HL, 4D-5HS and 7DL.7DS-5HS. Physical mapping of the SSR markers on chromosomes 1H and 5H was carried out using the intragenomic and interspecific translocation breakpoints and the centromere as physical landmarks. Disomic wheat-Aegilops biuncialis additions were produced after backcrossing the wheat-Ae. biuncialis amphiploids. Fluorescence in situ hybridization (FISH) was carried out using two repetitive DNA clones (pSc119.2 and pAs1) on Ae. biuncialis and its two diploid progenitor species to detect chromosome polymorphism. The 7M and 3M disomic chromosome additions were selected and five more lines still need to be characterized. The octoploid triticale (Mv9 kr1 × Lovászpatonai) produced in Martonvásár was crossed with a 1RS.1BL wheat cultivar Matador. GISH analysis detected pairing between the 1RS arm of the translocation chromosome and that of Lovászpatonai rye in 32 % of the pollen mother cells, making it possible to select recombinants from this combination. The new recombinants between the 1RS of Petkus and the 1RS of Lovászpatonai rye cultivars are being analysed with the help of microsatellite markers.

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Studies on the formation of ‘floating’ guard cell mother cells in Anemia

Journal of Cell Science ◽

10.1242/jcs.80.1.29 ◽

1986 ◽

Vol 80 (1) ◽

pp. 29-55

Author(s):

B. Galatis ◽

P. Apostolakos ◽

D. Palafoutas

Keyword(s):

Guard Cell ◽

Intercellular Space ◽

Cortical Microtubule ◽

Cell Plate ◽

Cell Polarization ◽

Periclinal Wall ◽

Wall Area ◽

Cortical Zone ◽

Neighbouring Region ◽

Mother Cells

The protodermal cells producing the ‘floating’ guard cell mother cells (GMCs) in three Anemia species undergo an extraordinary polarization and an unexpected shaping. During interphase an intercellular space is initiated at the internal proximal end of the cell, while the polar region bulges outwards. At this stage a microtubule girdle traverses the cortical cytoplasm underneath the rims of the external periclinal wall curvature. In addition, another system of microtubules converges on a cortical site adjoining the wall delimiting the intercellular space and, or, the neighbouring region of the internal periclinal wall (internal polar cortical site, IPCS). Vacuoles are found in all regions of the cell except for that between the centrally located nucleus and the intercellular space. As the cell approaches mitosis, the growing vacuolar system retreats from the cytoplasmic region below the external periclinal wall curvature. In most cells the polarized cytoplasm forms an inclined truncated cone, the bases of which abut on the external periclinal wall curvature and the wall lining the IPCS. The organization of the cortical microtubule cytoskeleton does not change significantly during preprophase-prophase. A preprophase microtubule band (PMB) is localized in the cortex lining the rims of the external periclinal wall curvature, while some microtubules traverse the IPCS and the cytoplasm adjacent to the neighbouring wall regions. The mitotic spindle axis is diagonal, while the cell plate separating the GMCs exhibits an unusual mode of growth. It gradually encircles the proximal daughter nucleus, becoming funnel-shaped. One of its periclinal edges fuses with the external periclinal wall area lined by the PMB cortical zone and the other with the internal periclinal wall area adjoining the IPCS. The latter region seems to behave like the PMB cortical zone. The results show that the morphogenetic mechanism underlying the formation of the conical GMCs includes a series of highly integrated processes, initiated or carried out during cell polarization.

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On the differential divisions and preprophase microtubule bands involved in the development of stomata of Vigna sinensis L

Journal of Cell Science ◽

10.1242/jcs.37.1.11 ◽

1979 ◽

Vol 37 (1) ◽

pp. 11-37

Author(s):

B. Galatis ◽

K. Mitrakos

Keyword(s):

Cell Polarity ◽

Cell Plate ◽

Equatorial Position ◽

Anticlinal Wall ◽

Vigna Sinensis ◽

Daughter Cells ◽

Preprophase Microtubule Band ◽

Dicotyledonous Plants ◽

Mother Cells ◽

Dictyosome Vesicles

The manifestation of premitotic cell polarity and the resultant structural asymmetry of the differential divisions participating in the development of stomata of Vigna sinensis vary considerably. However, two morphologically distinct types of differential division were distinguished: (a) ‘asymmetrical differential divisions’, in which the premitotic polarization of the cell, the eccentric position of the nucleus during division and the differences in size and organization of the daughter cells are obvious; and (b) differential divisions in which the above features are inconspicuous or almost absent. The former occur in the ordinary protodermal cells, the latter in some meristemoids. The organization of a sharply demarcated preprophase microtubule band (PMB) precedes, all differential and non-differential divisions. In the first type of differential division the PMB is formed eccentrically, while in the second it may display either an approximately symmetrical or a clearly asymmetrical disposition, always indicating with surprising accuracy the sites where the succeeding cell plate will join the parent walls. The PMB foreshadowing the highly curved cell plates in meristemoids I of the mesoperigenous process, as well as in meristemoids I and II of the mesogenous one, are apposed only on one anticlinal wall and therefore do not encircle the nucleus or traverse the cell. In the symmetrical divisions of guard cell mother cells (GMC), as well as in those of protodermal cells, the PMB runs right round the internal plasmalemma surface in an equatorial position, coinciding with that of the future cell plate. In the former cells the wall abutting the cortical cytoplasm traversed by the band becomes locally thickened. The variability in the pattern of the microtubules of the band along the walls of the GMC is directly mirrored in the pattern of the thickening. It seems that in GMC the PMB mediates a directed exocytosis of dictyosome vesicles. In contrast to what is now generally accepted in dicotyledonous plants, each meristemoid I of both the mesogenous and mesoperigenous stomata in Vigna sinensis leaves does not inhibit but induces the formation of other meristemoids close to it.

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Pre-prophase Microtubule Band and Local Wall Thickening in Guard Cell Mother Cells of Some Leguminosae

Annals of Botany ◽

10.1093/oxfordjournals.aob.a086422 ◽

1982 ◽

Vol 50 (6) ◽

pp. 779-791 ◽

Cited By ~ 33

Author(s):

B. GALATIS ◽

P. APOSTOLAKOS ◽

CHR. KATSAROS ◽

H. LOUKARI

Keyword(s):

Guard Cell ◽

Wall Thickening ◽

Mother Cells

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Microtubule Orientation During Stomatal Differentiation in Grasses

Journal of Cell Science ◽

10.1242/jcs.92.4.581 ◽

1989 ◽

Vol 92 (4) ◽

pp. 581-594

Author(s):

SOON-OK CHO ◽

SUSAN M. WICK

Keyword(s):

Hair Cell ◽

Hair Cells ◽

Guard Cell ◽

Mother Cell ◽

Early Stage ◽

Preprophase Band ◽

Subsidiary Cell ◽

Stomatal Complex ◽

Face View ◽

Mother Cells

The changing orientation of microtubules (MTs) during formation of the stomatal complex in grasses was observed by immunofluorescence microscopy, beginning with the asymmetrical division of the cell that gives rise to the guard cell mother cell, i.e. the guard cell grandmother cell. The asymmetrically placed preprophase band (PPB) of guard cell grandmother cells and hair cell mother cells is always laid down parallel to the distal end wall even when this wall is oblique to the long axis of the cell. The first step in formation of the PPB of a subsidiary cell mother cell appears to be establishment of an incomplete band of MTs. Whereas the mature PPB forms a curved line in a face view of a subsidiary cell mother cell, in this early stage MTs form fan-shaped arrays that focus on two points along the edge of the subsidiary cell mother cell. Replacement of the transversely oriented interphase microtubule band of the guard cell mother cell with the longitudinally oriented PPB involves several distinctive stages: (1) appearance of MTs directed toward the centre of the periclinal surface along the entire length of the lateral walls. (2) Appearance of another set of MTs along the entire width of both end walls, likewise focused toward the centre of the periclinal surface. Together these two groups of MTs form a cross with broadened tips in face view of the leaf. (3) Disappearance of the first set of MTs, and formation of an increasingly narrow band from the latter at the site of future cytokinesis. Although the anaphase spindles of guard cell grandmother cells, hair cell mother cells and guard cell mother cells are usually diagonally oriented relative to the site occupied previously by the PPB, the line connecting the centres of the spindle poles that are established at prophase is perpendicular to the persisting PPBs. Unlike the situation in certain other hair cells, MTs in leaf hair cells are transversely oriented even when the cells are highly elongated.

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