Branching patterns in Trichomanes and Cardiomanes (hymenophyllaceous ferns)

1984 ◽  
Vol 62 (7) ◽  
pp. 1336-1343 ◽  
Author(s):  
R. Hébant-Mauri
Keyword(s):  
Apical Meristem ◽  
Apical Cell ◽  
Relative Orientation ◽  
Vertical Position ◽  
Leaf Base ◽  
Lateral Organs ◽  
Branching Patterns ◽  
Initiation Stage ◽  
Accurate Observation ◽  
Leaf Insertion

Previous observations on Trichomanes with thick stems and axillary buds are compared with those recently obtained from species with slender stems and extraaxillary buds and also from Cardiomanes. In all species, leaves arise from typical two-sided apical cells and buds are initiated adjacent to them in cauline tissues, laterally on the apical meristem. Three different localizations of buds occur (axillary, extraaxillary, and intermediate) and result in different orientations of the whole lateral system (= leaf + bud). Each different arrangement is visible as early as the initiation stage. The leaf apical cell faces the bud initials in all cases. Growth does not interfere with relative orientation of the organs but greatly changes the vertical position of the buds, which may be borne on the stem near leaf insertion or at the leaf base. These results illustrate the necessity of accurate observation of the ontogenetic origin of lateral organs to define them.

scholarly journals Towards an understanding of spiral patterning in the Sargassum muticum shoot apex

2017 ◽  
Author(s):  
Marina Linardić ◽  
Siobhan A. Braybrook
Keyword(s):  
Cell Division ◽  
Brown Alga ◽  
Apical Meristem ◽  
Apical Cell ◽  
The Body ◽  
Sargassum Muticum ◽  
Control Mechanisms ◽  
Lateral Organs ◽  
Division Pattern ◽  
Underlying Mechanisms

AbstractIn plants and parenchymatous brown algae the body arises through the activity of an apical meristem (a niche of cells or a single cell). The meristem produces lateral organs in specific patterns, referred to as phyllotaxis. In plants, two different control mechanisms have been proposed – one is position-dependent and relies on morphogen accumulation at future organ sites whereas the other is a lineage-based system which links phyllotaxis to the apical cell division pattern. Here we examine the apical patterning of the brown alga, Sargassum muticum, which exhibits spiral phyllotaxis (137.5° angle) and an unlinked apical cell division pattern. The Sargassum apex presents characteristics of a self-organising system, similar to plant meristems. We were unable to correlate the plant morphogen auxin with bud positioning in Sargassum, nor could we predict cell wall softening at new bud sites. Our data suggests that in Sargassum muticum there is no connection between phyllotaxis and the apical cell division pattern indicating a position-dependent patterning mechanism may be in place. The underlying mechanisms behind the phyllotactic patterning appear to be distinct from those seen in plants.SummaryThe brown alga Sargassum muticum displays spiral phyllotaxis developed from a position-dependent self-organising mechanism, different from that understood in plants.

scholarly journals Meristem Development and its Relation to Endogenous GA3 and IAA Contents During Floral Bud Differentiation in Broccoli

2011 ◽  
Vol 35 (1) ◽  
pp. 1-6
Author(s):  
Xinmei Jiang ◽  
Xihong Yu ◽  
Dan Li
Keyword(s):  
Apical Meristem ◽  
Morphological Changes ◽  
Flower Bud ◽  
Bud Development ◽  
Meristem Development ◽  
Early Maturing ◽  
Initiation Stage ◽  
Academy Of Sciences ◽  
Bud Initiation ◽  
Floral Bud

The effects of three temperature treatments on morphological changes in the apical meristem and contents of GA3 and IAA in leaves during floral bud differentiation in early maturing cultivar of broccoli were studied. Plants went through every stage of flower-bud differentiation at day/night temperatures of 17.3±1/9.3±1°C. At 21.3±1/13.3±1°C, floral bud development ceased after primary axillary scape primordium differentiation and apical meristem entered a reversion stage. The apical meristem remained in the vegetative growth phase in plants growing at 25.3±1/17.3±1°C. Leaf GA3 contents started to increase while IAA contents started to decrease when plants entered the flower bud initiation stage. GA3 content was high and IAA content was low during all stages of axillary scape primordium differentiation.Key words: Meristem development; Broccoli; Apical meristem; GA3; IAADOI: http://dx.doi.org/10.3329/jbas.v35i1.7966 Journal of Bangladesh Academy of Sciences, Vol.35, No.1, 1-6, 2011

scholarly journals Feedback from Lateral Organs Controls Shoot Apical Meristem Growth by Modulating Auxin Transport

2018 ◽  
Vol 44 (2) ◽  
pp. 204-216.e6 ◽  
Author(s):  
Bihai Shi ◽  
Xiaolu Guo ◽  
Ying Wang ◽  
Yuanyuan Xiong ◽  
Jin Wang ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Auxin Transport ◽  
Lateral Organs

Interplay between the shoot apical meristem and lateral organs

aBIOTECH ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 178-184
Author(s):  
Chunmei Guan ◽  
Yuling Jiao
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Lateral Organs

scholarly journals Diversity of phyllotaxis in land plants in reference to the shoot apical meristem structure

2016 ◽  
Vol 85 (4) ◽  
Author(s):  
Edyta M. Gola ◽  
Alicja Banasiak
Keyword(s):  
Pattern Formation ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Land Plants ◽  
Phyllotactic Pattern ◽  
Lateral Organs ◽  
Spatio Temporal

Regularity and periodicity in the arrangements of organs in all groups of land plants raise questions about the mechanisms underlying phyllotactic pattern formation. The initiation of the lateral organs (leaves, flowers, etc.), and thus, their spatio-temporal positioning, occurs in the shoot apical meristem (SAM) and is related to the structure and organogenic activity of the meristem. In this review, we present some aspects of the diversity and stability of phyllotactic patterns in the major lineages of land plants, from bryophytes to angiosperms, in which SAM structures differ significantly. In addition, we discuss some of the possible mechanisms involved in the formation of the recurring arrangement of the lateral organs.

Members of the YABBY gene family specify abaxial cell fate in Arabidopsis

Development ◽  
1999 ◽  
Vol 126 (18) ◽  
pp. 4117-4128 ◽  
Author(s):  
K.R. Siegfried ◽  
Y. Eshed ◽  
S.F. Baum ◽  
D. Otsuga ◽  
G.N. Drews ◽  
...  
Keyword(s):  
Gene Family ◽  
Cell Fate ◽  
Apical Meristem ◽  
Ectopic Expression ◽  
Cell Fates ◽  
Lateral Organs ◽  
Expression Studies ◽  
Lateral Organ ◽  
Yabby Gene ◽  
Filamentous Flower

Lateral organs produced by shoot apical and flower meristems exhibit a fundamental abaxial-adaxial asymmetry. We describe three members of the YABBY gene family, FILAMENTOUS FLOWER, YABBY2 and YABBY3, isolated on the basis of homology to CRABS CLAW. Each of these genes is expressed in a polar manner in all lateral organ primordia produced from the apical and flower meristems. The expression of these genes is precisely correlated with abaxial cell fate in mutants in which abaxial cell fates are found ectopically, reduced or eliminated. Ectopic expression of either FILAMENTOUS FLOWER or YABBY3 is sufficient to specify the development of ectopic abaxial tissues in lateral organs. Conversely, loss of polar expression of these two genes results in a loss of polar differentiation of tissues in lateral organs. Taken together, these observations indicate that members of this gene family are responsible for the specification of abaxial cell fate in lateral organs of Arabidopsis. Furthermore, ectopic expression studies suggest that ubiquitous abaxial cell fate and maintenance of a functional apical meristem are incompatible.

Predetermination of lateral shoot characteristics in grand fir

1984 ◽  
Vol 62 (6) ◽  
pp. 1309-1315
Author(s):  
John Worrall
Keyword(s):  
Apical Meristem ◽  
Compensatory Growth ◽  
Growing Season ◽  
Light Interception ◽  
Internode Length ◽  
Vertical Position ◽  
Lateral Shoot ◽  
Terminal Bud ◽  
Number Of Leaves

The terminal bud and all but one subterminal bud were removed from the terminal leaders of shade-grown 15-year-old grand fir plants at monthly intervals during the season of their formation. The growth of shoots from the remaining subterminal bud was assessed in August of the following growing season and compared with control shoots. These latter displayed marked plagiotropy and distichy under the conditions of the experiment. In treated plants, compensatory growth occurred, with respect to both number of leaves and internode length. The shoots assumed a more vertical position, earlier treatment being more effective. The distichous positioning of leaves on these shoots, however, was not affected, causing leaves to be oriented in a manner inefficient for light interception. Plagiotropy seemed to have been imposed on the shoot gradually, during the season prior to its growth, whereas distichy was perhaps imposed close to the time of inception of the shoot's apical meristem. Possible reasons for this are discussed.

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