scholarly journals The Mitochondrial Cycle of Arabidopsis Shoot Apical Meristem and Leaf Primordium Meristematic Cells Is Defined by a Perinuclear Tentaculate/Cage-Like Mitochondrion

2008 ◽  
Vol 148 (3) ◽  
pp. 1380-1393 ◽  
Author(s):  
José M. Seguí-Simarro ◽  
María José Coronado ◽  
L. Andrew Staehelin
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Leaf Primordium ◽  
Meristematic Cells

Phyllotaxis of the palm Euterpe oleracea Mart. at the level of the shoot apical meristem

Botany ◽  
2010 ◽  
Vol 88 (5) ◽  
pp. 528-536 ◽  
Author(s):  
Denis Barabé ◽  
Laura Bourque ◽  
Xiaofeng Yin ◽  
Christian Lacroix
Keyword(s):  
Shoot Apical Meristem ◽  
Fundamental Theorem ◽  
Apical Meristem ◽  
Leaf Primordia ◽  
Leaf Primordium ◽  
Divergence Angle ◽  
Euterpe Oleracea ◽  
The Mean ◽  
The Relationship ◽  
Euterpe Oleracea Mart

Previous studies on palm phyllotaxis deal mainly with the mature trunk. The goals of this study are (i) to determine the relationship between the number of parastichies, the divergence angle, and the plastochrone ratio at the level of the shoot apical meristem; (ii) to examine whether there are fluctuations in the divergence angle; (iii) to interpret the significance of phyllotactic parameters with respect to the mode of growth of the apex. The tubular base of the leaf primordium is more or less asymmetrical, and completely surrounds the shoot apical meristem. The phyllotactic system corresponds to a (2, 3) conspicuous parastichy pair. The mean divergence angle per apex varies between 126.9° ± 9.3° (mean ± SD) and 135. 8° ± 8.0°. Divergence angles for all apices fluctuate within a range of 115.89° to 157.33°. The mean plastochrone ratios between apices varies from 1.35 ± 0.18 to 1.58 ± 0.12. The plastochrone ratio at each plastochrone for all apices ranges from 1.09 to 2.00. There is no correlation between the angle of divergence and the plastochrone ratio. There is a fluctuation in the value of the divergence angle that falls within the range predicted by the fundamental theorem of phyllotaxis. The high value of the ratio of the diameter of leaf primordia over the diameter of the apex, and the long plastochrone might explain the lack of correlation between certain phyllotactic parameters.

scholarly journals SHOOT ORGANIZATION Genes Regulate Shoot Apical Meristem Organization and the Pattern of Leaf Primordium Initiation in Rice

2000 ◽  
Vol 12 (11) ◽  
pp. 2161-2174 ◽  
Author(s):  
Jun-Ichi Itoh ◽  
Hidemi Kitano ◽  
Makoto Matsuoka ◽  
Yasuo Nagato
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Leaf Primordium

Does growth rate determine leaf form in Pisum sativum?

1989 ◽  
Vol 67 (9) ◽  
pp. 2590-2595 ◽  
Author(s):  
Kevin S. Gould ◽  
Elizabeth G. Cutter ◽  
J. Peter W. Young
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Vertical Displacement ◽  
Significant Rise ◽  
Leaf Primordium ◽  
Relative Growth ◽  
Leaf Extension ◽  
Mutant Pea

We have examined the long-standing hypothesis that leaves are morphologically more complex following prolonged proximity to the shoot apical meristem. Growth rates of the petiole and rachis of conventional and mutant pea leaves were compared for successive nodes of insertion in seedling plants. Leaves were longer at higher nodes, though the relative growth rate did not vary. Mature afila leaves were longer than those of conventional and tendril-less genotypes. The afila leaf alone exhibited a transient, highly significant rise in relative growth rate during the plastochron interval P4.5–P5.5. This rise occurred after the stage at which leaves of the different genotypes were anatomically distinguishable (stage P2–P3). Rates of vertical displacement of the leaf primordium from the shoot apical meristem did not differ significantly among genotypes. Our data suggest that the rate of leaf extension is one of the consequences, rather than a cause, of leaf morphology.

Les teneurs ioniques des plants d'Isoetes setacea au cours de la réactivation par réhydratation

1986 ◽  
Vol 64 (10) ◽  
pp. 2171-2177
Author(s):  
N. Michaux-Ferrière
Keyword(s):  
Water Stress ◽  
Drought Resistance ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Normal Growth ◽  
Active Metabolism ◽  
Meristematic Cells ◽  
Differentiated Cells ◽  
Whole Plant ◽  
Different Parts

Ionic amounts of S, P, K+, Ca2+, and Mg2+ have been determined by chemical measures in different parts of Isoetes setacea (shoot apical meristem, cortical zone, and central stele) for plants in normal growth, in drought resistance, and during rehydration. Study of modifications in the ionic amounts during experimental rehydration showed that the significant increase of K+, Ca2+, and Mg2+ by the 24th h of experimentation was one of the earliest signals observed for the cells of the apical meristem (which are at that time blocked in G1 presynthesis phase) as well as for the differentiated cells. By the 7th day of rehydration, just before their entrance into the synthesis phase, meristematic cells have recovered ionic rates equivalent to those measured for active plants. The same thing happens in the nonmeristematic tissues. This increase of ionic amounts in the whole plant can be explained by a differential entrance of ions with water. This new balance of the ionic amounts according to the pattern found in the active plants can be considered as a prerequisite event for the recovery of an active metabolism for a meristematic or differentiated cell in water stress.

SHOOT ORGANIZATION Genes Regulate Shoot Apical Meristem Organization and the Pattern of Leaf Primordium Initiation in Rice

2000 ◽  
Vol 12 (11) ◽  
pp. 2161
Author(s):  
Jun-Ichi Itoh ◽  
Hidemi Kitano ◽  
Makoto Matsuoka ◽  
Yasuo Nagato
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Leaf Primordium

Developmental potentialities of leaf primordia of Osmunda cinnamomea. V. Toward greater understanding of the final morphogenetic expression of isolated set I cinnamon fern leaf primordia

1969 ◽  
Vol 47 (3) ◽  
pp. 481-488 ◽  
Author(s):  
Thomas H. Haight ◽  
Charles Carroll Kuehnert
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Leaf Primordia ◽  
Leaf Primordium ◽  
Bud Formation ◽  
State Bearing ◽  
Leaves And Roots

Arguments supported by the data given favor the interpretation that (1) adaxial buds are produced by Osmunda cinnamomea leaf primordia; (2) they are produced in addition to the leaf which bears them; (3) they are to be considered adventitious rather than axial; (4) they are of a strictly foliar rather than cauline nature; and (5) they are produced only when a primordium has been isolated from the rest of the shoot system.In O. cinnamomea, the bud, which is formed in addition to the leaf primordium, is evident at the end of the fifth to sixth week on singly cultured P3 and P4 leaf primordia. With younger leaf primordia, e.g. P2’s, often the only evidence of bud formation at the termination of an 8-week culturing period is the presence of the new apical meristem (the SAM′). In the case of older primordia, however, such as P4’s, whether cultured singly or isolated from the shoot apical meristem (SAM) on a plug of tissue, the bud is observed to consist of the SAM′, and from one to seven new leaf primordia. At this stage, the meristematic outgrowth can be considered to be in the true bud state. If the culturing period is extended beyond 8 weeks, the SAM′ develops from the bud state into the plantlet state bearing miniature juvenile leaves, and roots.

The SHOOTLESS2 and SHOOTLESS1 Genes Are Involved in Both Initiation and Maintenance of the Shoot Apical Meristem Through Regulating the Number of Indeterminate Cells

Genetics ◽  
2003 ◽  
Vol 164 (1) ◽  
pp. 335-346
Author(s):  
Namiko Satoh ◽  
Jun-Ichi Itoh ◽  
Yasuo Nagato
Keyword(s):  
Seed Development ◽  
Shoot Apical Meristem ◽  
Double Mutant ◽  
Apical Meristem ◽  
Leaf Primordium ◽  
Shoot Meristem ◽  
Expression Domain ◽  
Positive Correlation

Abstract To characterize the SHL2 and SHL1 genes in detail, we analyzed three strains carrying weak alleles of SHL2, shl2-6, shl2-7, and shl2-8, and one weak allele of SHL1, shl1-3. In contrast to strong alleles, which result in lack of shoot meristem, strains bearing these weak alleles formed shoot meristem frequently during embryogenesis. In shl2-6 and shl2-7 mutants, the meristem was lost during seed development. Only the shl2-8 mutant could survive after germination, but it showed abnormal initiation pattern and morphology of leaves. In strains bearing the weak alleles, the shoot meristem was composed of a small number of indeterminate cells and ultimately converted into leaf primordium. The shl1-3 mutant showed phenotypes similar to those of shl2-8. Thus SHL2 and SHL1 are required for both initiation and maintenance of shoot meristem. In shl2 mutants, there was a positive correlation between the size of the expression domain of OSH1 representing the number of indeterminate cells, the frequency of shoot meristem initiation, and the duration of meristem survival. Thus the shoot meristem will not initiate in an “all-or-nothing” fashion, but is formed in various degrees depending on the strength of the alleles. Double-mutant analyses indicate that SHL2 functions upstream of SHO to establish proper organization of the shoot meristem.

scholarly journals Sample preparation for laser-microdissection of soybean shoot apical meristem

2012 ◽  
Vol 3 (1) ◽  
pp. 3 ◽  
Author(s):  
Chui E. Wong ◽  
Mohan B. Singh ◽  
Prem L. Bhalla
Keyword(s):  
Sample Preparation ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Laser Microdissection ◽  
Specific Cell ◽  
Legume Crop ◽  
Continuous Formation ◽  
Molecular Events ◽  
Depth Analysis ◽  
Specialized Equipment

The shoot apical meristem houses stem cells responsible for the continuous formation of aerial plant organs including leaves and stems throughout the life of plants. Laser-microdissection in combination with high-throughput technology such as next generation sequencing permits an in-depth analysis of molecular events associated with specific cell type of interest. Sample preparation is the most critical step in ensuring good quality RNA to be extracted from samples following laser-microdissection. Here, we optimized the sample preparation for a major legume crop, soybean. We used Farmer’s solution as a fixative and paraffin as the embedding medium for soybean shoot apical meristem tissue without the use of any specialized equipment. Shorter time for tissue fixation (two days) was found to be critical for the preservation of RNA in soybean shoot apical meristem. We further demonstrated the utility of this method for different tissues derived from soybean and rice. The method outlined here shall facilitate studies on crop plants involving laser-microdissection.

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