The REVOLUTA gene is necessary for apical meristem development and for limiting cell divisions in the leaves and stems of Arabidopsis thaliana

The form of seed plants is determined by the growth of a number of meristems including apical meristems, leaf meristems and cambium layers. We investigated five recessive mutant alleles of a gene REVOLUTA that is required to promote the growth of apical meristems and to limit cell division in leaves and stems of Arabidopsis thaliana. REVOLUTA maps to the bottom of the fifth chromosome. Apical meristems of both paraclades (axillary shoots) and flowers of revoluta mutants frequently fail to complete normal development and form incomplete or abortive structures. The primary shoot apical meristem sometimes also arrests development early. Leaves, stems and floral organs, in contrast, grow abnormally large. We show that in the leaf epidermis this extra growth is due to extra cell divisions in the leaf basal meristem. The extent of leaf growth is negatively correlated with the development of a paraclade in the leaf axil. The thickened stems contain extra cell layers, arranged in rings, indicating that they may result from a cambium-like meristem. These results suggest that the REVOLUTA gene has a role in regulating the relative growth of apical and non-apical meristems in Arabidopsis.

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Class I KNOX Is Related to Determinacy during the Leaf Development of the Fern Mickelia scandens (Dryopteridaceae)

International Journal of Molecular Sciences ◽

10.3390/ijms21124295 ◽

2020 ◽

Vol 21 (12) ◽

pp. 4295 ◽

Cited By ~ 4

Author(s):

Rafael Cruz ◽

Gladys F. A. Melo-de-Pinna ◽

Alejandra Vasco ◽

Jefferson Prado ◽

Barbara A. Ambrose

Keyword(s):

Leaf Development ◽

Apical Meristem ◽

Class I ◽

Seed Plants ◽

Histone H4 ◽

Knox Genes ◽

Apical Meristems ◽

Cell Divisions ◽

Shoot Apical Meristems

Unlike seed plants, ferns leaves are considered to be structures with delayed determinacy, with a leaf apical meristem similar to the shoot apical meristems. To better understand the meristematic organization during leaf development and determinacy control, we analyzed the cell divisions and expression of Class I KNOX genes in Mickelia scandens, a fern that produces larger leaves with more pinnae in its climbing form than in its terrestrial form. We performed anatomical, in situ hybridization, and qRT-PCR experiments with histone H4 (cell division marker) and Class I KNOX genes. We found that Class I KNOX genes are expressed in shoot apical meristems, leaf apical meristems, and pinnae primordia. During early development, cell divisions occur in the most distal regions of the analyzed structures, including pinnae, and are not restricted to apical cells. Fern leaves and pinnae bear apical meristems that may partially act as indeterminate shoots, supporting the hypothesis of homology between shoots and leaves. Class I KNOX expression is correlated with indeterminacy in the apex and leaf of ferns, suggesting a conserved function for these genes in euphyllophytes with compound leaves.

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Cell fate in the shoot apical meristem of Arabidopsis thaliana

Development ◽

10.1242/dev.115.3.755 ◽

1992 ◽

Vol 115 (3) ◽

pp. 755-764 ◽

Cited By ~ 9

Author(s):

J. Furner I ◽

J. E. Pumfrey

Keyword(s):

Arabidopsis Thaliana ◽

Cell Fate ◽

Apical Meristem ◽

Higher Plants ◽

Great Majority ◽

Shoot Meristem ◽

X Rays ◽

Developmental Fate ◽

Axillary Meristems ◽

Cell Layers

Seeds of Arabidopsis thaliana, heterozygous for the alb1 mutation were treated with X-rays to generate sectors of albino tissue in the mature plants. Sectors were observed in tissues derived from L2 and L3 layers of the shoot meristem. Altogether 324 sectors were obtained affecting 512 leaves or the inflorescence. The majority of sectors affected only one or other of the first leaf pair. In later leaves, sectors were less frequent, and often affected more than one leaf. Sectors seen in the flowers almost invariably included some of the cauline leaves. Sectors in any region of the plant were of variable length and width. The axillary meristems of Arabidopsis were found to be clonally related to two or more cells near the centre of the subtending leaf. Overall the data are compatible with the idea that there are few, if any, restrictions on cell fate within the cell layers of the dry seed meristem. As in other higher plants, developmental fate could only be predicted in a general and probabilistic way. Such a pattern might be generated if the acquisition of cell fate occurred continuously as the plant grows, in a position-dependent, lineage-independent fashion. A general model of the meristem has been produced to accommodate the observations concerning the great majority of the sectors.

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Active suppression of a leaf meristem orchestrates determinate leaf growth

eLife ◽

10.7554/elife.15023 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 58

Author(s):

John Paul Alvarez ◽

Chihiro Furumizu ◽

Idan Efroni ◽

Yuval Eshed ◽

John L Bowman

Keyword(s):

Arabidopsis Thaliana ◽

Transcription Factors ◽

Leaf Growth ◽

Seed Plant ◽

Plant Leaves ◽

Active Suppression ◽

Anatomical Features ◽

Apical Meristems ◽

Shoot Apical Meristems ◽

Shoot System

Leaves are flat determinate organs derived from indeterminate shoot apical meristems. The presence of a specific leaf meristem is debated, as anatomical features typical of meristems are not present in leaves. Here we demonstrate that multiple NGATHA (NGA) and CINCINNATA-class-TCP (CIN-TCP) transcription factors act redundantly, shortly after leaf initiation, to gradually restrict the activity of a leaf meristem in Arabidopsis thaliana to marginal and basal domains, and that their absence confers persistent marginal growth to leaves, cotyledons and floral organs. Following primordia initiation, the restriction of the broadly acting leaf meristem to the margins is mediated by the juxtaposition of adaxial and abaxial domains and maintained by WOX homeobox transcription factors, whereas other marginal elaboration genes are dispensable for its maintenance. This genetic framework parallels the morphogenetic program of shoot apical meristems and may represent a relic of an ancestral shoot system from which seed plant leaves evolved.

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Activities of Chromatin Remodeling Factors and Histone Chaperones and Their Effects in Root Apical Meristem Development

International Journal of Molecular Sciences ◽

10.3390/ijms21030771 ◽

2020 ◽

Vol 21 (3) ◽

pp. 771

Author(s):

Huijia Kang ◽

Di Wu ◽

Tianyi Fan ◽

Yan Zhu

Keyword(s):

Chromatin Remodeling ◽

Apical Meristem ◽

Plant Root ◽

Root Apical Meristem ◽

Histone Chaperones ◽

Apical Meristems ◽

Transcriptional Reprogramming ◽

Eukaryotic Genes ◽

Cell Proliferation And Differentiation ◽

Meristem Development

Eukaryotic genes are packaged into dynamic but stable chromatin structures to deal with transcriptional reprogramming and inheritance during development. Chromatin remodeling factors and histone chaperones are epigenetic factors that target nucleosomes and/or histones to establish and maintain proper chromatin structures during critical physiological processes such as DNA replication and transcriptional modulation. Root apical meristems are vital for plant root development. Regarding the well-characterized transcription factors involved in stem cell proliferation and differentiation, there is increasing evidence of the functional implications of epigenetic regulation in root apical meristem development. In this review, we focus on the activities of chromatin remodeling factors and histone chaperones in the root apical meristems of the model plant species Arabidopsis and rice.

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CLAVATA3 is a specific regulator of shoot and floral meristem development affecting the same processes as CLAVATA1

Development ◽

10.1242/dev.121.7.2057 ◽

1995 ◽

Vol 121 (7) ◽

pp. 2057-2067 ◽

Cited By ~ 26

Author(s):

S. E. Clark ◽

M. P. Running ◽

E. M. Meyerowitz

Keyword(s):

Arabidopsis Thaliana ◽

Flower Development ◽

Mature Embryo ◽

Floral Meristem ◽

Wild Type ◽

Apical Meristems ◽

Meristem Development ◽

Embryo Stage ◽

Double Heterozygosity ◽

Floral Meristems

We have previously described the phenotype of Arabidopsis thaliana plants with mutations at the CLAVATA1 (CLV1) locus (Clark, S. E., Running, M. P. and Meyerowitz, E. M. (1993) Development 119, 397–418). Our investigations demonstrated that clv1 plants develop enlarged vegetative and inflorescence apical meristems, and enlarged and indeterminate floral meristems. Here, we present an analysis of mutations at a separate locus, CLAVATA3 (CLV3), that disrupt meristem development in a manner similar to clv1 mutations. clv3 plants develop enlarged apical meristems as early as the mature embryo stage. clv3 floral meristems are also enlarged compared with wild type, and maintain a proliferating meristem throughout flower development. clv3 root meristems are unaffected, indicating that CLV3 is a specific regulator of shoot and floral meristem development. We demonstrate that the strong clv3-2 mutant is largely epistatic to clv1 mutants, and that the semi- dominance of clv1 alleles is enhanced by double heterozygosity with clv3 alleles, suggesting that these genes work in the same pathway to control meristem development. We propose that CLV1 and CLV3 are required to promote the differentiation of cells at the shoot and floral meristem.

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Faculty Opinions recommendation of Real-time lineage analysis reveals oriented cell divisions associated with morphogenesis at the shoot apex of Arabidopsis thaliana.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1020414.237441 ◽

2004 ◽

Author(s):

Kay Schneitz

Keyword(s):

Arabidopsis Thaliana ◽

Real Time ◽

Shoot Apex ◽

Cell Divisions ◽

Lineage Analysis

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Faculty Opinions recommendation of Real-time lineage analysis reveals oriented cell divisions associated with morphogenesis at the shoot apex of Arabidopsis thaliana.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1020414.234464 ◽

2004 ◽

Author(s):

Elena Alvarez-Buylla

Keyword(s):

Arabidopsis Thaliana ◽

Real Time ◽

Shoot Apex ◽

Cell Divisions ◽

Lineage Analysis

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Sound Waves Promote Arabidopsis thaliana Root Growth by Regulating Root Phytohormone Content

International Journal of Molecular Sciences ◽

10.3390/ijms22115739 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5739

Author(s):

Joo Yeol Kim ◽

Hyo-Jun Lee ◽

Jin A Kim ◽

Mi-Jeong Jeong

Keyword(s):

Arabidopsis Thaliana ◽

Cell Division ◽

Root Growth ◽

Apical Meristem ◽

Cell Number ◽

Root Apical Meristem ◽

Control Group ◽

Auxin Signaling ◽

Ethylene Signaling ◽

Sound Waves

Sound waves affect plants at the biochemical, physical, and genetic levels. However, the mechanisms by which plants respond to sound waves are largely unknown. Therefore, the aim of this study was to examine the effect of sound waves on Arabidopsis thaliana growth. The results of the study showed that Arabidopsis seeds exposed to sound waves (100 and 100 + 9k Hz) for 15 h per day for 3 day had significantly longer root growth than that in the control group. The root length and cell number in the root apical meristem were significantly affected by sound waves. Furthermore, genes involved in cell division were upregulated in seedlings exposed to sound waves. Root development was affected by the concentration and activity of some phytohormones, including cytokinin and auxin. Analysis of the expression levels of genes regulating cytokinin and auxin biosynthesis and signaling showed that cytokinin and ethylene signaling genes were downregulated, while auxin signaling and biosynthesis genes were upregulated in Arabidopsis exposed to sound waves. Additionally, the cytokinin and auxin concentrations of the roots of Arabidopsis plants increased and decreased, respectively, after exposure to sound waves. Our findings suggest that sound waves are potential agricultural tools for improving crop growth performance.

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The ATXN2 Orthologs CID3 and CID4, Act Redundantly to In-Fluence Developmental Pathways throughout the Life Cycle of Arabidopsis thaliana

International Journal of Molecular Sciences ◽

10.3390/ijms22063068 ◽

2021 ◽

Vol 22 (6) ◽

pp. 3068

Author(s):

Zaira M. López-Juárez ◽

Laura Aguilar-Henonin ◽

Plinio Guzmán

Keyword(s):

Arabidopsis Thaliana ◽

Life Cycle ◽

Binding Proteins ◽

Rna Binding ◽

Rna Binding Proteins ◽

Leaf Growth ◽

Transcriptome Profiling ◽

Developmental Pathways ◽

Model Organisms ◽

Key Factors

RNA-binding proteins (RBPs) are key elements involved in post-transcriptional regulation. Ataxin-2 (ATXN2) is an evolutionarily conserved RBP protein, whose function has been studied in several model organisms, from Saccharomyces cerevisiae to the Homo sapiens. ATXN2 interacts with poly(A) binding proteins (PABP) and binds to specific sequences at the 3′UTR of target mRNAs to stabilize them. CTC-Interacting Domain3 (CID3) and CID4 are two ATXN2 orthologs present in plant genomes whose function is unknown. In the present study, phenotypical and transcriptome profiling were used to examine the role of CID3 and CID4 in Arabidopsis thaliana. We found that they act redundantly to influence pathways throughout the life cycle. cid3cid4 double mutant showed a delay in flowering time and a reduced rosette size. Transcriptome profiling revealed that key factors that promote floral transition and floral meristem identity were downregulated in cid3cid4 whereas the flowering repressor FLOWERING LOCUS C (FLC) was upregulated. Expression of key factors in the photoperiodic regulation of flowering and circadian clock pathways, were also altered in cid3cid4, as well as the expression of several transcription factors and miRNAs encoding genes involved in leaf growth dynamics. These findings reveal that ATXN2 orthologs may have a role in developmental pathways throughout the life cycle of plants.

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