The CUP-SHAPED COTYLEDON1 gene of Arabidopsis regulates shoot apical meristem formation

Development ◽  
2001 ◽  
Vol 128 (7) ◽  
pp. 1127-1135 ◽  
Author(s):  
S. Takada ◽  
K. Hibara ◽  
T. Ishida ◽  
M. Tasaka
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Molecular Mechanisms ◽  
Higher Plants ◽  
Adventitious Shoots ◽  
Floral Organ ◽  
Loss Of Function ◽  
Nac Domain ◽  
Redundant Genes ◽  
Domain Protein

In higher plants, molecular mechanisms regulating shoot apical meristem (SAM) formation and organ separation are largely unknown. The CUC1 (CUP-SHAPED COTYLEDON1) and CUC2 are functionally redundant genes that are involved in these processes. We cloned the CUC1 gene by a map-based approach, and found that it encodes a NAC-domain protein highly homologous to CUC2. CUC1 mRNA was detected in the presumptive SAM during embryogenesis, and at the boundaries between floral organ primordia. Surprisingly, overexpression of CUC1 was sufficient to induce adventitious shoots on the adaxial surface of cotyledons. Expression analyses in the overexpressor and in loss-of-function mutants suggest that CUC1 acts upstream of the SHOOT MERISTEMLESS gene.

Embryonic shoot apical meristem formation in higher plants

2002 ◽  
Vol 115 (6) ◽  
pp. 411-417 ◽  
Author(s):  
Shinobu Takada ◽  
Masao Tasaka
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Higher Plants

scholarly journals A quantitative gibberellin signalling biosensor reveals a role for gibberellins in internode specification at the shoot apical meristem

2021 ◽  
Author(s):  
Bihai Shi ◽  
Amelia Felipo-Benavent ◽  
Guillaume Cerutti ◽  
Carlos Galvan-Ampudia ◽  
Lucas Jilli ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Regulatory Function ◽  
Loss Of Function ◽  
Transcriptional Responses ◽  
Division Plane ◽  
Cellular Changes ◽  
Shoot Architecture ◽  
Division Plane Orientation ◽  
Cell Division Plane

Growth at the shoot apical meristem (SAM) is essential for shoot architecture construction. The phytohormones gibberellins (GA) play a pivotal role in coordinating plant growth, but their role in the SAM remains mostly unknown. Here, we developed a ratiometric GA signalling biosensor by engineering one of the DELLA repressors, to suppress its master regulatory function in GA transcriptional responses while preserving its degradation upon GA sensing. We demonstrate that this novel degradation-based biosensor accurately reports on cellular changes in GA levels and perception during development. We used this biosensor to map GA signalling activity in the SAM. We show that high GA signalling is found primarily in cells located between organ primordia that are the precursors of internodes. By gain- and loss-of-function approaches, we further demonstrate that GAs regulate cell division plane orientation to establish the typical cellular organisation of internodes, thus contributing to internode specification in the SAM.

Initiation of shoot apical meristem in rice: characterization of four SHOOTLESS genes

Development ◽  
1999 ◽  
Vol 126 (16) ◽  
pp. 3629-3636 ◽  
Author(s):  
N. Satoh ◽  
S.K. Hong ◽  
A. Nishimura ◽  
M. Matsuoka ◽  
H. Kitano ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Adventitious Shoots ◽  
Homeobox Gene ◽  
Hybridization Experiment ◽  
Expression Domain ◽  
Recessive Mutations ◽  
Normal Expression ◽  
Extensive Growth

The regulatory mechanism of shoot apical meristem (SAM) initiation is an important subject in developmental plant biology. We characterized nine recessive mutations derived from four independent loci (SHL1-SHL4) causing the deletion of the SAM. Radicles were produced in these mutant embryos. Concomitant with the loss of SAM, two embryo-specific organs, coleoptile and epiblast, were lost, but the scutellum was formed normally. Therefore, differentiation of radicle and scutellum is regulated independently of SAM, but that of coleoptile and epiblast may depend on SAM. Regeneration experiments using adventitious shoots from the scutellum-derived calli showed that no adventitious shoots were regenerated in any shl mutant. However, small adventitious leaves were observed in both mutant and wild-type calli, but they soon became necrotic and showed no extensive growth. Thus, leaf primordia can initiate in the absence of SAM, but their extensive growth requires the SAM. An in situ hybridization experiment using a rice homeobox gene, OSH1, as a probe revealed that shl1 and shl2 modified the expression domain of OSH1, but normal expression of OSH1 was observed in shl3 and shl4 embryos. Accordingly, SHL1 and SHL2 function upstream of OSH1, and SHL3 and SHL4 downstream or independently of OSH1. These shl mutants are useful for elucidating the genetic program driving SAM initiation and for unraveling the interrelationships among various organs in grass embryos.

scholarly journals WUSCHEL in the shoot apical meristem: old player, new tricks

2020 ◽  
Author(s):  
Filipa Lopes ◽  
Carlos Galvan-Ampudia ◽  
Benoit Landrein
Keyword(s):  
Stem Cell ◽  
Cell Fate ◽  
Shoot Apical Meristem ◽  
Feedback Loop ◽  
Apical Meristem ◽  
Molecular Mechanisms ◽  
Central Zone ◽  
Environmental Signals ◽  
Plant Environment ◽  
Organizing Center

Abstract The maintenance of the stem cell niche in the shoot apical meristem, the structure that generates all of the aerial organs of the plant, relies on a canonical feedback loop between WUSCHEL (WUS) and CLV3 (CLV3). WUS is a homeodomain transcription factor expressed in the organizing center that moves to the central zone to promote stem cell fate. CLAVATA3 is a peptide whose expression is induced by WUS in the central zone that can move back to the organizing center to inhibit WUS expression. Within the last 20 years since the initial formulation of the CLV/WUS feedback loop, the mechanisms of stem cell maintenance have been intensively studied and the function of WUS has been redefined. In this review, we will highlight the most recent advances in our comprehension of the molecular mechanisms of WUS function, of its interaction with other transcription factors and with hormonal signals and of its connection to environmental signals. Through this, we will show how WUS can integrate both internal and external cues to adapt meristem function to the plant environment.

Shoot apical meristem and cotyledon formation during Arabidopsis embryogenesis: interaction among the CUP-SHAPED COTYLEDON and SHOOT MERISTEMLESS genes

Development ◽  
1999 ◽  
Vol 126 (8) ◽  
pp. 1563-1570 ◽  
Author(s):  
M. Aida ◽  
T. Ishida ◽  
M. Tasaka
Keyword(s):  
Pattern Formation ◽  
Mrna Expression ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Higher Plants ◽  
Expression Patterns ◽  
Genetic Interactions ◽  
Apical Region ◽  
Arabidopsis Embryogenesis ◽  
Shoot Meristemless

The shoot apical meristem and cotyledons of higher plants are established during embryogenesis in the apex. Redundant CUP-SHAPED COTYLEDON 1 (CUC1) and CUC2 as well as SHOOT MERISTEMLESS (STM) of Arabidopsis are required for shoot apical meristem formation and cotyledon separation. To elucidate how the apical region of the embryo is established, we investigated genetic interactions among CUC1, CUC2 and STM, as well as the expression patterns of CUC2 and STM mRNA. Expression of these genes marked the incipient shoot apical meristem as well as the boundaries of cotyledon primordia, consistent with their roles for shoot apical meristem formation and cotyledon separation. Genetic and expression analyses indicate that CUC1 and CUC2 are redundantly required for expression of STM to form the shoot apical meristem, and that STM is required for proper spatial expression of CUC2 to separate cotyledons. A model for pattern formation in the apical region of the Arabidopsis embryo is presented.

scholarly journals AGLF provides C-function in floral organ identity through transcriptional regulation of AGAMOUS in Medicago truncatula

2019 ◽  
Vol 116 (11) ◽  
pp. 5176-5181 ◽  
Author(s):  
Yang Zhao ◽  
Rong Liu ◽  
Yiteng Xu ◽  
Minmin Wang ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Flower Development ◽  
Molecular Mechanisms ◽  
Floral Organ ◽  
Model Systems ◽  
Loss Of Function ◽  
Model Legume ◽  
Floral Organ Identity ◽  
Organ Identity ◽  
Class B

Floral development is one of the model systems for investigating the mechanisms underlying organogenesis in plants. Floral organ identity is controlled by the well-known ABC model, which has been generalized to many flowering plants. Here, we report a previously uncharacterized MYB-like gene, AGAMOUS-LIKE FLOWER (AGLF), involved in flower development in the model legume Medicago truncatula. Loss-of-function of AGLF results in flowers with stamens and carpel transformed into extra whorls of petals and sepals. Compared with the loss-of-function mutant of the class C gene AGAMOUS (MtAG) in M. truncatula, the defects in floral organ identity are similar between aglf and mtag, but the floral indeterminacy is enhanced in the aglf mutant. Knockout of AGLF in the mutants of the class A gene MtAP1 or the class B gene MtPI leads to an addition of a loss-of-C-function phenotype, reflecting a conventional relationship of AGLF with the canonical A and B genes. Furthermore, we demonstrate that AGLF activates MtAG in transcriptional levels in control of floral organ identity. These data shed light on the conserved and diverged molecular mechanisms that control flower development and morphology among plant species.

scholarly journals The CLV-WUS Stem Cell Signaling Pathway: A Roadmap to Crop Yield Optimization

Plants ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 87 ◽  
Author(s):  
Jennifer Fletcher
Keyword(s):  
Stem Cell ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Higher Plants ◽  
Yield Traits ◽  
Yield Optimization ◽  
Agricultural Plant ◽  
Stem Cell Maintenance ◽  
Model Plant Arabidopsis Thaliana ◽  
Floral Meristems

The shoot apical meristem at the growing shoot tip acts a stem cell reservoir that provides cells to generate the entire above-ground architecture of higher plants. Many agronomic plant yield traits such as tiller number, flower number, fruit number, and kernel row number are therefore defined by the activity of the shoot apical meristem and its derivatives, the floral meristems. Studies in the model plant Arabidopsis thaliana demonstrated that a molecular negative feedback loop called the CLAVATA (CLV)-WUSCHEL (WUS) pathway regulates stem cell maintenance in shoot and floral meristems. CLV-WUS pathway components are associated with quantitative trait loci (QTL) for yield traits in crop plants such as oilseed, tomato, rice, and maize, and may have played a role in crop domestication. The conservation of these pathway components across the plant kingdom provides an opportunity to use cutting edge techniques such as genome editing to enhance yield traits in a wide variety of agricultural plant species.

scholarly journals C2cd6-encoded CatSperτ Targets Sperm Calcium Channel to Ca2+ Signaling Domains in the Flagellar Membrane

2021 ◽  
Author(s):  
Jae Yeon Hwang ◽  
Huafeng Wang ◽  
Yonggang Lu ◽  
Masahito Ikawa ◽  
Jean-Ju Chung
Keyword(s):  
Male Fertility ◽  
Molecular Mechanisms ◽  
Dependent Manner ◽  
Loss Of Function ◽  
Channel Trafficking ◽  
Mammalian Sperm ◽  
Flagellar Membrane ◽  
Domain Protein ◽  
Channel Assembly ◽  
Signaling Domains

In mammalian sperm cells, regulation of spatiotemporal Ca2+ signaling relies on the quadrilinear Ca2+ signaling nanodomains in the flagellar membrane. The sperm-specific, multi-subunit CatSper Ca2+ channel, which is crucial for sperm hyperactivated motility and male fertility, organizes the nanodomains. Here, we report CatSperτ, the C2cd6-encoded membrane-associating C2 domain protein, can independently migrate to the flagella and serve as a major targeting component of the CatSper channel complex. CatSperτ loss-of-function in mice demonstrates that it is essential for sperm hyperactivated motility and male fertility. CatSperτ targets the CatSper channel into the quadrilinear nanodomains in the flagella of developing spermatids, whereas it is dispensable for functional channel assembly. CatSperτ interacts with ciliary trafficking machinery in a C2-dependent manner. These findings provide insights into the CatSper channel trafficking to the Ca2+ signaling nanodomains and the shared molecular mechanisms of ciliary and flagellar membrane targeting.

scholarly journals Rolesof plant growth regulators on the shoot development from the shoot apical meristem of Eustoma grandiflorum (RAF.) shinners

2018 ◽  
Vol 1 (6) ◽  
pp. 58-67
Author(s):  
Huyen Thach Quynh Ngo ◽  
Huong Thanh Tran ◽  
Viet Trang Bui
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Adventitious Shoots ◽  
Shoot Development ◽  
Ms Medium ◽  
Eustoma Grandiflorum ◽  
Shoot Initiation

In this paper, plant growth regulators including 6-benzylaminopurine (BA), kinetin, indole-3-acetic acid (IAA), gibberellic acid (GA3) and ethrel, at different concentrations were used individually or in combination to induce adventitious shoots from the explants, which contain shoot apical meristem and young leaves. Histological and physiological changes during shoot development were analysed. The highest shoot initiation was achieved on Murashige and Skoog (MS) medium supplemented with 0.5 mg/L BA and 1.0 mg/L GA3. Regenerated shoots were rooted on MS medium with 0.25 or 0.5 mg/L IAA. Shoot development from in vitro shoot explants initiated from the axil and cortex of stem. The shoot regeneration from shoot apical explants was effected by the meristem integrity or auxin from shoot apical meristem. Roles of plant growth regulators, especially polar auxin transport, and the ablation on the shoot initiation were discussed.

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