scholarly journals Occurrence of the Transition of Apical Architecture and Expression Patterns of Related Genes during Conversion of Apical Meristem Identity in G2 Pea

2009 ◽  
Vol 51 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Da-Yong Wang ◽  
Qing Li ◽  
Ke-Ming Cui ◽  
Yu-Xian Zhu
Keyword(s):  
Apical Meristem ◽  
Expression Patterns ◽  
Meristem Identity ◽  
G2 Pea

scholarly journals CLAVATA1, a regulator of meristem and flower development in Arabidopsis

Development ◽  
1993 ◽  
Vol 119 (2) ◽  
pp. 397-418 ◽  
Author(s):  
S.E. Clark ◽  
M.P. Running ◽  
E.M. Meyerowitz
Keyword(s):  
Flower Development ◽  
Double Mutant ◽  
Apical Meristem ◽  
Expression Patterns ◽  
Floral Meristem ◽  
Homeotic Genes ◽  
Wild Type ◽  
Meristem Identity ◽  
Floral Meristems ◽  
Transition To Flowering

We have investigated the effects on plant development of mutations in the Arabidopsis thaliana CLAVATA1 gene. In clavata1 plants, vegetative, inflorescence and floral meristems are all enlarged relative to wild type. The apical meristem can fasciate in the more severe mutant alleles, and this fasciation can occur prior to the transition to flowering. Flowers of clavata1 plants can have increased numbers of organs in all four whorls, and can also have additional whorls not present in wild-type flowers. Double mutant combinations of clavata1 with agamous, apetala2, apetala3 and pistillata indicate that CLAVATA1 controls the underlying floral meristem structure upon which these homeotic genes act. Double mutant combinations of clavata1 with apetala1 and leafy indicate CLAVATA1 plays a role in establishing and maintaining floral meristem identity, in addition to its role in controlling meristem size. In support of this, RNA expression patterns of AGAMOUS and APETALA1 are altered in clavata1 flowers.

scholarly journals Extended expression of MaKN1 contributes to the leaf morphology in aquatic forms of Myriophyllum aquaticum

Botany ◽  
2015 ◽  
Vol 93 (9) ◽  
pp. 611-621
Author(s):  
M.D. Shafiullah ◽  
Christian R. Lacroix
Keyword(s):  
Apical Meristem ◽  
Leaf Morphology ◽  
Expression Patterns ◽  
Homeobox Gene ◽  
Leaf Primordia ◽  
Leaf Primordium ◽  
Myriophyllum Aquaticum ◽  
Knox Gene ◽  
Leaf Morphogenesis

Myriophyllum aquaticum (Vell.) Verdc. is heterophyllous in nature with highly dissected simple leaves consisting of several lobes. KNOX (KNOTTED1-LIKE HOMEOBOX) genes are believed to have played an important role in the evolution of leaf diversity. Up-regulation of KNOX during leaf primordium initiation can lead to leaf dissection in plants with simple leaves and, if overexpressed, can produce ectopic meristems on leaves. A previous study on KNOX gene expression in the aerial form of this species showed that this gene is expressed in the shoot apical meristem (SAM), as well as in leaf primordia P0 to P8. Based on these results, it was hypothesized that the prolonged expression of the MaKN1 (Myriophyllum aquaticum Knotted1-like homeobox) gene beyond P8, might play an important role in the generation of more lobes, longer lobes, and hydathode formation in the aquatic leaves of M. aquaticum. The technique of in situ hybridization was carried out using a previously sequenced 300 bp fragment of MaKN1 to determine the expression patterns of this gene in the shoot of aquatic forms of the plant. Expression patterns of MaKN1 revealed that the SAM and leaf primordia of aquatic forms of M. aquaticum at levels P0 (youngest) to P4 were distributed throughout these structures. The level of expression of this MaKN1 gene progressively became more localized to lobes in older leaf primordia (levels P5 to P12). Previous studies of aerial forms of this plant showed MaKN1 expression until P8. Our results with aquatic forms show that the highly dissected leaf morphology in aquatic forms was the result of the prolonged expression of MaKN1 beyond P8. This resulted in the formation of elongated and slightly more numerous lobes, and hydathodes in aquatic forms. These findings support the view that KNOX genes are important developmental regulators of leaf morphogenesis and have played an important role in the evolution of leaf forms in the plant kingdom.

scholarly journals Flowering time and the identification of floral marker genes in Solanum tuberosum ssp. andigena

2019 ◽  
Vol 71 (3) ◽  
pp. 986-996 ◽  
Author(s):  
Tanja Seibert ◽  
Christin Abel ◽  
Vanessa Wahl
Keyword(s):  
Flowering Time ◽  
Developmental Stages ◽  
Expression Patterns ◽  
Marker Genes ◽  
Flower Meristem ◽  
Growth Regime ◽  
Long Day ◽  
Storage Organs ◽  
Meristem Identity ◽  
Meristem Identity Gene

Abstract Solanaceae is a family of flowering plants that includes agricultural species such as tomato (Solanum lycopersicum), eggplant (S. melongena), pepper (Capsicum annuum), and potato (S. tuberosum). The transition from the vegetative to reproductive stage has been extensively investigated in tomato as it affects fruit yield. While potato has mainly been studied with regards to the formation of storage organs, control of flowering time is a subject of increasing interest as development of true seeds is becoming more important for future breeding strategies. Here, we describe a robust growth regime for synchronized development of S. tuberosum ssp. andigena. Using SEM to analyse the developmental stages of the shoot apical meristem (SAM) throughout the floral transition, we show that andigena is a facultative long-day plant with respect to flowering. In addition, we identify the flower meristem identity gene MACROCALYX (StMC) as a marker to distinguish between the vegetative and reproductive stages. We show that the expression of WUSCHEL HOMEOBOX 9 (StWOX9) and ANANTHA (StAN) are specific to the inflorescence meristem and flower meristems in the cyme, respectively. The expression patterns of homologs of Arabidopsis flowering-time regulators were studied, and indicated that SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (StSOC1) and StFD might regulate flowering similar to other plant species.

scholarly journals Control of stem-cell niche establishment in Arabidopsis flowers by REVOLUTA and the LEAFY-RAX1 module

2018 ◽  
Author(s):  
Denay Grégoire ◽  
Tichtinsky Gabrielle ◽  
Le Masson Marie ◽  
Chahtane Hicham ◽  
Huguet Sylvie ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Niche ◽  
Apical Meristem ◽  
Molecular Mechanisms ◽  
Floral Initiation ◽  
Flower Primordia ◽  
Meristem Identity ◽  
Cell Niche ◽  
Early Flower ◽  
Stem Cell Niches

AbstractPlants retain the ability to produce organs throughout their life by maintaining active stem cell niches called meristems. The shoot apical meristem (SAM) is responsible for the growth of aerial plant structures. In Arabidopsis thaliana, the SAM initially produces leaves during the vegetative phase and later flowers during reproductive development. In the early stages of floral initiation, a group of cells first emerges from the SAM to form a stereotypically organized meristematic structure on its flank. However, the molecular mechanisms underlying the acquisition of this specific meristematic organization remain elusive. We show here that the transcription factors LEAFY (LFY) and REVOLUTA (REV) control two partially redundant pathways controlling meristematic organization in early flower primordia. We found that LFY acts through the transcription factor REGULATOR OF AXILLARY MERISTEM1 (RAX1) and we provide mechanistic insights in how RAX1 allows meristem identity establishment in young flowers. Our work provides a molecular link between the processes of meristem formation and floral identity acquisition in the nascent flower.

scholarly journals The shoot apical meristem: the dynamics of a stable structure

2002 ◽  
Vol 357 (1422) ◽  
pp. 737-747 ◽  
Author(s):  
Jan Traas ◽  
Teva Vernoux
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Apparent Contradiction ◽  
Cell Behaviour ◽  
Aerial Parts ◽  
Meristem Identity ◽  
Set Up ◽  
The Stability ◽  
Kinase Pathway ◽  
Stable Network

The shoot apical meristem (SAM) is a group of proliferating, embryonic–type cells that generates the aerial parts of the plant. SAMs are highly organized and stable structures that can function for years or even centuries. This is in apparent contradiction to the behaviour of their constituent cells, which continuously proliferate and differentiate. To reconcile the dynamic nature of the cells with the stability of the overall system the existence of elaborate signalling networks has been proposed. This is supported by recent work suggesting that the exchange of signals between cells, rather than a rigidly predetermined genetic program, is required for the establishment and functioning of an organized meristem. Together these interactions form a stable network, set up during embryogenesis, that assures the coordination of cell behaviour throughout development. Besides meristem–specific signalling cascades such as the CLAVATA receptor kinase pathway, which controls meristem size, these interactions involve plant hormones. In particular, cytokinins and auxins are implicated in the maintenance of meristem identity and phyllotaxis, respectively.

scholarly journals The ERECTA receptor kinase regulates Arabidopsis shoot apical meristem size, phyllotaxy and floral meristem identity

Development ◽  
2014 ◽  
Vol 141 (4) ◽  
pp. 830-841 ◽  
Author(s):  
T. Mandel ◽  
F. Moreau ◽  
Y. Kutsher ◽  
J. C. Fletcher ◽  
C. C. Carles ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Floral Meristem ◽  
Receptor Kinase ◽  
Floral Meristem Identity ◽  
Meristem Size ◽  
Meristem Identity

The shoot apical meristem and development of vascular architectureThis review is one of a selection of papers published on the Special Theme of Shoot Apical Meristems.

2006 ◽  
Vol 84 (11) ◽  
pp. 1660-1671 ◽  
Author(s):  
Nancy G. Dengler
Keyword(s):  
Arabidopsis Thaliana ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Leucine Zipper ◽  
Vascular Tissue ◽  
Vascular System ◽  
Expression Patterns ◽  
Three Dimensional ◽  
Integrative Model ◽  
Class Iii

The shoot apical meristem (SAM) functions to generate external architecture and internal tissue pattern as well as to maintain a self-perpetuating population of stem-cell-like cells. The internal three-dimensional architecture of the vascular system corresponds closely to the external arrangement of lateral organs, or phyllotaxis. This paper reviews this correspondence for dicotyledonous plants in general and in Arabidopsis thaliana (L.) Heynh., specifically. Analysis is partly based on the expression patterns of the class III homeodomain-leucine zipper transcription factor ARABIDOPSIS THALIANA HOMEOBOX GENE 8 (ATHB8), a marker of the procambial and preprocambial stages of vascular development, and on the anatomical criteria for recognizing vascular tissue pattern. The close correspondence between phyllotaxis and vascular pattern present in mature tissues arises at early stages of development, at least by the first plastochron of leaf primordium outgrowth. Current literature provides an integrative model in which local variation in auxin concentration regulates both primordium formation on the SAM and the first indications of a procambial prepattern in the position of primordium leaf trace as well as in the elaboration of leaf vein pattern. The prospects for extending this model to the development of the complex three-dimensional vascular architecture of the shoot are promising.

scholarly journals Expression of maize KNOTTED1 related homeobox genes in the shoot apical meristem predicts patterns of morphogenesis in the vegetative shoot

Development ◽  
1994 ◽  
Vol 120 (2) ◽  
pp. 405-413 ◽  
Author(s):  
D. Jackson ◽  
B. Veit ◽  
S. Hake
Keyword(s):  
Shoot Apical Meristem ◽  
Leaf Development ◽  
Apical Meristem ◽  
Expression Patterns ◽  
Homeobox Genes ◽  
Homeobox Gene ◽  
Vegetative Shoot ◽  
Lateral Organs ◽  
Floral Meristems ◽  
Shoot Meristems

In this paper we describe the expression patterns of a family of homeobox genes in maize and their relationship to organogenic domains in the vegetative shoot apical meristem. These genes are related by sequence to KNOTTED1, a gene characterized by dominant neomorphic mutations which perturb specific aspects of maize leaf development. Four members of this gene family are expressed in shoot meristems and the developing stem, but not in determinate lateral organs such as leaves or floral organs. The genes show distinct expression patterns in the vegetative shoot apical meristem that together predict the site of leaf initiation and the basal limit of the vegetative ‘phytomer’ or segmentation unit of the shoot. These genes are also expressed in the inflorescence and floral meristems, where their patterns of expression are more similar, and they are not expressed in root apical meristems. These findings are discussed in relation to other studies of shoot apical meristem organization as well as possible commonality of homeobox gene function in the animal and plant kingdoms.

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