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.

Comparative analysis of axillary and floral meristem development

2005 ◽  
Vol 83 (4) ◽  
pp. 343-349 ◽  
Author(s):  
Vojislava Grbić
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Reproductive Development ◽  
Vegetative Development ◽  
Initial Development ◽  
Meristem Development ◽  
Axillary Meristems ◽  
Floral Meristems ◽  
Lateral Suppressor ◽  
Shoot Meristems

Axillary and floral meristems are shoot meristems that initiate postembryonically. In Arabidopsis, axillary meristems give rise to branches during vegetative development while floral meristems give rise to flowers during reproductive development. This review compares the development of these meristems from their initiation at the shoot apical meristem up to the establishment of their specific developmental fates. Axillary and floral meristems originate from lateral primordia that form at flanks of the shoot apical meristem. Initial development of vegetative and reproductive primordia are similar, resulting in the formation of a morphologically defined primordium partitioned into adaxial and abaxial domains. The adaxial primordial domain is competent to form a meristem, while the abaxial domain correlates with the formation of a leaf. This review proposes that all primordia partition into domains competent to form the meristem and the leaf. According to this model, a vegetative primordium develops as leaf-bias while a reproductive primordium develops as meristem-bias.Key words: SHOOTMERISTEMLESS, LATERAL SUPPRESSOR, AINTEGUMENTA, adaxial primordial domain, abaxial primordial domain, shoot morphogenesis.

scholarly journals Mechanical stress contributes to the expression of the STM homeobox gene in Arabidopsis shoot meristems

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Benoît Landrein ◽  
Annamaria Kiss ◽  
Massimiliano Sassi ◽  
Aurélie Chauvet ◽  
Pradeep Das ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Homeobox Gene ◽  
Master Regulator ◽  
Cell Identity ◽  
Auxin Distribution ◽  
Mechanical Signals ◽  
Shoot Meristems

The role of mechanical signals in cell identity determination remains poorly explored in tissues. Furthermore, because mechanical stress is widespread, mechanical signals are difficult to uncouple from biochemical-based transduction pathways. Here we focus on the homeobox gene SHOOT MERISTEMLESS (STM), a master regulator and marker of meristematic identity in Arabidopsis. We found that STM expression is quantitatively correlated to curvature in the saddle-shaped boundary domain of the shoot apical meristem. As tissue folding reflects the presence of mechanical stress, we test and demonstrate that STM expression is induced after micromechanical perturbations. We also show that STM expression in the boundary domain is required for organ separation. While STM expression correlates with auxin depletion in this domain, auxin distribution and STM expression can also be uncoupled. STM expression and boundary identity are thus strengthened through a synergy between auxin depletion and an auxin-independent mechanotransduction pathway at the shoot apical meristem.

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 HANABA TARANUregulates the shoot apical meristem and leaf development in cucumber (Cucumis sativusL.)

2015 ◽  
Vol 66 (22) ◽  
pp. 7075-7087 ◽  
Author(s):  
Lian Ding ◽  
Shuangshuang Yan ◽  
Li Jiang ◽  
Meiling Liu ◽  
Juan Zhang ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Leaf Development ◽  
Apical Meristem

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 OsPNH1regulates leaf development and maintenance of the shoot apical meristem in rice

2002 ◽  
Vol 30 (2) ◽  
pp. 189-201 ◽  
Author(s):  
Asuka Nishimura ◽  
Momoyo Ito ◽  
Noriko Kamiya ◽  
Yutaka Sato ◽  
Makoto Matsuoka
Keyword(s):  
Shoot Apical Meristem ◽  
Leaf Development ◽  
Apical Meristem

scholarly journals Erythroid-restricted expression of homeobox genes of the human HOX 2 locus

Blood ◽  
1991 ◽  
Vol 78 (9) ◽  
pp. 2248-2252 ◽  
Author(s):  
CH Mathews ◽  
K Detmer ◽  
E Boncinelli ◽  
HJ Lawrence ◽  
C Largman
Keyword(s):  
Cell Lines ◽  
Expression Patterns ◽  
Homeobox Genes ◽  
Homeobox Gene ◽  
Leukemic Cell ◽  
Hematopoietic Cell ◽  
Erythroid Cell ◽  
Small Series ◽  
Hematopoietic Cell Lines ◽  
In Cells

We have previously reported that certain members of the HOX 1 and HOX 2 clusters of class 1 homeobox-containing genes showed lineage-restricted patterns of expression in a small series of human hematopoietic cell lines. We now report on the expression patterns of the entire HOX 2 cluster, consisting of nine homeobox genes, in a broad survey of leukemic cell lines of different phenotypes. The most striking observation is that all but one of the HOX 2 genes are consistently expressed in cells with erythroid character and/or potential, but, with rare exception, not in cells with myelomonocytic or T- or B-lymphoid phenotype. By contrast, several genes of the HOX 1 and 3 loci are not expressed in erythroid lines. Within erythroid cell lines, many of the HOX 2 genes are expressed as multiple transcripts. Expression of some HOX 2 genes is detectable in normal human marrow. These data show that in human hematopoietic cell lines HOX 2 homeobox gene expression is largely restricted to cells of erythroid phenotype and suggest that these genes play a role in erythropoiesis.

scholarly journals New Symptoms Identified in Phytoplasma-Infected Plants Reveal Extra Stages of Pathogen-Induced Meristem Fate-Derailment

2019 ◽  
Vol 32 (10) ◽  
pp. 1314-1323 ◽  
Author(s):  
Wei Wei ◽  
Robert E. Davis ◽  
Gary R. Bauchan ◽  
Yan Zhao
Keyword(s):  
Seed Production ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Flowering Plants ◽  
Multistage Process ◽  
Inflorescence Meristem ◽  
Sieve Cells ◽  
Specific Stage ◽  
Transition Research ◽  
Floral Meristems

In flowering plants, the transition of a shoot apical meristem from vegetative to reproductive destiny is a graduated, multistage process that involves sequential conversion of the vegetative meristem to an inflorescence meristem, initiation of floral meristems, emergence of flower organ primordia, and formation of floral organs. This orderly process can be derailed by phytoplasma, a bacterium that parasitizes phloem sieve cells. In a previous study, we showed that phytoplasma-induced malformation of flowers reflects stage-specific derailment of shoot apical meristems from their genetically preprogrammed reproductive destiny. Our current study unveiled new symptoms of abnormal morphogenesis, pointing to derailment of meristem transition at additional stages previously unidentified. We also found that the fate of developing meristems may be derailed even after normal termination of the floral meristem and onset of seed production. Although previous reports by others have indicated that different symptoms may be induced by different phytoplasmal effectors, the phenomenon observed in our experiment raises interesting questions as to (i) whether effectors can act at specific stages of meristem transition and (ii) whether specific floral abnormalities are attributable to meristem fate-derailment events triggered by different effectors that each act at a specific stage in meristem transition. Research addressing such questions may lead to discoveries of an array of phytoplasmal effectors.

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