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

scholarly journals Ontogenetic Changes in Auxin Biosynthesis and Distribution Determine the Organogenic Activity of the Shoot Apical Meristem in pin1 Mutants

2019 ◽  
Vol 20 (1) ◽  
pp. 180 ◽  
Author(s):  
Alicja Banasiak ◽  
Magdalena Biedroń ◽  
Alicja Dolzblasz ◽  
Mateusz Adam Berezowski
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Auxin Transport ◽  
Vascular System ◽  
Auxin Biosynthesis ◽  
Wild Type ◽  
Ontogenetic Changes ◽  
Auxin Distribution ◽  
Stem Development ◽  
Knockout Mutation

In the shoot apical meristem (SAM) of Arabidopsis, PIN1-dependent polar auxin transport (PAT) regulates two crucial developmental processes: organogenesis and vascular system formation. However, the knockout mutation in the PIN1 gene does not fully inhibit these two processes. Therefore, we investigated a potential source of auxin for organogenesis and vascularization during inflorescence stem development. We analyzed auxin distribution in wild-type (WT) and pin1 mutant plants using a refined protocol of auxin immunolocalization; auxin activity, with the response reporter pDR5:GFP; and expression of auxin biosynthesis genes YUC1 and YUC4. Our results revealed that regardless of the functionality of PIN1-mediated PAT, auxin is present in the SAM and vascular strands. In WT plants, auxin always accumulates in all cells of the SAM, whereas in pin1 mutants, its localization within the SAM changes ontogenetically and is related to changes in the structure of the vascular system, organogenic activity of SAM, and expression levels of YUC1 and YUC4 genes. Our findings indicate that the presence of auxin in the meristem of pin1 mutants is an outcome of at least two PIN1-independent mechanisms: acropetal auxin transport from differentiated tissues with the use of vascular strands and auxin biosynthesis within the SAM.

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 Toward a 3D model of phyllotaxis based on a biochemically plausible auxin-transport mechanism

2018 ◽  
Author(s):  
Félix P. Hartmann ◽  
Pierre Barbier de Reuille ◽  
Cris Kuhlemeier
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Auxin Transport ◽  
Vascular System ◽  
Three Dimensional ◽  
Integrative Approach ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Leaf Formation ◽  
Cell Layers

AbstractPolar auxin transport lies at the core of many self-organizing phenomena sustaining continuous plant organogenesis. In angiosperms, the shoot apical meristem is a potentially unique system in which the two main modes of auxin-driven patterning— convergence and canalization—co-occur in a coordinated manner and in a fully three-dimensional geometry. In the epidermal layer, convergence points form, from which auxin is canalized towards inner tissue. Each of these two patterning processes has been extensively investigated separately, but the integration of both in the shoot apical meristem remains poorly understood. We present here a first attempt of a three-dimensional model of auxin-driven patterning during phyllotaxis. We base our simulations on a biochemically plausible mechanism of auxin transport proposed by Cieslak et al. (2015) which generates both convergence and canalization patterns. We are able to reproduce most of the dynamics of PIN1 polarization in the meristem, and we explore how the epidermal and inner cell layers act in concert during phyllotaxis. In addition, we discuss the mechanism by which initiating veins connect to the already existing vascular system.Author summaryThe regularity of leaf arrangement around stems has long puzzled scientists. The key role played by the plant hormone auxin is now well established. On the surface of the tissue responsible for leaf formation, auxin accumulates at several points, from which new leaves eventually emerge. Auxin also guides the progression of new veins from the nascent leaves to the vascular system of the plant. Models of auxin transport have been developed to explain either auxin accumulation or auxin-driven venation. We propose the first three-dimensional model embracing both phenomena using a unifying mechanism of auxin transport. This integrative approach allows an assessment of our present knowledge on how auxin contributes to the early development of leaves. Our model reproduces many observations of auxin dynamics. It highlights how the inner and epidermal tissues act together to position new leaves. We also show that an additional, yet unknown, mechanism is required to attract new developing veins towards the main vasculature of the plant.

scholarly journals Alignment between PIN1 Polarity and Microtubule Orientation in the Shoot Apical Meristem Reveals a Tight Coupling between Morphogenesis and Auxin Transport

PLoS Biology ◽  
2010 ◽  
Vol 8 (10) ◽  
pp. e1000516 ◽  
Author(s):  
Marcus G. Heisler ◽  
Olivier Hamant ◽  
Pawel Krupinski ◽  
Magalie Uyttewaal ◽  
Carolyn Ohno ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Auxin Transport ◽  
Tight Coupling ◽  
Microtubule Orientation

scholarly journals Diversity of phyllotaxis in land plants in reference to the shoot apical meristem structure

2016 ◽  
Vol 85 (4) ◽  
Author(s):  
Edyta M. Gola ◽  
Alicja Banasiak
Keyword(s):  
Pattern Formation ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Land Plants ◽  
Phyllotactic Pattern ◽  
Lateral Organs ◽  
Spatio Temporal

Regularity and periodicity in the arrangements of organs in all groups of land plants raise questions about the mechanisms underlying phyllotactic pattern formation. The initiation of the lateral organs (leaves, flowers, etc.), and thus, their spatio-temporal positioning, occurs in the shoot apical meristem (SAM) and is related to the structure and organogenic activity of the meristem. In this review, we present some aspects of the diversity and stability of phyllotactic patterns in the major lineages of land plants, from bryophytes to angiosperms, in which SAM structures differ significantly. In addition, we discuss some of the possible mechanisms involved in the formation of the recurring arrangement of the lateral organs.

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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