Drosophila Eye as a Model to Study Regulation of Growth Control: The Discovery of Size Control Pathways

2013 ◽  
pp. 229-270
Author(s):  
Shilpi Verghese ◽  
Indrayani Waghmare ◽  
Shree Ram Singh ◽  
Madhuri Kango-Singh
Keyword(s):  
Growth Control ◽  
Size Control ◽  
Drosophila Eye ◽  
Regulation Of Growth

scholarly journals Determination of organ size: a need to focus on growth rate, not size

2020 ◽  
Vol 64 (4-5-6) ◽  
pp. 299-318
Author(s):  
Carmen M.A. Coelho
Keyword(s):  
Control Mechanism ◽  
Growth Control ◽  
Size Control ◽  
Organ Size ◽  
Cell Competition ◽  
The Past ◽  
Mechanistic Basis ◽  
Regulation Of Growth ◽  
Correct Size

The regulation of growth and the determination of organ-size in animals is an area of research that has received much attention during the past two and a half decades. Classic regeneration and cell-competition studies performed during the last century suggested that for size to be determined, organ-size is sensed and this sense of size feeds back into the growth control mechanism such that growth stops at the “correct” size. Recent work using Drosophila imaginal discs as a system has provided a particularly detailed cellular and molecular understanding of growth. Yet, a clear mechanistic basis for size-sensing has not emerged. I re-examine these studies from a different perspective and ask whether there is scope for alternate modes of size control in which size does not need to be sensed.

Abstract 2193: WT1 mediated regulation of growth control genes in leukemia

2012 ◽  
Author(s):  
Sony Pandey ◽  
Mustafa Moazam ◽  
Kurtis Eisermann ◽  
Steven Kuerbitz ◽  
Gail Fraizer
Keyword(s):  
Growth Control ◽  
Regulation Of Growth

scholarly journals Growth Regulation of Mexican Sage and ‘Homestead Purple’ Verbena During Greenhouse and Nursery Production

2000 ◽  
Vol 18 (3) ◽  
pp. 166-170
Author(s):  
S. E. Burnett ◽  
G. J. Keever ◽  
J. R. Kessler ◽  
C.H. Gilliam
Keyword(s):  
Growth Regulation ◽  
Shoot Growth ◽  
Growth Control ◽  
Size Control ◽  
Plant Size ◽  
Effective Rate ◽  
Growth Retardants ◽  
Growth Reduction ◽  
Affected Plant ◽  
Nursery Production

Abstract Salvia leucantha (Mexican sage) and Verbena canadensis ‘Homestead Purple’ were treated with the plant growth retardants (PGRs), Cutless, Sumagic, B-Nine/Cycocel tank mixes, or Pistill under both greenhouse and nursery conditions. Increasing rates of all PGRs applied to both species reduced plant size in the greenhouse for 6 weeks after treatment (WAT). Growth reduction of Mexican sage with the most effective rate (providing greatest growth control) of each PGR over this period averaged 11% with Cutless, 15% with Sumagic, 23% with B-Nine/Cycocel tank mixes, and 25% with Pistill. For verbena, size control with the most effective rate of each PGR averaged 15% with Cutless, 18% with Sumagic, 27% with B-Nine/Cycocel tank mixes, and 29% with Pistill. After transplanting greenhouse-grown plants into outdoor ground beds, only Mexican sage treated with B-Nine/Cycocel were significantly smaller 4 weeks after planting (WAP). Greenhouse-grown verbena treated with Sumagic, B-Nine/Cycocel tank mixes, and Pistill and planted in the landscape were 15—23%, 18–25%, and 0–20% smaller, respectively, than control plants at 2 WAP, but by 4 WAP, all PGR-treated verbena were similar in size to control plants. Under nursery conditions, Cutless and B-Nine/Cycocel tank mix reduced Mexican sage size up to 4 WAT. None of the PGRs affected plant size at 6 WAT. The most effective rate of each PGR (averaged over the duration that a PGR was significant) suppressed shoot growth 16% for Cutless, 12% with Sumagic, 20% for B-Nine/Cycocel tank mixes, and 29% for Pistill. For verbena only, Sumagic suppressed growth up to 10% at 2 WAT, and no PGR effectively controlled growth under nursery conditions 4 WAT.

scholarly journals Xyloglucan Remodeling Defines Auxin-Dependent Differential Tissue Expansion in Plants

2021 ◽  
Vol 22 (17) ◽  
pp. 9222 ◽  
Author(s):  
Silvia Melina Velasquez ◽  
Xiaoyuan Guo ◽  
Marçal Gallemi ◽  
Bibek Aryal ◽  
Peter Venhuizen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Growth Control ◽  
Size Control ◽  
Tissue Expansion ◽  
Major Type ◽  
Hypocotyl Growth ◽  
Differential Growth ◽  
Rigid Cell Wall ◽  
Molecular Complexity ◽  
Genetic Interference

Size control is a fundamental question in biology, showing incremental complexity in plants, whose cells possess a rigid cell wall. The phytohormone auxin is a vital growth regulator with central importance for differential growth control. Our results indicate that auxin-reliant growth programs affect the molecular complexity of xyloglucans, the major type of cell wall hemicellulose in eudicots. Auxin-dependent induction and repression of growth coincide with reduced and enhanced molecular complexity of xyloglucans, respectively. In agreement with a proposed function in growth control, genetic interference with xyloglucan side decorations distinctly modulates auxin-dependent differential growth rates. Our work proposes that auxin-dependent growth programs have a spatially defined effect on xyloglucan’s molecular structure, which in turn affects cell wall mechanics and specifies differential, gravitropic hypocotyl growth.

scholarly journals Bootstrapping and Pinning down the Root Meristem; the Auxin–PLT–ARR Network Unites Robustness and Sensitivity in Meristem Growth Control

2021 ◽  
Vol 22 (9) ◽  
pp. 4731
Author(s):  
Jacob P. Rutten ◽  
Kirsten H. Ten Tusscher
Keyword(s):  
Regulatory Network ◽  
Root Meristem ◽  
Response Regulator ◽  
Plant Root ◽  
Growth Control ◽  
Size Control ◽  
Functional Constraints ◽  
Interaction Domain ◽  
Meristem Size ◽  
Embryonic Root

After germination, the meristem of the embryonic plant root becomes activated, expands in size and subsequently stabilizes to support post-embryonic root growth. The plant hormones auxin and cytokinin, together with master transcription factors of the PLETHORA (PLT) family have been shown to form a regulatory network that governs the patterning of this root meristem. Still, which functional constraints contributed to shaping the dynamics and architecture of this network, has largely remained unanswered. Using a combination of modeling approaches we reveal how the interplay between auxin and PLTs enables meristem activation in response to above-threshold stimulation, while its embedding in a PIN-mediated auxin reflux loop ensures localized PLT transcription and thereby, a finite meristem size. We furthermore demonstrate how this constrained PLT transcriptional domain enables independent control of meristem size and division rates, further supporting a division of labor between auxin and PLT. We subsequently reveal how the weaker auxin antagonism of the earlier active Arabidopsis response regulator 12 (ARR12) may arise from the absence of a DELLA protein interaction domain. Our model indicates that this reduced strength is essential to prevent collapse in the early stages of meristem expansion while at later stages the enhanced strength of Arabidopsis response regulator 1 (ARR1) is required for sufficient meristem size control. Summarizing, our work indicates that functional constraints significantly contribute to shaping the auxin–cytokinin–PLT regulatory network.

scholarly journals Xyloglucan remodelling defines differential tissue expansion in plants

2019 ◽  
Author(s):  
Silvia Melina Velasquez ◽  
Xiaoyuan Guo ◽  
Marçal Gallemi ◽  
Bibek Aryal ◽  
Peter Venhuizen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Growth Control ◽  
Size Control ◽  
Tissue Expansion ◽  
Central Importance ◽  
Hypocotyl Growth ◽  
Differential Growth ◽  
Rigid Cell Wall ◽  
Genetic Interference ◽  
Cell Wall Mechanics

Size control is a fundamental question in biology, showing incremental complexity in case of plants whose cells possess a rigid cell wall. The phytohormone auxin is a vital growth regulator with central importance for differential growth control. Here we show that growth inducing and repressing auxin conditions correlate with reduced and enhanced complexity of extracellular xyloglucans, respectively. In agreement, genetic interference with xyloglucan complexity distinctly modulates auxin-dependent differential growth rates. Our work proposes that an auxin-dependent, spatially defined effect on xyloglucan structure and its effect on cell wall mechanics specify differential, gravitropic hypocotyl growth.

Cell Size Control in Plants

2019 ◽  
Vol 53 (1) ◽  
pp. 45-65 ◽  
Author(s):  
Marco D'Ario ◽  
Robert Sablowski
Keyword(s):  
Cell Size ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Growth Control ◽  
Size Control ◽  
Yeast Cells ◽  
Shoot Meristem ◽  
Functional Consequences ◽  
Cell Size Control ◽  
Size Heterogeneity

The genetic control of the characteristic cell sizes of different species and tissues is a long-standing enigma. Plants are convenient for studying this question in a multicellular context, as their cells do not move and are easily tracked and measured from organ initiation in the meristems to subsequent morphogenesis and differentiation. In this article, we discuss cell size control in plants compared with other organisms. As seen from yeast cells to mammalian cells, size homeostasis is maintained cell autonomously in the shoot meristem. In developing organs, vacuolization contributes to cell size heterogeneity and may resolve conflicts between growth control at the cellular and organ levels. Molecular mechanisms for cell size control have implications for how cell size responds to changes in ploidy, which are particularly important in plant development and evolution. We also discuss comparatively the functional consequences of cell size and their potential repercussions at higher scales, including genome evolution.

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