1
|
Siciliano I, Lentz Grønlund A, Ševčíková H, Spadafora ND, Rafiei G, Francis D, Herbert RJ, Bitonti MB, Rogers HJ, Lipavská H. Expression of Arabidopsis WEE1 in tobacco induces unexpected morphological and developmental changes. Sci Rep 2019; 9:8695. [PMID: 31213651 PMCID: PMC6581958 DOI: 10.1038/s41598-019-45015-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 05/24/2019] [Indexed: 11/08/2022] Open
Abstract
WEE1 regulates the cell cycle by inactivating cyclin dependent protein kinases (CDKs) via phosphorylation. In yeast and animal cells, CDC25 phosphatase dephosphorylates the CDK releasing cells into mitosis, but in plants, its role is less clear. Expression of fission yeast CDC25 (Spcdc25) in tobacco results in small cell size, premature flowering and increased shoot morphogenetic capacity in culture. When Arath;WEE1 is over-expressed in Arabidopsis, root apical meristem cell size increases, and morphogenetic capacity of cultured hypocotyls is reduced. However expression of Arath;WEE1 in tobacco plants resulted in precocious flowering and increased shoot morphogenesis of stem explants, and in BY2 cultures cell size was reduced. This phenotype is similar to expression of Spcdc25 and is consistent with a dominant negative effect on WEE1 action. Consistent with this putative mechanism, WEE1 protein levels fell and CDKB levels rose prematurely, coinciding with early mitosis. The phenotype is not due to sense-mediated silencing of WEE1, as overall levels of WEE1 transcript were not reduced in BY2 lines expressing Arath;WEE1. However the pattern of native WEE1 transcript accumulation through the cell cycle was altered by Arath;WEE1 expression, suggesting feedback inhibition of native WEE1 transcription.
Collapse
Affiliation(s)
- Ilario Siciliano
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AT, UK
- School of Science and the Environment, University of Worcester, Henwick Grove, Worcester, WR2 6AJ, UK
| | - Anne Lentz Grønlund
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AT, UK
| | - Hana Ševčíková
- Department of Experimental Plant Biology, Charles University, Faculty of Science, Viničná 5, 128 43, Praha 2, Czech Republic
| | - Natasha D Spadafora
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AT, UK
- School of Science and the Environment, University of Worcester, Henwick Grove, Worcester, WR2 6AJ, UK
| | - Golnaz Rafiei
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AT, UK
| | - Dennis Francis
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AT, UK
| | - Robert J Herbert
- School of Science and the Environment, University of Worcester, Henwick Grove, Worcester, WR2 6AJ, UK
| | - M Beatrice Bitonti
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Cosenza, Italy
| | - Hilary J Rogers
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AT, UK.
| | - Helena Lipavská
- Department of Experimental Plant Biology, Charles University, Faculty of Science, Viničná 5, 128 43, Praha 2, Czech Republic
| |
Collapse
|
2
|
Elmaghrabi AM, Rogers HJ, Francis D, Ochatt S. Toward Unravelling the Genetic Determinism of the Acquisition of Salt and Osmotic Stress Tolerance Through In Vitro Selection in Medicago truncatula. Methods Mol Biol 2018; 1822:291-314. [PMID: 30043311 DOI: 10.1007/978-1-4939-8633-0_19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Changes in global climate and the nonstop increase in demographic pressure have provoked a stronger demand for agronomic resources at a time where land suitable for agriculture is becoming a rare commodity. They have also generated a number of abiotic stresses which exacerbate effects of diseases and pests and result in physiological and metabolic disorders that ultimately impact on yield when and where it is most needed. Therefore, a major scientific and agronomic challenge today is that of understanding and countering the impact of stress on yield. In this respect, in vitro biotechnology would be an efficient and feasible breeding alternative, particularly now that the genetic and genomic tools needed to unravel the mechanisms underlying the acquisition of tolerance to stress have become available. Legumes in general play a central role in a sustainable agriculture due to their capacity to symbiotically fix the atmospheric nitrogen, thereby reducing the need for fertilizers. They also produce grains that are rich in protein and thus are important as food and feed. However, they also suffer from abiotic stresses in general and osmotic stress and salinity in particular. This chapter provides a detailed overview of the methods employed for in vitro selection in the model legume Medicago truncatula for the generation of novel germplasm capable of resisting NaCl- and PEG-induced osmotic stress. We also address the understanding of the genetic determinism in the acquisition of stress resistance, which differs between NaCl and PEG. Thus, the expression of genes linked to growth (WEE1), in vitro embryogenesis (SERK), salt tolerance (SOS1) proline synthesis (P5CS), and ploidy level and cell cycle (CCS52 and WEE1) was upregulated under NaCl stress, while under PEG treatment the expression of MtWEE1 and MtCCS52 was significantly increased, but no significant differences were observed in the expression of genes MtSERK1 and MtP5CS, and MtSOS1 was downregulated. A number of morphological and physiological traits relevant to the acquisition of stress resistance were also assessed, and methods used to do so are also detailed.
Collapse
Affiliation(s)
- Adel M Elmaghrabi
- Biotechnology Research Center (BTRC), Tripoli, Libya
- School of Biosciences, Cardiff University, Cardiff, UK
| | | | | | - Sergio Ochatt
- Agroécologie, AgroSup Dijon, INRA, Univ. Bourgogne Franche-Comté, Dijon, France.
| |
Collapse
|
3
|
Elmaghrabi AM, Rogers HJ, Francis D, Ochatt SJ. PEG Induces High Expression of the Cell Cycle Checkpoint Gene WEE1 in Embryogenic Callus of Medicago truncatula: Potential Link between Cell Cycle Checkpoint Regulation and Osmotic Stress. FRONTIERS IN PLANT SCIENCE 2017; 8:1479. [PMID: 28928753 PMCID: PMC5591835 DOI: 10.3389/fpls.2017.01479] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/09/2017] [Indexed: 05/29/2023]
Abstract
Polyethylene glycol (PEG) can be used to mimic osmotic stress in plant tissue cultures to study mechanisms of tolerance. The aim of this experiment was to investigate the effects of PEG (M.W. 6000) on embryogenic callus of Medicago truncatula. Leaf explants were cultured on MS medium with 2 mg L-1 NAA and 0.5 mg L-1 BAP for 5 months. Then, calli were transferred to the same medium further supplemented with 10% (w/v) 6000 PEG for 6 months in order to study physiological and putative molecular markers of water stress. There were no significant differences in growth rate of callus or mitotic index ± PEG although embryogenic potential of PEG treated callus was morphologically enhanced. Cells were rounder on PEG medium and cell size, nuclear size and endoreduplication increased in response to the PEG treatment. Significant increases in soluble sugar and proline accumulation occurred under PEG treatment compared with the control. Significantly, high MtWEE1 and MtCCS52 expression resulted from 6 months of PEG treatment with no significant differences in MtSERK1 or MtP5CS expression but down regulation of MtSOS expression. The results are consistent in showing elevated expression of a cell cycle checkpoint gene, WEE1. It is likely that the cell cycle checkpoint surveillance machinery, that would include WEE1 expression, is ameliorating the effects of the stress imposed by PEG.
Collapse
Affiliation(s)
- Adel M. Elmaghrabi
- Biotechnology Research CenterTripoli, Libya
- School of Biosciences, Cardiff UniversityCardiff, United Kingdom
| | - Hilary J. Rogers
- School of Biosciences, Cardiff UniversityCardiff, United Kingdom
| | - Dennis Francis
- School of Biosciences, Cardiff UniversityCardiff, United Kingdom
| | - Sergio J. Ochatt
- Agroécologie, AgroSup Dijon, Institut National de la Recherche Agronomique (INRA), University of Bourgogne Franche-ComtéDijon, France
| |
Collapse
|
4
|
Schaller GE, Street IH, Kieber JJ. Cytokinin and the cell cycle. CURRENT OPINION IN PLANT BIOLOGY 2014; 21:7-15. [PMID: 24994531 DOI: 10.1016/j.pbi.2014.05.015] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 05/22/2014] [Accepted: 05/24/2014] [Indexed: 05/22/2023]
Abstract
The phytohormone cytokinin influences many aspects of plant growth and development, including a prominent role in the regulation of cell proliferation. How the cytokinin response pathway integrates into the machinery regulating progression through the cell cycle is only beginning to be appreciated. Cytokinin is generally considered to promote mitotic cell division in the shoot, but differentiation and transition to the endocycle in the root. Here we consider recent data on the inputs by which cytokinins positively and negatively regulate transitions through the cell cycle. Cytokinin positively regulates cell division and also serves a key role in establishing organization within shoot stem cell centers. Both auxin-dependent and auxin-independent mechanisms have been uncovered by which cytokinin stimulates the endocycle in roots. We conclude with a model that reconciles the opposing effects of cytokinin on shoot and root cell division.
Collapse
Affiliation(s)
- G Eric Schaller
- Dartmouth College, Department of Biological Sciences, Hanover, NH 03755, USA.
| | - Ian H Street
- Dartmouth College, Department of Biological Sciences, Hanover, NH 03755, USA
| | - Joseph J Kieber
- University of North Carolina, Biology Department, Chapel Hill, NC 27599, USA.
| |
Collapse
|
5
|
Mohd-Radzman NA, Djordjevic MA, Imin N. Nitrogen modulation of legume root architecture signaling pathways involves phytohormones and small regulatory molecules. FRONTIERS IN PLANT SCIENCE 2013; 4:385. [PMID: 24098303 PMCID: PMC3787543 DOI: 10.3389/fpls.2013.00385] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 09/11/2013] [Indexed: 05/20/2023]
Abstract
Nitrogen, particularly nitrate is an important yield determinant for crops. However, current agricultural practice with excessive fertilizer usage has detrimental effects on the environment. Therefore, legumes have been suggested as a sustainable alternative for replenishing soil nitrogen. Legumes can uniquely form nitrogen-fixing nodules through symbiotic interaction with specialized soil bacteria. Legumes possess a highly plastic root system which modulates its architecture according to the nitrogen availability in the soil. Understanding how legumes regulate root development in response to nitrogen availability is an important step to improving root architecture. The nitrogen-mediated root development pathway starts with sensing soil nitrogen level followed by subsequent signal transduction pathways involving phytohormones, microRNAs and regulatory peptides that collectively modulate the growth and shape of the root system. This review focuses on the current understanding of nitrogen-mediated legume root architecture including local and systemic regulations by different N-sources and the modulations by phytohormones and small regulatory molecules.
Collapse
Affiliation(s)
| | | | - Nijat Imin
- *Correspondence: Nijat Imin, Division of Plant Sciences, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Linnaeus Building 134, Linnaeus Way, Canberra, ACT 0200, Australia e-mail:
| |
Collapse
|