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

Elmaghrabi, Adel M.; Rogers, Hilary J.; Francis, Dennis; Ochatt, Sergio

doi:10.3389/fpls.2017.01479

Cited by 37 publications

(27 citation statements)

References 77 publications

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“…Nonetheless, most studies using both methods agree on a high level of equivalency among them [ 29 , 30 , 31 ]. When considering the different type of material used, a recent study showed the occurrence of similar mitotic indexes and gene expression profiles in M. truncatula leaves grown in a greenhouse and calli-cultured in vitro [ 32 ]. Likewise, our work using M. truncatula overexpressing the MtTdp2α gene revealed a high degree of similarity in the expression pattern of several DNA repair genes in both plants grown in vitro and cell suspension cultures [ 10 , 33 ].…”

Section: Discussionmentioning

confidence: 99%

The Tyrosyl-DNA Phosphodiesterase 1β (Tdp1β) Gene Discloses an Early Response to Abiotic Stresses

Sabatini¹,

Pagano²,

Araújo

et al. 2017

Genes

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Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is involved in DNA repair pathways as it mends the topoisomerase I—DNA covalent complexes. In plants, a small Tdp1 gene family, composed by Tdp1α and Tdp1β genes, was identified, but the roles of these genes in abiotic stress responses are not fully understood. To investigate their specific stress response patterns, the present study made use of bioinformatic and molecular tools to look into the Tdp1β gene function, so far described only in the plant kingdom, and compare it with Tdp1α gene coding for the canonical, highly conserved α isoform. The expression profiles of Tdp1α and Tdp1β genes were examined under abiotic stress conditions (cold, heat, high osmolarity, salt, and UV-B) in two model species, Arabidopsis thaliana and Medicago truncatula. The two isoforms of topoisomerase I (TOP1α and TOP1β) were also taken into consideration in view of their known roles in DNA metabolism and cell proliferation. Data relative to gene expression in Arabidopsis were retrieved from the AtGenExpress microarray dataset, while quantitative Real-Time PCR was carried out to evaluate the stress response in M. truncatula cell cultures. These analyses revealed that Tdp1β gene expression was enhanced during the first hour of treatment, whereas Tdp1α enhanced expression succeeded at subsequent timepoints. In agreement with the gene-specific responses to abiotic stress conditions, the promoter regions of Tdp1α and Tdp1β genes are well equipped with stress-related cis-elements. An in-depth bioinformatic characterization of the HIRAN motif, a distinctive feature of the Tdp1β protein, showed its wide distribution in chromatin remodeling and DNA repair proteins. The reported data suggests that Tdp1β functions in the early response to abiotic stresses.

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Section: Discussionmentioning

confidence: 99%

The Tyrosyl-DNA Phosphodiesterase 1β (Tdp1β) Gene Discloses an Early Response to Abiotic Stresses

Sabatini¹,

Pagano²,

Araújo

et al. 2017

Genes

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“…Consistently, the higher ploidy of M. glaucescens and M. paucispinus cortex cells can be related to the presence of aquifer parenchyma, which is formed by large cells with elevated ploidy and capacity for storing large volumes of water ( De Rocher et al, 1990 ). Indeed, endoreduplication has been associated with adaptation to saline and water stress conditions, extremely dry conditions and elevated temperatures ( Lema-Rumińska, 2011 ; Elmaghrabi et al, 2013 ; Scholes and Paige, 2015 ; Elmaghrabi et al, 2017 ; Elmaghrabi et al, 2019 ).…”

Section: Discussionmentioning

confidence: 99%

Anatomy, Flow Cytometry, and X-Ray Tomography Reveal Tissue Organization and Ploidy Distribution in Long-Term In Vitro Cultures of Melocactus Species

et al. 2020

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Cacti have a highly specialized stem that enables survival during extended dry periods. Despite the ornamental value of cacti and the fact that stems represent the main source of explants in tissue culture, there are no studies on their morpho-anatomical and cytological characteristics in Melocactus . The present study seeks to address the occurrence of cells with mixed ploidy level in cacti tissues. Specifically, we aim to understand how Melocactus stem tissue is organized, how mixoploidy is distributed when present, and whether detected patterns of ploidy change after long periods of in vitro culture. To analyze tissue organization, Melocactus glaucescens and Melocactus paucispinus plants that had been germinated and cultivated in vitro were analyzed for stem structure using toluidine blue, Xylidine Ponceau, Periodic Acid Schiff, ruthenium red, and acid floroglucin. To investigate patterns of ploidy, apical, medial, and basal zones of the stem, as well as, periphery, cortex, and stele (vascular tissue and pith) regions of the stem and root apexes from four- and ten-year old cultured in vitro were analyzed by flow cytometry. X-ray micro-computed tomography (XRµCT) was performed with fragments of stems from both species. The scarcity of support elements ( i.e. , sclereids and fibers) indicates that epidermis, hypodermis, and wide-band tracheids present in cortical vascular bundles and stele, as well as water stored in aquifer parenchyma cells along the cortex, provide mechanical support to the stem. Parenchyma cells increase in volume with a four-fold increase in ploidy. M. glaucescens and M. paucispinus exhibit the same pattern of cell ploidy irrespective of topophysical region or age, but there is a marked difference in ploidy between the stem periphery (epidermis and hypodermis), cortex, stele, and roots. Mixoploidy in Melocactus is not related to the age of the culture, but is a developmental trait, whereby endocycles promote cell differentiation to accumulate valuable water.

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“…The different mechanisms are evident as exemplified by the different patterns of expression of several genes with known functions in DNA damage response between the two systems. However, it cannot be ruled out that some of these divergences might be due to the use of different systems (calli vs. plants) or genomic variability; though, a recent study showed the occurrence of similar gene expression profiles in in vitro grown calli and M. truncatula plantlets [ 47 ]. Hence, the presented results are indicative of the use of hTdp1 inhibitor as a tool for future studies aiming to decipher the peculiar roles of the plant Tdp1 genes.…”

Section: Discussionmentioning

confidence: 99%

The Human Tyrosyl-DNA Phosphodiesterase 1 (hTdp1) Inhibitor NSC120686 as an Exploratory Tool to Investigate Plant Tdp1 Genes

Macovei

Pagano

Sabatini

et al. 2018

Genes

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The hTdp1 (human tyrosyl-DNA phosphodiesterase 1) inhibitor NSC120686 has been used, along with topoisomerase inhibitors, as a pharmacophoric model to restrain the Tdp1 activity as part of a synergistic treatment for cancer. While this compound has an end-point application in medical research, in plants, its application has not been considered so far. The originality of our study consists in the use of hTdp1 inhibitor in Medicago truncatula cells, which, unlike human cells, contain two Tdp1 genes. Hence, the purpose of this study was to test the hTdp1 inhibitor NSC120686 as an exploratory tool to investigate the plant Tdp1 genes, since their characterization is still in incipient phases. To do so, M. truncatula calli were exposed to increasing (75, 150, 300 μM) concentrations of NSC120686. The levels of cell mortality and DNA damage, measured via diffusion assay and comet assay, respectively, were significantly increased when the highest doses were used, indicative of a cytotoxic and genotoxic threshold. In addition, the NSC120686-treated calli and untreated MtTdp1α-depleted calli shared a similar response in terms of programmed cell death (PCD)/necrosis and DNA damage. Interestingly, the expression profiles of MtTdp1α and MtTdp1β genes were differently affected by the NSC120686 treatment, as MtTdp1α was upregulated while MtTdp1β was downregulated. The NSC120686 treatment affected not only the MtTdp1 genes but also other genes with roles in alternative DNA repair pathways. Since the expression patterns of these genes were different than what was observed in the MtTdp1α-depleted plants, it could be hypothesized that the NSC120686 treatment exerts a different influence compared to that resulting from the lack of the MtTdp1α gene function.

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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

Cited by 37 publications

References 77 publications

The Tyrosyl-DNA Phosphodiesterase 1β (Tdp1β) Gene Discloses an Early Response to Abiotic Stresses

The Tyrosyl-DNA Phosphodiesterase 1β (Tdp1β) Gene Discloses an Early Response to Abiotic Stresses

Anatomy, Flow Cytometry, and X-Ray Tomography Reveal Tissue Organization and Ploidy Distribution in Long-Term In Vitro Cultures of Melocactus Species

The Human Tyrosyl-DNA Phosphodiesterase 1 (hTdp1) Inhibitor NSC120686 as an Exploratory Tool to Investigate Plant Tdp1 Genes

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