@article{2-s2.0-85176574335,

title = {The improvement of the in vitro plant regeneration in barley with the epigenetic modifier of histone acetylation, trichostatin A},

author = { K. Nowak and B. Wójcikowska and M. Gajecka and A. Elżbieciak and J. Morończyk and A.M. Wójcik and P. Żemła and S. Citerne and A. Kiwior-Wesołowska and J. Zbieszczyk and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85176574335&doi=10.1007%2fs13353-023-00800-9&partnerID=40&md5=aba91f468acebb6e7ac6030f68dc49f7},

doi = {10.1007/s13353-023-00800-9},

issn = {12341983},

year  = {2024},

date = {2024-01-01},

journal = {Journal of Applied Genetics},

volume = {65},

number = {1},

pages = {13-30},

publisher = {Springer Science and Business Media Deutschland GmbH},

abstract = {Genotype-limited plant regeneration is one of the main obstacles to the broader use of genetic transformation in barley breeding. Thus, developing new approaches that might improve responses of in vitro recalcitrant genotypes remains at the center of barley biotechnology. Here, we analyzed different barley genotypes, including “Golden Promise,” a genotype commonly used in the genetic transformation, and four malting barley cultivars of poor regenerative potential. The expression of hormone-related transcription factor (TF) genes with documented roles in plant regeneration was analyzed in genotypes with various plant-regenerating capacities. The results indicated differential expression of auxin-related TF genes between the barley genotypes in both the explants and the derived cultures. In support of the role of auxin in barley regeneration, distinct differences in the accumulation of free and oxidized auxin were observed in explants and explant-derived callus cultures of barley genotypes. Following the assumption that modifying gene expression might improve plant regeneration in barley, we treated the barley explants with trichostatin A (TSA), which affects histone acetylation. The effects of TSA were genotype-dependent as TSA treatment improved plant regeneration in two barley cultivars. TSA-induced changes in plant regeneration were associated with the increased expression of auxin biosynthesis-involved TFs. The study demonstrated that explant treatment with chromatin modifiers such as TSA might provide a new and effective epigenetic approach to improving plant regeneration in recalcitrant barley genotypes. © 2023, The Author(s).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85179671840,

title = {Game of thrones among AUXIN RESPONSE FACTORs - over 30 years of MONOPTEROS research},

author = { B. Wójcikowska and S. Belaidi and H.S. Robert},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85179671840&doi=10.1093%2fjxb%2ferad272&partnerID=40&md5=6230436286014535cde39411fbfd3480},

doi = {10.1093/jxb/erad272},

issn = {00220957},

year  = {2023},

date = {2023-01-01},

journal = {Journal of Experimental Botany},

volume = {74},

number = {22},

pages = {6904-6921},

publisher = {Oxford University Press},

abstract = {For many years, research has been carried out with the aim of understanding the mechanism of auxin action, its biosynthesis, catabolism, perception, and transport. One central interest is the auxin-dependent gene expression regulation mechanism involving AUXIN RESPONSE FACTOR (ARF) transcription factors and their repressors, the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins. Numerous studies have been focused on MONOPTEROS (MP)/ARF5, an activator of auxin-dependent gene expression with a crucial impact on plant development. This review summarizes over 30 years of research on MP/ARF5. We indicate the available analytical tools to study MP/ARF5 and point out the known mechanism of MP/ARF5-dependent regulation of gene expression during various developmental processes, namely embryogenesis, leaf formation, vascularization, and shoot and root meristem formation. However, many questions remain about the auxin dose-dependent regulation of gene transcription by MP/ARF5 and its isoforms in plant cells, the composition of the MP/ARF5 protein complex, and, finally, all the genes under its direct control. In addition, information on post-translational modifications of MP/ARF5 protein is marginal, and knowledge about their consequences on MP/ARF5 function is limited. Moreover, the epigenetic factors and other regulators that act upstream of MP/ARF5 are poorly understood. Their identification will be a challenge in the coming years. © 2023 The Author(s). Published by Oxford University Press on behalf of the Society for Experimental Biology.},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85126018562,

title = {Insights into the Histone Acetylation-Mediated Regulation of the Transcription Factor Genes That Control the Embryogenic Transition in the Somatic Cells of Arabidopsis},

author = { J. Morończyk and A.J. Brąszewska-Zalewska and B. Wójcikowska and K. Chwiałkowska and K. Nowak and A.M. Wójcik and M. Kwaśniewski and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85126018562&doi=10.3390%2fcells11050863&partnerID=40&md5=b2d79e5ee5e0aad3ef0629dc7393c322},

doi = {10.3390/cells11050863},

issn = {20734409},

year  = {2022},

date = {2022-01-01},

journal = {Cells},

volume = {11},

number = {5},

publisher = {MDPI},

abstract = {Somatic embryogenesis (SE), which is a process that involves the in vitro-induced embryo-genic reprogramming of plant somatic cells, requires dynamic changes in the cell transcriptome. These changes are fine-tuned by many genetic and epigenetic factors, including posttranslational histone modifications such as histone acetylation. Antagonistically acting enzymes, histone acetyltransferases (HATs) and deacetylases (HDACs), which control histone acetylation in many developmental pro-cesses, are believed to control SE. However, the function of specific HAT/HDACs and the genes that are subjected to histone acetylation-mediated regulation during SE have yet to be revealed. Here, we present the global and gene-specific changes in histone acetylation in Arabidopsis explants that are undergoing SE. In the TSA (trichostatin A)-induced SE, we demonstrate that H3 and H4 acetylation might control the expression of the critical transcription factor (TF) genes of a vital role in SE, including LEC1, LEC2 (LEAFY COTYLEDON 1; 2), FUS3 (FUSCA 3) and MYB118 (MYB DOMAIN PROTEIN 118). Within the HATs and HDACs, which mainly positively regulate SE, we identified HDA19 as negatively affecting SE by regulating LEC1, LEC2 and BBM. Finally, we provide some evidence on the role of HDA19 in the histone acetylation-mediated regulation of LEC2 during SE. Our results reveal an essential function of histone acetylation in the epigenetic mechanisms that control the TF genes that play critical roles in the embryogenic reprogramming of plant somatic cells. The results implicate the complexity of Hac-related gene regulation in embryogenic induction and point to differences in the regulatory mechanisms that are involved in auxin-and TSA-induced SE. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.},

note = {10},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85082731253,

title = {Epigenetic regulation of auxin-induced somatic embryogenesis in plants},

author = { B. Wójcikowska and A.M. Wójcik and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85082731253&doi=10.3390%2fijms21072307&partnerID=40&md5=ab1fc9ddb6bd291d0c7e177c7d8313d0},

doi = {10.3390/ijms21072307},

issn = {16616596},

year  = {2020},

date = {2020-01-01},

journal = {International Journal of Molecular Sciences},

volume = {21},

number = {7},

publisher = {MDPI AG},

abstract = {Somatic embryogenesis (SE) that is induced in plant explants in response to auxin treatment is closely associated with an extensive genetic reprogramming of the cell transcriptome. The significant modulation of the gene transcription profiles during SE induction results from the epigenetic factors that fine-tune the gene expression towards embryogenic development. Among these factors, microRNA molecules (miRNAs) contribute to the post-transcriptional regulation of gene expression. In the past few years, several miRNAs that regulate the SE-involved transcription factors (TFs) have been identified, and most of them were involved in the auxin-related processes, including auxin metabolism and signaling. In addition to miRNAs, chemical modifications of DNA and chromatin, in particular the methylation of DNA and histones and histone acetylation, have been shown to shape the SE transcriptomes. In response to auxin, these epigenetic modifications regulate the chromatin structure, and hence essentially contribute to the control of gene expression during SE induction. In this paper, we describe the current state of knowledge with regard to the SE epigenome. The complex interactions within and between the epigenetic factors, the key SE TFs that have been revealed, and the relationships between the SE epigenome and auxin-related processes such as auxin perception, metabolism, and signaling are highlighted. © 2020, MDPI AG. All rights reserved.},

note = {30},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85079636159,

title = {Current perspectives on the auxin-mediated genetic network that controls the induction of somatic embryogenesis in plants},

author = { A.M. Wójcik and B. Wójcikowska and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85079636159&doi=10.3390%2fijms21041333&partnerID=40&md5=280c4b8858da9a30c603d1009ec24500},

doi = {10.3390/ijms21041333},

issn = {16616596},

year  = {2020},

date = {2020-01-01},

journal = {International Journal of Molecular Sciences},

volume = {21},

number = {4},

publisher = {MDPI AG},

abstract = {Auxin contributes to almost every aspect of plant development and metabolism as well as the transport and signalling of auxin-shaped plant growth and morphogenesis in response to endo-and exogenous signals including stress conditions. Consistently with the common belief that auxin is a central trigger of developmental changes in plants, the auxin treatment of explants was reported to be an indispensable inducer of somatic embryogenesis (SE) in a large number of plant species. Treating in vitro-cultured tissue with auxins (primarily 2;4-dichlorophenoxyacetic acid; which is a synthetic auxin-like plant growth regulator) results in the extensive reprogramming of the somatic cell transcriptome, which involves the modulation of numerous SE-associated transcription factor genes (TFs). A number of SE-modulated TFs that control auxin metabolism and signalling have been identified, and conversely, the regulators of the auxin-signalling pathway seem to control the SE-involved TFs. In turn, the different expression of the genes encoding the core components of the auxin-signalling pathway, the AUXIN/INDOLE-3-ACETIC ACIDs (Aux/IAAs) and AUXIN RESPONSE FACTORs (ARFs), was demonstrated to accompany SE induction. Thus, the extensive crosstalk between the hormones, in particular, auxin and the TFs, was revealed to play a central role in the SE-regulatory network. Accordingly, LEAFY COTYLEDON (LEC1 and LEC2), BABY BOOM (BBM), AGAMOUS-LIKE15 (AGL15) and WUSCHEL (WUS) were found to constitute the central part of the complex regulatory network that directs the somatic plant cell towards embryogenic development in response to auxin. The revealing picture shows a high degree of complexity of the regulatory relationships between the TFs of the SE-regulatory network, which involve direct and indirect interactions and regulatory feedback loops. This review examines the recent advances in studies on the auxin-controlled genetic network, which is involved in the mechanism of SE induction and focuses on the complex regulatory relationships between the down-and up-stream targets of the SE-regulatory TFs. In particular, the outcomes from investigations on Arabidopsis, which became a model plant in research on genetic control of SE, are presented. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.},

note = {52},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85054500845,

title = {Trichostatin a triggers an embryogenic transition in arabidopsis explants via an auxin-related pathway},

author = { B. Wójcikowska and M. Botor and J. Morończyk and A.M. Wójcik and T. Nodzyński and J. Karcz and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054500845&doi=10.3389%2ffpls.2018.01353&partnerID=40&md5=cbe7e1e0677493466506c918a06e7cf0},

doi = {10.3389/fpls.2018.01353},

issn = {1664462X},

year  = {2018},

date = {2018-01-01},

journal = {Frontiers in Plant Science},

volume = {9},

publisher = {Frontiers Media S.A.},

abstract = {Auxin is an important regulator of plant ontogenies including embryo development and the exogenous application of this phytohormone has been found to be necessary for the induction of the embryogenic response in plant explants that have been cultured in vitro. However, in the present study, we show that treatment of Arabidopsis explants with trichostatin A (TSA), which is a chemical inhibitor of histone deacetylases, induces somatic embryogenesis (SE) without the exogenous application of auxin. We found that the TSA-treated explants generated somatic embryos that developed efficiently on the adaxial side of the cotyledons, which are the parts of an explant that are involved in auxin-induced SE. A substantial reduction in the activity of histone deacetylase (HDAC) was observed in the TSA-treated explants, thus confirming a histone acetylation-related mechanism of the TSA-promoted embryogenic response. Unexpectedly, the embryogenic effect of TSA was lower on the auxin-supplemented media and this finding further suggests an auxin-related mechanism of TSA-induced SE. Congruently, we found a significantly increased content of indolic compounds, which is indicative of IAA and an enhanced DR5::GUS signal in the TSA-treated explants. In line with these results, two of the YUCCA genes (YUC1 and YUC10), which are involved in auxin biosynthesis, were found to be distinctly up-regulated during TSA-induced SE and their expression was colocalised with the explant sites that are involved in SE. Beside auxin, ROS were extensively accumulated in response to TSA, thereby indicating that a stress-response is involved in TSA-triggered SE. Relevantly, we showed that the genes encoding the transcription factors (TFs) that have a regulatory function in auxin biosynthesis including LEC1, LEC2, BBM, and stress responses (MYB118) were highly up-regulated in the TSA-treated explants. Collectively, the results provide several pieces of evidence about the similarities between the molecular pathways of SE induction that are triggered by TSA and 2,4-D that involve the activation of the auxin-responsive TF genes that have a regulatory function in auxin biosynthesis and stress responses. The study suggests the involvement of histone acetylation in the auxin-mediated release of the embryogenic program of development in the somatic cells of Arabidopsis. © 2018 Wójcikowska, Botor, Morończyk, Wójcik, Nodzyński, Karcz and Gaj.},

note = {36},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85049933562,

title = {Maternal auxin supply contributes to early embryo patterning in Arabidopsis},

author = { H.S. Robert and C. Park and C.L. Gutièrrez and B. Wójcikowska and A. Pěnčík and O. Novák and J. Chen and W. Grunewald and T. Dresselhaus and J. Friml and T. Laux},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049933562&doi=10.1038%2fs41477-018-0204-z&partnerID=40&md5=fa39bd5e8f38a4fcbc900f771ff22a6c},

doi = {10.1038/s41477-018-0204-z},

issn = {20550278},

year  = {2018},

date = {2018-01-01},

journal = {Nature Plants},

volume = {4},

number = {8},

pages = {548-553},

publisher = {Palgrave Macmillan Ltd.},

abstract = {The angiosperm seed is composed of three genetically distinct tissues: the diploid embryo that originates from the fertilized egg cell, the triploid endosperm that is produced from the fertilized central cell, and the maternal sporophytic integuments that develop into the seed coat1. At the onset of embryo development in Arabidopsis thaliana, the zygote divides asymmetrically, producing a small apical embryonic cell and a larger basal cell that connects the embryo to the maternal tissue2. The coordinated and synchronous development of the embryo and the surrounding integuments, and the alignment of their growth axes, suggest communication between maternal tissues and the embryo. In contrast to animals, however, where a network of maternal factors that direct embryo patterning have been identified3,4, only a few maternal mutations have been described to affect embryo development in plants5–7. Early embryo patterning in Arabidopsis requires accumulation of the phytohormone auxin in the apical cell by directed transport from the suspensor8–10. However, the origin of this auxin has remained obscure. Here we investigate the source of auxin for early embryogenesis and provide evidence that the mother plant coordinates seed development by supplying auxin to the early embryo from the integuments of the ovule. We show that auxin response increases in ovules after fertilization, due to upregulated auxin biosynthesis in the integuments, and this maternally produced auxin is required for correct embryo development. © 2018, The Author(s).},

note = {91},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85044541795,

title = {Azacitidine (5-AzaC)-treatment and mutations in DNA methylase genes affect embryogenic response and expression of the genes that are involved in somatic embryogenesis in Arabidopsis},

author = { D. Grzybkowska and J. Morończyk and B. Wójcikowska and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044541795&doi=10.1007%2fs10725-018-0389-1&partnerID=40&md5=1bb66f4e3178174a22c61d3a216b5eec},

doi = {10.1007/s10725-018-0389-1},

issn = {01676903},

year  = {2018},

date = {2018-01-01},

journal = {Plant Growth Regulation},

volume = {85},

number = {2},

pages = {243-256},

publisher = {Springer Netherlands},

abstract = {Epigenetic processes including DNA methylation play a pivotal role in regulating the genes that control plant development. In contrast to in planta development, the contribution of DNA methylation to the morphogenic processes that are induced in vitro are much less recognised. Hence, in the present study, we analysed the impact of DNA methylation on somatic embryogenesis (SE) that was induced in Arabidopsis. The results demonstrated a decrease in the global DNA methylation level during SE that contrasted with the up-regulation of MET1 and CMT3 DNA methylases and the down-regulation of DNA demethylases (ROS1; DME and DML2). Hence, the global DNA methylation level appears not to correlate with the transcriptional activity of the genes encoding DNA methylases/demethylases, thereby implying the complexity of the regulatory mechanism that controls the DNA methylation status of the SE-epigenome. Moreover, distinct changes in the expression level of the SE-regulatory genes were indicated in the 5-AzaC-treated and DNA methylase mutant cultures. Accordingly, a significant repression of the LEC2, LEC1 and BBM genes was found in the 5-AzaC-treated culture that was incapable of SE induction. In contrast, the distinct up-regulation of these genes was observed in the drm1drm2 and drm1drm2cmt3 mutant cultures with an improved embryogenic response. The modulated expression of DNA methylase genes and the significantly modified embryogenic response of the met1 and drm mutants imply that both the maintenance and the de novo pathway of DNA methylation are engaged in the regulation of SE in Arabidopsis. © 2018, The Author(s).},

note = {37},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85014060247,

title = {Expression profiling of AUXIN RESPONSE FACTOR genes during somatic embryogenesis induction in Arabidopsis},

author = { B. Wójcikowska and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85014060247&doi=10.1007%2fs00299-017-2114-3&partnerID=40&md5=964d2525fd57bcaaf03c35f7ce9b8080},

doi = {10.1007/s00299-017-2114-3},

issn = {07217714},

year  = {2017},

date = {2017-01-01},

journal = {Plant Cell Reports},

volume = {36},

number = {6},

pages = {843-858},

publisher = {Springer Verlag},

abstract = {Key message: Extensive modulation of numerous ARF transcripts in the embryogenic culture of Arabidopsis indicates a substantial role of auxin signaling in the mechanism of somatic embryogenesis induction. Abstract: Somatic embryogenesis (SE) is induced by auxin in plants and auxin signaling is considered to play a key role in the molecular mechanism that controls the embryogenic transition of plant somatic cells. Accordingly, the expression of AUXIN RESPONSE FACTOR (ARF) genes in embryogenic culture of Arabidopsis was analyzed. The study revealed that 14 of the 22 ARFs were transcribed during SE in Arabidopsis. RT-qPCR analysis indicated that the expression of six ARFs (ARF5; ARF6; ARF8; ARF10; ARF16; and ARF17) was significantly up-regulated, whereas five other genes (ARF1; ARF2; ARF3; ARF11; and ARF18) were substantially down-regulated in the SE-induced explants. The activity of ARFs during SE was also monitored with GFP reporter lines and the ARFs that were expressed in areas of the explants engaged in SE induction were detected. A functional test of ARFs transcribed during SE was performed and the embryogenic potential of the arf mutants and overexpressor lines was evaluated. ARFs with a significantly modulated expression during SE coupled with an impaired embryogenic response of the relevant mutant and/or overexpressor line, including ARF1, ARF2, ARF3, ARF5, ARF6, ARF8, and ARF11 were indicated as possibly being involved in SE induction. The study provides evidence that embryogenic induction strongly depends on ARFs, which are key regulators of the auxin signaling. Some clues on the possible functions of the candidate ARFs, especially ARF5, in the mechanism of embryogenic transition are discussed. The results provide guidelines for further research on the auxin-related functional genomics of SE and the developmental plasticity of somatic cells. © 2017, The Author(s).},

note = {73},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84925493018,

title = {ERF022 impacts the induction of somatic embryogenesis in Arabidopsis through the ethylene-related pathway},

author = { K. Nowak and B. Wójcikowska and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84925493018&doi=10.1007%2fs00425-014-2225-9&partnerID=40&md5=484ed96fbd6cd5bdc8273abcabee016a},

doi = {10.1007/s00425-014-2225-9},

issn = {00320935},

year  = {2015},

date = {2015-01-01},

journal = {Planta},

volume = {241},

number = {4},

pages = {967-985},

publisher = {Springer Verlag},

abstract = {Main conclusion: TheERF022gene was found to affect embryogenic transition in somatic cells in Arabidopsis via the ethylene-related pathway. The study provides evidence thatERF022-LEC2interaction is involved in the auxin–ethylene crosstalk that operates in somatic embryogenesis induction.The ERF022 gene of the ERF family was previously identified among the transcription factor genes that were differentially expressed in an embryogenic culture of Arabidopsis. A strong inhibition of the gene was found to be associated with the induction of somatic embryogenesis (SE) and an erf022 mutant was indicated to display a substantially impaired capacity for SE. Therefore, the molecular function of ERF022 in the induction of SE was studied in the present work. A phenotype of an erf022 mutant was indicated as being related to an increased content of ethylene. The results further suggest that the ERF022 controls the genes that are involved in both the biosynthesis (ACS7) and signalling (ERF1; ETR1) of ethylene and indicate that the ERF022 is a new regulatory element in ethylene-related responses that negatively control the ethylene content and perception. It is proposed that the negative impact of ethylene on the induction of SE may result from a modulation of the auxin-related genes that control the embryogenic transition in somatic cells. Among them, the LEC2, which is a key regulator of the induction of SE through the stimulation of auxin synthesis, was possibly related to ERF022. The results of the study provide new hormone-related clues to define the genetic network that governs SE. A putative model of the regulatory pathway is proposed that is involved in the induction of SE in which the auxin–ethylene interactions are controlled by ERF022 and LEC2 and their targets. © 2014, The Author(s).},

note = {43},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84925341356,

title = {LEAFY COTYLEDON2-mediated control of the endogenous hormone content: implications for the induction of somatic embryogenesis in Arabidopsis},

author = { B. Wójcikowska and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84925341356&doi=10.1007%2fs11240-014-0689-8&partnerID=40&md5=80f9d7825c98b430bac8911bfabe70fb},

doi = {10.1007/s11240-014-0689-8},

issn = {01676857},

year  = {2015},

date = {2015-01-01},

journal = {Plant Cell, Tissue and Organ Culture},

volume = {121},

number = {1},

pages = {255-258},

publisher = {Kluwer Academic Publishers},

abstract = {The overexpression of LEAFY COTYLEDON2 (LEC2) in Arabidopsis, results in the induction of somatic embryogenesis (SE) in an auxin-free environment and the stimulation of auxin biosynthesis was postulated as being involved in this response. To gain further insight into the hormone-related functions of LEC2 in SE, the effect of LEC2 overexpression on the hormone content in Arabidopsis plants and in vitro cultured explants was analysed. In addition to indole-3-acetic acid (IAA) and cytokinins (CKs), which are hormones that play a key role in plant development, the stress-related hormones, abscisic acid (ABA) and salicylic acid (SA), which are involved in the stress response that is related to SE-induction, were analysed. Together with the observations that LEC2 activity can compensate for the auxin treatment required for SE induction (Ledwoń and Gaj in Plant Tissue Cell Org Cult 28:1677–1688; 2009) and LEC2 may control auxin biosynthesis pathway during SE induction (Wójcikowska et al. in Planta 238:425–440; 2013), a significant increase in the IAA content in response to LEC2 overexpression found in the present study supply further evidence that LEC2-controlled auxin biosynthesis may be involved in the mechanism that triggers embryogenic development in somatic cells. Moreover, LEC2-controlled SE induction was shown to be associated with a decrease in the total content of CKs and an accumulation of some specific CK types, including isopentenyl-adenin and cis-zeatin. Additionally, an increase in SA and a decrease in ABA content were also found to be related to LEC2 activity in embryogenically induced tissue. The obtained results provide further proof of the close link between LEC2 and the establishment of the hormonal environment that is required for the promotion of SE. © 2014, The Author(s).},

note = {15},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84882990244,

title = {LEAFY COTYLEDON2 (LEC2) promotes embryogenic induction in somatic tissues of Arabidopsis, via YUCCA-mediated auxin biosynthesis},

author = { B. Wójcikowska and K. Jaskóła and P. Gąsiorek and M. Meus and K. Nowak and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84882990244&doi=10.1007%2fs00425-013-1892-2&partnerID=40&md5=b86ad3f6b078c67f6368504f82397b4b},

doi = {10.1007/s00425-013-1892-2},

issn = {00320935},

year  = {2013},

date = {2013-01-01},

journal = {Planta},

volume = {238},

number = {3},

pages = {425-440},

publisher = {Springer Verlag},

abstract = {The LEAFY COTYLEDON2 (LEC2) transcription factor with a plant-specific B3 domain plays a central role in zygotic and somatic embryogenesis (SE). LEC2 overexpression induced in planta leads to spontaneous somatic embryo formation, but impairs the embryogenic response of explants cultured in vitro under auxin treatment. The auxin-related functions of LEC2 appear during SE induction, and the aim of the present study was to gain further insights into this phenomenon. To this end, the effect of LEC2 overexpression on the morphogenic responses of Arabidopsis explants cultured in vitro under different auxin treatments was evaluated. The expression profiles of the auxin biosynthesis genes were analysed in embryogenic cultures with respect to LEC2 activity. The results showed that LEC2 overexpression severely modifies the requirement of cultured explants for an exogenous auxin concentration at a level that is effective in SE induction and suggested an increase in the auxin content in 35S::LEC2-GR transgenic explants. The assumption of an LEC2 promoted increase in endogenous auxin in cultured explants was further supported by the expression profiling of the genes involved in auxin biosynthesis. The analysis indicated that YUCCAs and TAA1, working in the IPA-YUC auxin biosynthesis pathway, are associated with SE induction, and that the expression of three YUCCA genes (YUC1; YUC4 and YUC10) is associated with LEC2 activity. The results also suggest that the IAOx-mediated auxin biosynthesis pathway involving ATR1/MYB34 and CYP79B2 does not seem to be involved in SE induction. We conclude that de novo auxin production via the tryptophan-dependent IPA-YUC auxin biosynthesis pathway is implicated in SE induction, and that LEC2 plays a key role in this mechanism. © 2013 The Author(s).},

note = {97},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84859873413,

title = {Evaluation of different embryogenic systems for production of true somatic embryos in Arabidopsis},

author = { K. Nowak and B. Wójcikowska and K.P. Szyrajew and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84859873413&doi=10.1007%2fs10535-012-0063-9&partnerID=40&md5=5a3da4545127c05ea9df9d0597eb6ad3},

doi = {10.1007/s10535-012-0063-9},

issn = {00063134},

year  = {2012},

date = {2012-01-01},

journal = {Biologia Plantarum},

volume = {56},

number = {3},

pages = {401-408},

abstract = {Somatic embryogenesis (SE) in Arabidopsis was induced using various systems, including auxin treatment of in vitro cultured explants (immature zygotic embryos; IZEs) and transgenic plants overexpressing embryogenesis-related transcription factors, e. g. LEC2 together with the GUS reporter gene under control of the auxin-induced DR5 promoter. The study indicated that the SE-systems used gave different embryogenic capacities for the production of true embryos. The highest ratio of true embryos (75 %) was found among embryo-like structures in transgenic seedlings overexpressing LEC2. Analysis of in vitro induced SE systems indicated that in somatic embryos produced in response to exogenous auxin treatment the formation of root poles is frequently disturbed. A lack of a properly formed root meristem was observed in 35-80 % of in vitro induced somatic embryos, in dependence on auxin concentration and duration of treatment. © 2012 Springer Science+Business Media B.V.},

note = {8},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84856920216,

title = {Immature zygotic embryo cultures of Arabidopsis. Amodel system for molecular studies on morphogenic pathways induced in vitro},

author = { M. Kraut and B. Wójcikowska and A. Ledwoń and M.D. Gaj},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84856920216&doi=10.2478%2fv10182-011-0028-x&partnerID=40&md5=c1b1164c7aa0b0ac58fd4ed7cbf5b22b},

doi = {10.2478/v10182-011-0028-x},

issn = {00015296},

year  = {2011},

date = {2011-01-01},

journal = {Acta Biologica Cracoviensia Series Botanica},

volume = {53},

number = {2},

pages = {59-67},

abstract = {To understand the molecular mechanism controlling in vitro plant morphogenesis, a culture system enabling induction of alternative morphogenic pathways (somatic embryogenesis; SE; shoot organogenesis; ORG) in a well defined population of somatic cells is needed. Arabidopsis is the most useful model plant for genomic studies, but a system in which SE or ORG can be induced alternatively in the same type of explant has not been proposed. Immature zygotic embryos (IZEs) of Arabidopsis provide the only explants with embryogenic potential, and have been recommended for studying mechanisms of SE induced in vitro. This study was aimed at defining culture conditions promoting induction of alternative morphogenic pathways: shoot ORG in IZE explants. The established protocol involves pretreatment of IZE explants with liquid auxin-rich callus induction (CIM) medium, followed by subculture on solid cytokinin-rich shoot induction medium (SIM). The method enables efficient shoot induction in Columbia (Col-0) and Wassilewskija (Ws), genotypes commonly used in molecular studies. During 3 weeks of culture up to 90% of Col-0 and 70% of Ws explants regenerated shoots via an indirect morphogenic pathway. We analyzed the qRT-PCR expression patterns of the LEC (LEC1; LEC2 and FUS3) genes, the key regulators of Arabidopsis embryogenesis, in the IZE explants induced to promote shoot ORG. The sharp decline of LEC expression on SIM medium confirmed that culture of Arabidopsis IZE explants enables experimental manipulation of the morphogenic response of somatic cells. A scheme illustrating various in vitro morphogenic responses of IZEs in relation to hormonal treatment is presented. © Polish Academy of Sciences and Jagiellonian University, Cracow 2011.},

note = {11},

keywords = {},

pubstate = {published},

tppubtype = {article}

}