Petko Mladenov

Dr. Petko Mladenov


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 March 2023 in Agronomy
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PMPetko Mladenov
Petko Mladenov
Sibel Dzhevdet AzizSibel Dzhevdet Aziz
Sibel Dzhevdet Aziz
ETElena TOPALOVA
Elena TOPALOVA
Jenny RenautJenny Renaut
Jenny Renaut
SPSébastien Planchon
Sébastien Planchon
NTNasya TOMLEKOVA
Nasya TOMLEKOVA
Drought compromises edible vegetable production worldwide, including common bean (Phaseolus vulgaris L.) an economically important crop that is highly dependent on optimum rainfall or abundant irrigation. In the present study, phenotypic data of 26 Bulgarian common bean mutant lines and cultivars subjected to drought stress has been summarized, and drought stress reaction was evaluated by chlorophyll fluorescence and proteomics approaches. Several basic photosynthetic parameters were examined during treatment to evaluate the drought stress response, and the mutant lines showed different responses. Subsequently, a relationship was found between productivity and photosynthetic performance with the expression of ribulose-1,5-bisphosphate carboxylase through comparative 2D-gel based electrophoresis; accumulation of the well-known stress-related proteins markers dehydrins and small heat shock proteins was established as well. These findings support the further selection of drought tolerant common bean lines for a sustainable agriculture.

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Journal Article
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PMPetko Mladenov
Petko Mladenov
DZDiana Zasheva
Diana Zasheva
SPSébastien Planchon
Sébastien Planchon
CLCéline C. Leclercq
Céline C. Leclercq
DFDenis Falconet
Denis Falconet
XDXin Deng
Xin Deng
Global warming and drought stress are expected to have a negative impact on agricultural productivity. Desiccation-tolerant species, which are able to tolerate the almost complete desiccation of their vegetative tissues, are appropriate models to study extreme drought tolerance and identify novel approaches to improve the resistance of crops to drought stress. In the present study, to better understand what makes resurrection plants extremely tolerant to drought, we performed transmission electron microscopy and integrative large-scale proteomics, including organellar and phosphorylation proteomics, and combined these investigations with previously published transcriptomic and metabolomics data from the resurrection plant Haberlea rhodopensis. The results revealed new evidence about organelle and cell preservation, posttranscriptional and posttranslational regulation, photosynthesis, primary metabolism, autophagy, and cell death in response to desiccation in H. rhodopensis. Different protective intrinsically disordered proteins, such as late embryogenesis abundant (LEA) proteins, thaumatin-like proteins (TLPs), and heat shock proteins (HSPs), were detected. We also found a constitutively abundant dehydrin in H. rhodopensis whose phosphorylation levels increased under stress in the chloroplast fraction. This integrative multi-omics analysis revealed a systemic response to desiccation in H. rhodopensis and certain targets for further genomic and evolutionary studies on DT mechanisms and genetic engineering towards the improvement of drought tolerance in crops.

7 November 2024 in Molecules
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DZDiana Zasheva
Diana Zasheva
PMPetko Mladenov
Petko Mladenov
SZSilvina Zapryanova
Silvina Zapryanova
ZGZlatina Gospodinova
Zlatina Gospodinova
Mariyana Georgieva-TsenovaMariyana Georgieva-Tsenova
Mariyana Georgieva-Tsenova
LSLyudmila Simova
Lyudmila Simova
Breast cancer is the second leading cause of death among women, and the number of mortal cases in diagnosed patients is constantly increasing. The search for new plant compounds with antitumor effects is very important because of the side effects of conventional therapy and the development of drug resistance in cancer cells. The use of plant substances in medicine has been well known for centuries, but the exact mechanism of their action is far from being elucidated. The molecular mechanisms of cytotoxicity exerted by secondary metabolites and bioactive peptides of plant origin on breast cancer cell lines are the subject of this review.

1 July 2023 in Separations
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DZDiana Zasheva
Diana Zasheva
PMPetko Mladenov
Petko Mladenov
KRKrasimir Rusanov
Krasimir Rusanov
SSSvetlana Simova
Svetlana Simova
SZSilvina Zapryanova
Silvina Zapryanova
DDDimitar Djilianov
Dimitar Djilianov
Breast cancer is among the most problematic diseases and a leading cause of death in women. The methods of therapy widely used, so far, are often with many side effects, seriously hampering patients’ quality of life. To overcome these constraints, new cancer treatment alternatives are constantly tested, including bioactive compounds of plant origin. Our aim was to study the effects of Haberlea rhodopensis methanol extract fractions on cell viability and proliferation of two model breast cancer cell lines with different characteristics. In addition to the strong reduction in cell viability, two of the fractions showed significant influence on the proliferation rate of the hormone receptor expressing MCF7 and the triple negative MDA-MB231 breast cancer cell lines. No significant effects on the benign MCF10A cell line were observed. We applied a large scale non-targeted approach to purify and identify highly abundant compounds from the active fractions of H. rhodopensis extracts. By the combined NMR/MS approach, myconoside was identified in the fractions and hispidulin 8-C-(6-O-acetyl-2″-O-syringoyl-β-glucopyranoside) was found in one of them. We further performed molecular docking analysis of possible myconoside interactions with several proteins, important for breast cancer proliferation. High probability of binding was established for GLUT1 transporter, estrogen receptor and MYST acetyltransferase. Our results are a good background for future studies on the use of myconoside for targeted breast cancer therapy.

7 February 2024 in Metabolites
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DDDimitar Djilianov
Dimitar Djilianov
DMDaniela Moyankova
Daniela Moyankova
PMPetko Mladenov
Petko Mladenov
TTTanya Ivanova Topouzova-Hristova
Tanya Ivanova Topouzova-Hristova
AKAneliya Kostadinova
Aneliya Kostadinova
LSLyudmila Simova
Lyudmila Simova
Resurrection plant species are a group of higher plants whose vegetative tissues are able to withstand long periods of almost full desiccation and recover quickly upon rewatering. Apart from being a model system for studying desiccation tolerance, resurrection plant species appear to be a valuable source of metabolites, with various areas of application. A significant number of papers have been published in recent years with respect to the extraction and application of bioactive compounds from higher resurrection plant species in various test systems. Promising results have been obtained with respect to antioxidative and antiaging effects in various test systems, particularly regarding valuable anticancer effects in human cell lines. Here, we review the latest advances in the field and propose potential mechanisms of action of myconoside—a predominant secondary compound in the European members of the Gesneriaceae family. In addition, we shed light on the possibilities for the sustainable use of natural products derived from resurrection plants.

19 December 2023 in BMC Plant Biology
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PMPetko Mladenov
Petko Mladenov
XWXiaohua Wang
Xiaohua Wang
ZYZhaolin Yang
Zhaolin Yang
DDDimitar Djilianov
Dimitar Djilianov
XDXin Deng
Xin Deng
Background: Drought is one of the main consequences of global climate change and this problem is expected to intensify in the future. Resurrection plants evolved the ability to withstand the negative impact of long periods of almost complete desiccation and to recover at rewatering. In this respect, many physiological, transcriptomic, proteomic and genomic investigations have been performed in recent years, however, few epigenetic control studies have been performed on these valuable desiccation-tolerant plants so far. Results: In the present study, for the first time for resurrection plants we provide evidences about the differential chromatin accessibility of Haberlea rhodopensis during desiccation stress by ATAC-seq (Assay for Transposase Accessible Chromatin with high-throughput sequencing). Based on gene similarity between species, we used the available genome of the closely related resurrection plant Dorcoceras hygrometricum to identify approximately nine hundred transposase hypersensitive sites (THSs) in H. rhodopensis. The majority of them corresponds to proximal and distal regulatory elements of different genes involved in photosynthesis, carbon metabolism, synthesis of secondary metabolites, cell signalling and transcriptional regulation, cell growth, cell wall, stomata conditioning, chaperons, oxidative stress, autophagy and others. Various types of binding motifs recognized by several families of transcription factors have been enriched from the THSs found in different stages of drought. Further, we used the previously published RNA-seq data from H. rhodopensis to evaluate the expression of transcription factors putatively interacting with the enriched motifs, and the potential correlation between the identified THS and the expression of their corresponding genes. Conclusions: These results provide a blueprint for investigating the epigenetic regulation of desiccation tolerance in resurrection plant H. rhodopensis and comparative genomics between resurrection and non-resurrection species with available genome information.