Searching for the mechanism that mediates mefenoxam-acquired resistance in Phytophthora infestans and how it is regulated

2021 ◽  
Author(s):  
Juliana González-Tobón ◽  
Richard Childers ◽  
Alejandra Rodríguez ◽  
William Fry ◽  
Kevin L. Myers ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Molecular Mechanisms ◽  
Acquired Resistance ◽  
Phytophthora Species ◽  
Regulatory Process ◽  
Differentially Expressed ◽  
Potential Association ◽  
Other Substances ◽  
Blight Disease ◽  
Computational Analyses

Phytophthora infestans, the causal agent of late blight disease of potatoes, is mainly controlled by the use of fungicides. Isolates that are resistant to commonly used fungicides have been reported. Also, several studies show that originally mefenoxam-sensitive isolates acquire resistance to this fungicide when exposed to sub-lethal concentrations. This phenomenon, termed ‘mefenoxam-acquired resistance’, has been observed in different Phytophthora species and seems to be unique to mefenoxam. In this study, we aimed to elucidate the molecular mechanism mediating this type of resistance as well as a possible regulatory process behind it. A combination of computational analyses and experimental approaches was used to identify differentially expressed genes with a potential association to the phenomenon. These genes were classified into seven functional groups. Most of them seem to be associated with a pleiotropic drug resistance (PDR) phenotype, typically involved in the expulsion of diverse metabolites, drugs, or other substances out of the cell. Despite the importance of RNApolI for the constitutive resistance of P. infestans to mefenoxam, our results indicate no clear interaction between this protein and the acquisition of mefenoxam resistance. Several small non-coding RNAs (ncRNAs) were found to be differentially expressed and specifically related to genes mediating the PDR phenotype, thus suggesting a possible regulatory process. We propose a model of the molecular mechanisms acting within the cell when P. infestans acquires resistance to mefenoxam after exposed to sub-lethal concentrations of the fungicide. This study provides important insights into P. infestans’ cellular and regulatory functionalities.

scholarly journals Acquired Resistance to Mefenoxam in Sensitive Isolates of Phytophthora infestans

2015 ◽  
Vol 105 (3) ◽  
pp. 342-349 ◽  
Author(s):  
Richard Childers ◽  
Giovanna Danies ◽  
Kevin Myers ◽  
Zhangjun Fei ◽  
Ian M. Small ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Acquired Resistance ◽  
Field Resistance ◽  
Differentially Expressed ◽  
Initial Assessment ◽  
Systemic Fungicide ◽  
Mannitol Dehydrogenase ◽  
Negative Effect ◽  
Sensitive Isolate ◽  
Blight Disease

The systemic fungicide mefenoxam has been important in the control of late blight disease caused by Phytophthora infestans. This phenylamide fungicide has a negative effect on the synthesis of ribosomal RNA; however, the genetic basis for inherited field resistance is still not completely clear. We recently observed that a sensitive isolate became tolerant after a single passage on mefenoxam-containing medium. Further analyses revealed that all sensitive isolates tested (in three diverse genotypes) acquired this resistance equally quickly. In contrast, isolates that were “resistant” to mefenoxam in the initial assessment (stably resistant) did not increase in resistance upon further exposure. However, there appeared to be a cost associated with acquired resistance in the initially sensitive isolates, in that isolates with acquired resistance grew more slowly on mefenoxam-free medium than did the same isolates that had never been exposed to mefenoxam. The acquired resistance of the sensitive isolates declined slightly with subsequent culturing on medium free of mefenoxam. To investigate the mechanism of acquired resistance, we employed strand-specific RNA sequencing. Many differentially expressed genes were genotype specific, but one set of genes was differentially expressed in all genotypes. Among these were several genes (a phospholipase “Pi-PLD-like-3,” two ATP-binding cassette superfamily [ABC] transporters, and a mannitol dehydrogenase) that were up-regulated and whose function might contribute to a resistance phenotype.

scholarly journals Is the Phenomenon of Mefenoxam-Acquired Resistance in Phytophthora infestans Universal?

Plant Disease ◽  
2020 ◽  
Vol 104 (1) ◽  
pp. 211-221
Author(s):  
Juliana González-Tobón ◽  
Richard Childers ◽  
Carolina Olave ◽  
Melissa Regnier ◽  
Alejandra Rodríguez-Jaramillo ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Acquired Resistance ◽  
Phytophthora Species ◽  
Economic Losses ◽  
Phytophthora Spp ◽  
Late Blight Disease ◽  
Blight Disease ◽  
And Control ◽  
Sublethal Concentrations

Phytophthora infestans is the causal agent of late blight disease of potatoes and tomatoes. This disease causes devastating economic losses each year, and control is mainly achieved by the use of fungicides. Unfortunately, populations of P. infestans resistant to fungicides have been documented. Furthermore, studies have reported that sensitive isolates to the phenylamide fungicide, mefenoxam, become less sensitive in vitro after a single passage through sublethal concentrations of fungicide-amended medium. The first objective of this study was to investigate if isolates of P. infestans are capable of acquiring resistance to two additional systemic fungicides, fluopicolide (benzamide) and cymoxanil (cyanoacetamide-oxime). In contrast to the situation with mefenoxam, exposure of isolates to sublethal concentrations of fluopicolide and cymoxanil did not induce reduced sensitivity to these two fungicides. The second objective was to assess if reduced sensitivity to mefenoxam could occur in naturally sensitive isolates of other Phytophthora species and of Phytopythium sp., another oomycete plant pathogen. All Phytophthora spp. assessed (P. infestans, P. betacei, and P. pseudocryptogea) as well as Phytopythium sp. acquired resistance to mefenoxam after previous exposure through medium containing 1 µg ml−1 of mefenoxam. Interestingly, isolate 66 of Phytopythium sp. and the isolate of P. pseudocryptogea tested do not seem to be acquiring resistance to mefenoxam after exposure to medium containing 5 µg ml−1 of this fungicide. The tested isolates of P. palmivora and P. cinnamomi were extremely sensitive to mefenoxam, and thus it was not possible to perform a second transfer to access acquisition of resistance to this fungicide.

scholarly journals Improved Genome Sequence and Gene Annotation Resource for the Potato Late Blight Pathogen Phytophthora infestans

2020 ◽  
Vol 33 (8) ◽  
pp. 1025-1028
Author(s):  
Yoonyoung Lee ◽  
Kwang-Soo Cho ◽  
Jin-Hee Seo ◽  
Kee Hoon Sohn ◽  
Maxim Prokchorchik
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Molecular Mechanisms ◽  
Gene Annotation ◽  
Potato Late Blight ◽  
Sequencing Technologies ◽  
Oxford Nanopore ◽  
Long Read ◽  
Blight Disease ◽  
Late Blight Pathogen

Phytophthora infestans is a devastating pathogen causing potato late blight (Solanum tuberosum). Here we report the sequencing, assembly and genome annotation for two Phytophthora infestans isolates sampled in Republic of Korea. Genome sequencing was carried out using long read (Oxford Nanopore) and short read (Illumina Nextseq) sequencing technologies that significantly improved the contiguity and quality of P. infestans genome assembly. Our resources would help researchers better understand the molecular mechanisms by which P. infestans causes late blight disease in the future.

scholarly journals The Omics Hunt for Novel Molecular Markers of Resistance to Phytophthora infestans

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 61
Author(s):  
Hana Dufková ◽  
Miroslav Berka ◽  
Marie Greplová ◽  
Šarlota Shejbalová ◽  
Romana Hampejsová ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Molecular Mechanisms ◽  
Protein Markers ◽  
Resistance Markers ◽  
Late Blight Disease ◽  
Total Pool ◽  
Resistance Protein ◽  
Blight Disease ◽  
Moderately Resistant ◽  
Resistant Genotypes

Wild Solanum accessions are a treasured source of resistance against pathogens, including oomycete Phytophthora infestans, causing late blight disease. Here, Solanum pinnatisectum, Solanum tuberosum, and the somatic hybrid between these two lines were analyzed, representing resistant, susceptible, and moderately resistant genotypes, respectively. Proteome and metabolome analyses showed that the infection had the highest impact on leaves of the resistant plant and indicated, among others, an extensive remodeling of the leaf lipidome. The lipidome profiling confirmed an accumulation of glycerolipids, a depletion in the total pool of glycerophospholipids, and showed considerable differences between the lipidome composition of resistant and susceptible genotypes. The analysis of putative resistance markers pinpointed more than 100 molecules that positively correlated with resistance including phenolics and cysteamine, a compound with known antimicrobial activity. Putative resistance protein markers were targeted in an additional 12 genotypes with contrasting resistance to P. infestans. At least 27 proteins showed a negative correlation with the susceptibility including HSP70-2, endochitinase B, WPP domain-containing protein, and cyclase 3. In summary, these findings provide insights into molecular mechanisms of resistance against P. infestans and present novel targets for selective breeding.

Identification of Differentially Expressed Genes Associated with Papillary Thyroid Carcinoma

2020 ◽  
Vol 23 (6) ◽  
pp. 546-553
Author(s):  
Hongyuan Cui ◽  
Mingwei Zhu ◽  
Junhua Zhang ◽  
Wenqin Li ◽  
Lihui Zou ◽  
...  
Keyword(s):  
Papillary Thyroid Carcinoma ◽  
Thyroid Carcinoma ◽  
Differentially Expressed Genes ◽  
Molecular Mechanisms ◽  
Cellular Proliferation ◽  
Mrna Level ◽  
Thyroid Tissue ◽  
Differentially Expressed ◽  
Thyroid Tumors ◽  
Papillary Thyroid

Objective: Next-generation sequencing (NGS) was performed to identify genes that were differentially expressed between normal thyroid tissue and papillary thyroid carcinoma (PTC). Materials & Methods: Six candidate genes were selected and further confirmed with quantitative real-time polymerase chain reaction (qRT-PCR), and immunohistochemistry in samples from 24 fresh thyroid tumors and adjacent normal tissues. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was used to investigate signal transduction pathways of the differentially expressed genes. Results: In total, 1690 genes were differentially expressed between samples from patients with PTC and the adjacent normal tissue. Among these, SFRP4, ZNF90, and DCN were the top three upregulated genes, whereas KIRREL3, TRIM36, and GABBR2 were downregulated with the smallest p values. Several pathways were associated with the differentially expressed genes and involved in cellular proliferation, cell migration, and endocrine system tumor progression, which may contribute to the pathogenesis of PTC. Upregulation of SFRP4, ZNF90, and DCN at the mRNA level was further validated with RT-PCR, and DCN expression was further confirmed with immunostaining of PTC samples. Conclusion: These results provide new insights into the molecular mechanisms of PTC. Identification of differentially expressed genes should not only improve the tumor signature for thyroid tumors as a diagnostic biomarker but also reveal potential targets for thyroid tumor treatment.

Systems Biology Approaches Reveal a Multi-stress Responsive WRKY Transcription Factor and Stress Associated Gene Co-expression Networks in Chickpea

2019 ◽  
Vol 14 (7) ◽  
pp. 591-601 ◽  
Author(s):  
Aravind K. Konda ◽  
Parasappa R. Sabale ◽  
Khela R. Soren ◽  
Shanmugavadivel P. Subramaniam ◽  
Pallavi Singh ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Gene Networks ◽  
Molecular Mechanisms ◽  
Enrichment Analysis ◽  
Functional Enrichment Analysis ◽  
Wrky Transcription Factor ◽  
Functional Enrichment ◽  
Differentially Expressed ◽  
Callose Deposition ◽  
Significant Probability

Background: Chickpea is a nutritional rich premier pulse crop but its production encounters setbacks due to various stresses and understanding of molecular mechanisms can be ascribed foremost importance. Objective: The investigation was carried out to identify the differentially expressed WRKY TFs in chickpea in response to herbicide stress and decipher their interacting partners. Methods: For this purpose, transcriptome wide identification of WRKY TFs in chickpea was done. Behavior of the differentially expressed TFs was compared between other stress conditions. Orthology based cofunctional gene networks were derived from Arabidopsis. Gene ontology and functional enrichment analysis was performed using Blast2GO and STRING software. Gene Coexpression Network (GCN) was constructed in chickpea using publicly available transcriptome data. Expression pattern of the identified gene network was studied in chickpea-Fusarium interactions. Results: A unique WRKY TF (Ca_08086) was found to be significantly (q value = 0.02) upregulated not only under herbicide stress but also in other stresses. Co-functional network of 14 genes, namely Ca_08086, Ca_19657, Ca_01317, Ca_20172, Ca_12226, Ca_15326, Ca_04218, Ca_07256, Ca_14620, Ca_12474, Ca_11595, Ca_15291, Ca_11762 and Ca_03543 were identified. GCN revealed 95 hub genes based on the significant probability scores. Functional annotation indicated role in callose deposition and response to chitin. Interestingly, contrasting expression pattern of the 14 network genes was observed in wilt resistant and susceptible chickpea genotypes, infected with Fusarium. Conclusion: This is the first report of identification of a multi-stress responsive WRKY TF and its associated GCN in chickpea.

Radio-Susceptibility of Nasopharyngeal Carcinoma: Focus on Epstein- Barr Virus, MicroRNAs, Long Non-Coding RNAs and Circular RNAs

2020 ◽  
Vol 13 (3) ◽  
pp. 192-205 ◽  
Author(s):  
Fanghong Lei ◽  
Tongda Lei ◽  
Yun Huang ◽  
Mingxiu Yang ◽  
Mingchu Liao ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Regulatory Networks ◽  
Epstein Barr Virus ◽  
Molecular Mechanisms ◽  
Acquired Resistance ◽  
Treatment Strategies ◽  
Circular Rnas ◽  
Barr Virus ◽  
Non Coding Rnas ◽  
Epstein Barr

Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer. As a neoplastic disorder, NPC is a highly malignant squamous cell carcinoma that is derived from the nasopharyngeal epithelium. NPC is radiosensitive; radiotherapy or radiotherapy combining with chemotherapy are the main treatment strategies. However, both modalities are usually accompanied by complications and acquired resistance to radiotherapy is a significant impediment to effective NPC therapy. Therefore, there is an urgent need to discover effective radio-sensitization and radio-resistance biomarkers for NPC. Recent studies have shown that Epstein-Barr virus (EBV)-encoded products, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), which share several common signaling pathways, can function in radio-related NPC cells or tissues. Understanding these interconnected regulatory networks will reveal the details of NPC radiation sensitivity and resistance. In this review, we discuss and summarize the specific molecular mechanisms of NPC radio-sensitization and radio-resistance, focusing on EBV-encoded products, miRNAs, lncRNAs and circRNAs. This will provide a foundation for the discovery of more accurate, effective and specific markers related to NPC radiotherapy. EBVencoded products, miRNAs, lncRNAs and circRNAs have emerged as crucial molecules mediating the radio-susceptibility of NPC. This understanding will improve the clinical application of markers and inform the development of novel therapeutics for NPC.

scholarly journals Comparative transcriptomic and metabolomic analyses of carotenoid biosynthesis reveal the basis of white petal color in Brassica napus

Planta ◽  
2021 ◽  
Vol 253 (1) ◽  
Author(s):  
Ledong Jia ◽  
Junsheng Wang ◽  
Rui Wang ◽  
Mouzheng Duan ◽  
Cailin Qiao ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Molecular Mechanisms ◽  
Flower Color ◽  
Carotenoid Biosynthesis ◽  
Differentially Expressed ◽  
Transcriptome Data ◽  
Oilseed Crops ◽  
Qrt Pcr ◽  
Carotenoid Metabolism ◽  
Rapeseed Cultivar

Abstract Main conclusion The molecular mechanism underlying white petal color in Brassica napus was revealed by transcriptomic and metabolomic analyses. Abstract Rapeseed (Brassica napus L.) is one of the most important oilseed crops worldwide, but the mechanisms underlying flower color in this crop are known less. Here, we performed metabolomic and transcriptomic analyses of the yellow-flowered rapeseed cultivar ‘Zhongshuang 11’ (ZS11) and the white-flowered inbred line ‘White Petal’ (WP). The total carotenoid contents were 1.778-fold and 1.969-fold higher in ZS11 vs. WP petals at stages S2 and S4, respectively. Our findings suggest that white petal color in WP flowers is primarily due to decreased lutein and zeaxanthin contents. Transcriptome analysis revealed 10,116 differentially expressed genes with a fourfold or greater change in expression (P-value less than 0.001) in WP vs. ZS11 petals, including 1,209 genes that were differentially expressed at four different stages and 20 genes in the carotenoid metabolism pathway. BnNCED4b, encoding a protein involved in carotenoid degradation, was expressed at abnormally high levels in WP petals, suggesting it might play a key role in white petal formation. The results of qRT-PCR were consistent with the transcriptome data. The results of this study provide important insights into the molecular mechanisms of the carotenoid metabolic pathway in rapeseed petals, and the candidate genes identified in this study provide a resource for the creation of new B. napus germplasms with different petal colors.

scholarly journals Differential Morpho-Physiological and Transcriptomic Responses to Heat Stress in Two Blueberry Species

2021 ◽  
Vol 22 (5) ◽  
pp. 2481
Author(s):  
Jodi Callwood ◽  
Kalpalatha Melmaiee ◽  
Krishnanand P. Kulkarni ◽  
Amaranatha R. Vennapusa ◽  
Diarra Aicha ◽  
...  
Keyword(s):  
Heat Stress ◽  
Molecular Mechanisms ◽  
Stomatal Closure ◽  
Enrichment Analysis ◽  
Leaf Size ◽  
Vaccinium Corymbosum ◽  
Climatic Conditions ◽  
Differentially Expressed ◽  
Transcriptomic Changes ◽  
Go Terms

Blueberries (Vaccinium spp.) are highly vulnerable to changing climatic conditions, especially increasing temperatures. To gain insight into mechanisms underpinning the response to heat stress, two blueberry species were subjected to heat stress for 6 and 9 h at 45 °C, and leaf samples were used to study the morpho-physiological and transcriptomic changes. As compared with Vaccinium corymbosum, Vaccinium darrowii exhibited thermal stress adaptation features such as small leaf size, parallel leaf orientation, waxy leaf coating, increased stomatal surface area, and stomatal closure. RNAseq analysis yielded ~135 million reads and identified 8305 differentially expressed genes (DEGs) during heat stress against the control samples. In V. corymbosum, 2861 and 4565 genes were differentially expressed at 6 and 9 h of heat stress, whereas in V. darrowii, 2516 and 3072 DEGs were differentially expressed at 6 and 9 h, respectively. Among the pathways, the protein processing in the endoplasmic reticulum (ER) was the highly enriched pathway in both the species: however, certain metabolic, fatty acid, photosynthesis-related, peroxisomal, and circadian rhythm pathways were enriched differently among the species. KEGG enrichment analysis of the DEGs revealed important biosynthesis and metabolic pathways crucial in response to heat stress. The GO terms enriched in both the species under heat stress were similar, but more DEGs were enriched for GO terms in V. darrowii than the V. corymbosum. Together, these results elucidate the differential response of morpho-physiological and molecular mechanisms used by both the blueberry species under heat stress, and help in understanding the complex mechanisms involved in heat stress tolerance.

scholarly journals The Effect of Alcohol on Telomere Length: A Systematic Review of Epidemiological Evidence and a Pilot Study during Pregnancy

2021 ◽  
Vol 18 (9) ◽  
pp. 5038
Author(s):  
Andrea Maugeri ◽  
Martina Barchitta ◽  
Roberta Magnano San Lio ◽  
Maria Clara La Rosa ◽  
Claudia La Mastra ◽  
...  
Keyword(s):  
Systematic Review ◽  
Pilot Study ◽  
Alcohol Consumption ◽  
Telomere Length ◽  
Molecular Mechanisms ◽  
Epidemiological Studies ◽  
Potential Association ◽  
Significant Difference ◽  
Periconceptional Period ◽  
Using Data

Several studies—albeit with still inconclusive and limited findings—began to focus on the effect of drinking alcohol on telomere length (TL). Here, we present results from a systematic review of these epidemiological studies to investigate the potential association between alcohol consumption, alcohol-related disorders, and TL. The analysis of fourteen studies—selected from PubMed, Medline, and Web of Science databases—showed that people with alcohol-related disorders exhibited shorter TL, but also that alcohol consumption per se did not appear to affect TL in the absence of alcohol abuse or dependence. Our work also revealed a lack of studies in the periconceptional period, raising the need for evaluating this potential relationship during pregnancy. To fill this gap, we conducted a pilot study using data and samples form the Mamma & Bambino cohort. We compared five non-smoking but drinking women with ten non-smoking and non-drinking women, matched for maternal age, gestational age at recruitment, pregestational body mass index, and fetal sex. Interestingly, we detected a significant difference when analyzing relative TL of leukocyte DNA of cord blood samples from newborns. In particular, newborns from drinking women exhibited shorter relative TL than those born from non-drinking women (p = 0.024). Although these findings appeared promising, further research should be encouraged to test any dose–response relationship, to adjust for the effect of other exposures, and to understand the molecular mechanisms involved.

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