Publications by authors named "Mengiste T"

Article Synopsis
  • Sorghum anthracnose is a severe disease impacting sorghum yields, with resistant varieties being key for effective management.
  • A study evaluated 25 isolates from Ethiopia, revealing significant differences in virulence among them, with certain isolates showing a high degree of pathogenicity.
  • Findings identified specific sorghum genotypes with resistance potential, highlighting the importance of genetic diversity in developing resilient cultivars.
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Article Synopsis
  • Sorghum anthracnose, caused by the fungus Colletotrichum sublineola, significantly affects global sorghum productivity, making the identification and introgression of resistant genotypes imperative for improvement.
  • Field experiments on 358 sorghum accessions in Ethiopia uncovered 53 resistant accessions and 213 with varying resistance to local pathogens, leading to a genome-wide association study (GWAS) identifying 38 genetic loci linked to anthracnose resistance.
  • Notably, specific SNPs associated with genes related to immune responses were identified, suggesting targeted genes for further breeding efforts to enhance resistance in sorghum cultivars.
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Article Synopsis
  • The genetic resources of sorghum in Africa, particularly in Ethiopia, are underutilized for developing new cultivars, despite their potential for local adaptation and improved traits.
  • A study characterized 560 sorghum accessions, using genotyping by sequencing to identify significant genetic diversity, revealing 10 distinct clusters that align with botanical races and ecological types.
  • The findings suggest a strong foundation for hybrid breeding programs by leveraging local germplasm, aiming to enhance productivity and resilience in sorghum cultivars.
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The receptor-like kinase (RLK) family of receptors and the associated receptor-like cytoplasmic kinases (RLCKs) have expanded in plants because of selective pressure from environmental stress and evolving pathogens. RLCKs link pathogen perception to activation of coping mechanisms. RLK-RLCK modules regulate hormone synthesis and responses, reactive oxygen species (ROS) production, Ca signaling, activation of mitogen-activated protein kinase (MAPK), and immune gene expression, all of which contribute to immunity.

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Cancer prevention challenges in Ethiopia include limited community awareness and low uptake of screening, which are in part driven by a lack of culturally and linguistically relevant cancer education appropriate for the diverse indigenous communities of this never-colonized nation. In 2022, a comprehensive multi-media breast cancer (BC) awareness campaign was implemented, featuring local cancer experts and survivors, with community-based screening events in the towns of Adama and Mojo. The RE-AIM framework was used to evaluate and describe its reach, effectiveness, adoption, implementation, and maintenance.

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Article Synopsis
  • Sorghum anthracnose, caused by the fungus Colletotrichum sublineola, is a significant disease affecting sorghum crops, and the study identifies two dominant resistance genes, ARG4 and ARG5, linked to this disease.
  • Both genes encode for NLR receptors and were found in sorghum lines SAP135 and P9830, exhibiting broad-spectrum resistance to various strains of the fungus.
  • Genetic mapping and comparative genomics reveal that ARG4 and ARG5 are within clusters of duplicate NLR genes, suggesting a complex genetic relationship with potential implications for future breeding and resistance studies.
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Sorghum is an important food and feed crop globally; its production is hampered by anthracnose disease caused by the fungal pathogen Colletotrichum sublineola (Cs). Here, we report identification and characterization of ANTHRACNOSE RESISTANCE GENE 2 (ARG2) encoding a nucleotide-binding leucine-rich repeat (NLR) protein that confers race-specific resistance to Cs strains. ARG2 is one of a cluster of several NLR genes initially identified in the sorghum differential line SC328C that is resistant to some Cs strains.

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Histone posttranslational modifications shape the chromatin landscape of the plant genome and affect gene expression in response to developmental and environmental cues. To date, the role of histone modifications in regulating plant responses to environmental nutrient availability, especially in agriculturally important species, remains largely unknown. We describe the functions of two histone lysine methyltransferases, SET Domain Group 33 (SDG33) and SDG34, in mediating nitrogen (N) responses of shoots and roots in tomato.

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Botrytis cinerea, a widespread plant pathogen with a necrotrophic lifestyle, causes gray mold disease in many crops. Massive secretion of enzymes and toxins was long considered to be the main driver of infection, but recent studies have uncovered a rich toolbox for B. cinerea pathogenicity.

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Pathogenesis in plant diseases is complex comprising diverse pathogen virulence and plant immune mechanisms. These pathogens cause damaging plant diseases by deploying specialized and generic virulence strategies that are countered by intricate resistance mechanisms. The significant challenges that necrotrophs pose to crop production are predicted to increase with climate change.

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Histone lysine methylations (HLMs) are implicated in control of gene expression in different eukaryotes. However, the role of HLMs in regulating desirable crop traits and the enzymes involved in these modifications are poorly understood. We studied the functions of tomato histone H3 lysine methyltransferases SET Domain Group 33 (SDG33) and SDG34 in biotic and abiotic stress responses.

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Sorghum (Sorghum bicolor), the fifth most widely grown cereal crop globally, provides food security for millions of people. Anthracnose caused by the fungus Colletotrichum sublineola is a major disease of sorghum worldwide. We discovered a major fungal resistance locus in sorghum composed of the nucleotide-binding leucine-rich repeat receptor gene ANTHRACNOSE RESISTANCE GENE1 (ARG1) that is completely nested in an intron of a cis-natural antisense transcript (NAT) gene designated CARRIER OF ARG1 (CARG).

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Article Synopsis
  • The study investigates the roles of a tomato protein called TRK1 in providing quantitative resistance to fungal pathogens and its impact on plant growth.
  • TRK1 interacts with another protein, SlLYK1, to facilitate immune responses against fungal infections and manage hormone signaling related to plant development.
  • The findings show that while TRK1 enhances resistance in leaves, it has an opposing effect in meristem areas, indicating a complex relationship between plant defense mechanisms and growth processes.
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Background: Sorghum grain mold is the most important disease of the crop. The disease results from simultaneous infection of the grain by multiple fungal species. Host responses to these fungi and the underlying molecular and cellular processes are poorly understood.

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Crh proteins catalyze crosslinking of chitin and glucan polymers in fungal cell walls. Here, we show that the BcCrh1 protein from the phytopathogenic fungus Botrytis cinerea acts as a cytoplasmic effector and elicitor of plant defense. BcCrh1 is localized in vacuoles and the endoplasmic reticulum during saprophytic growth.

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GWAS analysis revealed variations at loci harboring seed storage, late embryogenesis abundant protein, and a tannin biosynthesis gene associated with sorghum grain mold resistance. Grain mold is the most important disease of sorghum [Sorghum bicolor (L.) Moench].

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Crop domestication events followed by targeted breeding practices have been pivotal for improvement of desirable traits and to adapt cultivars to local environments. Domestication also resulted in a strong reduction in genetic diversity among modern cultivars compared to their wild relatives, though the effect this could have on tripartite relationships between plants, belowground beneficial microbes and aboveground pathogens remains undetermined. We quantified plant growth performance, basal resistance and induced systemic resistance (ISR) by , a beneficial soil microbe against , a necrotrophic fungus and , a hemi-biotrophic oomycete, in 25 diverse tomato genotypes.

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Understanding population genetic structure and diversity of a crop is essential in designing selection strategies in plant breeding. About 2010 Ethiopian sorghum accessions were phenotyped for different traits at multiple locations. A subset of the collection, 1628 accessions, predominantly landraces, some improved varieties, and inbred lines were genotyped by sequencing.

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Background: Anthracnose is a damaging disease of sorghum caused by the fungal pathogen Colletotrichum sublineolum. Genome-wide mRNA and microRNA (miRNA) profiles of resistant and susceptible sorghum genotypes were studied to understand components of immune responses, and fungal induced miRNA and target gene networks.

Results: A total of 18 mRNA and 12 miRNA libraries from resistant and susceptible sorghum lines were sequenced prior to and after inoculation with C.

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Fungal endophytes can influence production and post-harvest challenges in carrot, though the identity of these microbes as well as factors affecting their composition have not yet been determined, which prevents growers from managing these organisms to improve crop performance. Consequently, we characterized the endophytic mycobiome in the taproots of three carrot genotypes that vary in resistance to two pathogens grown in a trial comparing organic and conventional crop management using Illumina sequencing of the internal transcribed spacer (ITS) gene. A total of 1,480 individual operational taxonomic units (OTUs) were identified.

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CDK8 is a key subunit of Mediator complex, a large multiprotein complex that is a fundamental part of the conserved eukaryotic transcriptional machinery. However, the biological functions of CDK8 in plant abiotic stress responses remain largely unexplored. Here, we demonstrated CDK8 as a critical regulator in the abscisic acid (ABA) signaling and drought response pathways in Arabidopsis.

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Managing pests in carrot production is challenging. Endophytic microbes have been demonstrated to improve the health and productivity of many crops, but factors affecting endophyte dynamics in carrot is still not well understood. The goal of this study was to determine how crop management system and carrot genotype interact to affect the composition and potential of endophytes to mitigate disease caused by Alternaria dauci, an important carrot pathogen.

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The eastern Africa region, Ethiopia and its surroundings, is considered as the center of origin and diversity for sorghum, and has contributed to global sorghum genetic improvement. The germplasm from this region harbors enormous genetic variation for various traits but little is known regarding the genetic architecture of most traits. Here, 1425 Ethiopian landrace accessions were phenotyped under field conditions for presence or absence of awns, panicle compactness and shape, panicle exsertion, pericarp color, glume cover, plant height and smut resistance under diverse environmental conditions in Ethiopia.

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NPR1 (NONEXPRESSER OF PR GENES1) functions as a master regulator of the plant hormone salicylic acid (SA) signaling and plays an essential role in plant immunity. In the nucleus, NPR1 interacts with transcription factors to induce the expression of (-) genes and thereby promote defense responses. However, the underlying molecular mechanism of gene activation is poorly understood.

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