Browsing by Author "Masika, Fred Bwayo"
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Item First report of Moroccan watermelon mosaic virus and other viruses infecting watermelon (Citrullus lanatus) in Uganda(New Disease Report, 2025-05-15) Masika, Fred Bwayo; Mahipal, S. K.; Alicai, T.; Shimelis, H.; Ddamulira, G.; Athman, S. Y.; Ipulet, P.; Osingada, F.; Salman, F. A.; Tugume, A. K.This study reports the first detection of Moroccan watermelon mosaic virus (MWMV) and multiple other viruses infecting watermelon (Citrullus lanatus) in Uganda. Using high-throughput sequencing of leaf samples collected from commercial farms across three districts, we identified six viruses, including MWMV, pepo aphid-borne yellows virus (PABYV), Citrullus lanatus cryptic virus, Cucumis melo cryptic virus, Watermelon crinkle leaf-associated virus, and a novel E. coli virus. The complete genome sequences of MWMV and PABYV were obtained, and virus presence was confirmed through RT-PCR. Observations indicated that mixed infections led to more severe symptoms such as mosaic patterns, leaf mottling, and stunting, affecting approximately 30–40% of cultivated plants. These findings underscore the emerging viral challenges in Ugandan watermelon production and emphasize the importance of vigilant disease monitoring and management strategies.Item Genome-wide analysis of the pleiotropic drug resistance (PDR) gene family and putative PDR specific miRNAs: deciphering their functions in development processes and varied stresses in Triticum aestivum L.(Springer Nature, 2026-01-13) Kesawat, Mahipal Singh; Kherawat, Bhagwat Singh; Reager, Madan Lal; Lenka, Sangram K.; Chung, Sang-Min; Masika, Fred BwayoBackground The pleiotropic drug resistance (PDR) transporter stands out as one of the largest subfamilies within ABC transporters. These transporters play crucial roles in a multitude of biological processes, including detoxification, phytohormone transportation, stomatal movement, the translocation of various secondary metabolites, tolerance to heavy metal and adaptation to the diverse stress conditions. However, the structural and functional characterization of PDR gene family members in wheat has yet to be fully elucidated. Results In this investigation, we identified 66 TaPDR genes in the genome of wheat. The subsequent phylogenetic tree revealed that the genes clustered into four subfamilies. Chromosomal mapping unveiled the dispersal of 66 TaPDR genes across 17 wheat chromosomes. The twenty-two pairs of duplicated gene were identified in the PDR family. Ka/Ks ratio revealed that 22 duplicated TaPDR genes went through purifying selection. It was noted that the TaPDR genes displayed significant diversity in their gene structures. In addition, the presence of numerous cis-regulatory elements in the promoter regions of the TaPDR genes were identified. Differential expression patterns were observed among TaPDR family members across various tissues and in response to multiple stress conditions. Moreover, this investigation explored the miRNAs targeting TaPDR genes and their expression profiles in various tissues. Conclusion Thus, the results of this study establish a strong basis for further investigation of the functions of TaPDR genes across different tissues, developmental stages, phytohormone responses, and diverse stress in wheat.Item Genome-wide identification and expression analysis of the Small Ubiquitin-like Modifier (SUMO) gene family in Triticum aestivum L.(Springer Nature, 2025-12-11) Kesawa, Mahipal Singh; Kherawat, Bhagwat Singh; Reager, Madan Lal; Badu, Meenakshi; Kabi, Mandakini; Mohanty, Ankita; Raju, Kalidindi Krishnam; Lenka, Sangram K.; Alamery, Salman Freeh; Al-ateeq, Talak K.; Masika, Fred Bwayo; Hong, Choo BongBackground: Post-translational modification of proteins by SUMO is critical for a wide range of cellular and developmental processes. Although SUMO proteins have been extensively studied in animals and, to some extent, in Arabidopsis, their precise functions in other crop plants are still largely unknown. Results: In this research, we identified 31 TaSUMO genes in genome of wheat. Phylogenetic tree unveiled that genes clustered into thirteen subfamilies. Chromosomal mapping unveiled the dispersal of 31 TaSUMO genes across 11 wheat chromosomes. The eleven pairs of duplicated gene were identified in the SUMO family. Ka/Ks ratio revealed that 8 duplicated TaSUMO genes went through purifying purification. Furthermore, it was noted that TaSUMO genes displayed significant conversation in their gene structure. In addition, analysis of promoters uncovered the presence of numerous cis-regulatory elements in the promoter region of the TaSUMO genes. The differential expression patterns were observed among TaSUMO family members across various tissues and in response to multifaceted stress conditions. Moreover, this investigation explored the miRNAs targeted to TaSUMO genes and expression profile in various tissues. Conclusion: Thus, the results of this study establish a strong basis for further investigation of the functions of TaSUMO genes across different tissues, developmental stages, phytohormone responses, and diverse stress in wheat.Item Genome-wide survey and expression analysis of peptides containing tyrosine sulfation (PSY) gene family in Cicer arietinum L.(Springer Nature, 2026-02-21) Kesawat, Mahipal Singh; Kumar, Vinay; Manohar, Swati; Sohail, Aqib; Rani, Manjusha; Chung, Sang-Min; Kumar, Deepak; Lenka, Sangram K.; Masika, Fred BwayoBackground Plant growth and developmental processes are tightly regulated by small secreted peptides, however, the functions and mechanisms of Tyrosine Sulfation-containing Peptides (PSY) remain unclear. In chickpea, knowledge of PSY genes family is limited. Results This study employed comprehensive bioinformatics approaches to identify and characterize seven CaPSY genes in the chickpea genome. The analyses encompass chromosomal localization, evolutionary relationships, gene structure, conserved motif identification, promoter architecture, prediction of PSY-targeting miRNAs, and expression profiling. Chromosomal mapping revealed that CaPSY genes are confined to four specific chromosomes rather than being evenly distributed across the genome. Phylogenetic analysis resolved nine distinct groups, each further subdivided into subgroups. Additionally, CaPSY genes were found to contain one to two introns. Amino acid sequence comparisons demonstrated that each CaPSY gene consistently harbors a PSY domain in its C-terminal end. Promoter analysis of CaPSY genes revealed the presence of multiple hormone-responsive elements, including ABRE, SARE, AuxRE, and MeJARE, as well as stress-related elements such as the drought-responsive MBS, suggesting potential regulatory roles in development and stress adaptation. Further, the expression patterns of CaPSY were evaluated in multiple tissues as well as in response to abiotic stresses. The results indicated differential expression of CaPSY genes among tissues and under multiple abiotic stress conditions. We further detected several miRNAs likely to target CaPSY genes and assessed how they are expressed in different tissues. Conclusion Thus, these findings serve as a crucial resource for basic and applied research, enabling advancements in chickpea productivity and stress tolerance via precise genome editing and innovative breeding methods.Item Genome-wide survey of peptides containing tyrosine sulfation (PSY) gene family and potential PSY specific miRNA revealed their role in plant development and diverse stress conditions in rice (Oryza sativa L.).(Springer Nature, 2025-08-26) Kesawat, Mahipal Singh; Manohar, Swati; Anand, Ankit; Alamery, Salman Freeh; Badu, Meenakshi; Kabi, Mandakini; Mohanty, Ankita; Naik, Islavath Suresh; Kumar, Santosh; Kherawat, Bhagwat Singh; Kumar, Vinay; Lenka, Sangram K.; Verma, Shreya; Shrivastava, Harsha; Kumawat, Giriraj; Masika, Fred BwayoBackground Soybean is a fundamental oilseed crop, recognized for its notable protein and oil levels. Tyrosine Sulfation (PSY) genes play an essential role in plant growth, development, and responses to stress. However, the precise functions and mechanisms regulated by PSY are still being explored. Currently, there is insufficient information on the PSY gene family in soybean. Therefore, this study conducted a comprehensive genome-wide survey to detect and PSY family members were categorized in soybean. Results The phylogenetic analysis revealed that PSY family was categorized into nine distinct groups. Further, we precisely mapped the locations of the 12 GmPSY genes across seven soybean chromosomes. Examination of gene duplication revealed six pairs of duplicated genes within the PSY gene family in soybean. A consistent gene structure pattern was observed among GmPSY gene family members. The alignment of GmPSY protein amino acid sequences revealed a conserved PSY domain present in all proteins. Furthermore, RNA-seq data from the Soybean Expression Atlas revealed varying expression patterns of GmPSY genes across different tissues. To validate the expression profiles, qRT-PCR analysis was performed on selected GmPSY genes using root tissues from contrasting soybean accessions. In addition, identified eight out of the 12 GmPSY genes as targets for ten specific miRNAs. Moreover, we constructed a protein-protein interaction network to explore the connections between GmPSY and other soybean proteins. Conclusion Thus, these discoveries lay a robust groundwork for future research aimed at elucidating the specific roles of GmPSY members across different tissues and under various stress conditions in soybean.Item High-throughput sequencing analysis reveals Moroccan Watermelon Mosaic Virus and Tobacco Streak Virus isolates infecting pumpkins in Uganda(CABI Agriculture and Bioscience, 2025-08-01) Masika, Fred Bwayo; Tugume, Arthur K.; Kesawat, Mahipal S.; Shimelis, Hussein; Ddamulira, Gabriel; Athman, Shahasi Y.; Ipulet, Perpetua; Alicai, TitusPumpkin (Cucurbita pepo L.) is a globally cultivated, economically significant cucurbit species, yet viral diseases pose a major threat to its yield and quality, especially in key production areas such as Uganda. To investigate and document viruses affecting pumpkins in Uganda, we assessed the sub-regional severity of virus-like diseases and identified pumpkin-infecting viruses using RNA sequencing. A total of 75 pumpkin leaf samples displaying typical viral symptoms were collected from 66 fields across Uganda. These samples were then pooled into five bulk groups, each consisting of 15 different plant leaves. Our analysis identified two viruses and detected six viruses, which were, however, not confirmed by another method. The two identified viruses were Moroccan Watermelon Mosaic Virus (MWMV) and Tobacco Streak Virus (TSV). This is the first report of MWMV and TSV infecting pumpkins in Uganda. The virus-like disease symptoms exhibited variations in sub-regional severity and incidence. These findings highlight the current viral diversity in pumpkins in Uganda, providing critical information for developing integrated disease management strategies to enhance crop yield and productivity.Item Nanoparticles in plant system: A comprehensive review on their role in diverse stress management and phytohormone signaling(Elsevier, 2025-08-19) Kumar, Vinay; Naik, Islavath Suresh; Das, Bimal; Singh, Anupama; Nayak, Prayasi; Mohapatra, Chinmayee; Debnath, Debanjana; Tripathy, Maitreyee; Behera, Kumareswar; Masika, Fred Bwayo; Manohar, Swati; Chung, Sang-Min; Kherawat, Bhagwat Singh; Hemalatha, Mamidi; Kesawat, Mahipal SinghClimate variability has led to significant environmental shifts in recent years, placing growing strain on agricultural systems worldwide. These environmental fluctuations have magnified the effects of abiotic and biotic stresses on plants, substantially hampering their growth and lowering crop productivity. To tackle these challenges, there is an urgent need for innovative and effective strategies that promote sustainable agricultural practices. Among emerging technologies, nanotechnology has attracted significant interest for its transformative potential in agriculture. The application of nanoscale materials including nanopesticides, nanofungicides, nanofertilizers, and nanoherbicides offers promising avenues for enhancing crop protection and boost productivity. Nanoparticles (NPs) exhibit unique physicochemical properties that allow for precise and targeted delivery of nutrients and protective agents, thereby improving both the quality and yield of crops under diverse stress conditions. Phytohormone signaling pathways comprise intricate biochemical networks that enable plant hormones to regulate growth, development, and stress responses by transmitting and amplifying precise molecular signals. Recent studies suggest that NPs can alleviate stress-induced damage in plants by modulating phytohormone signaling pathways. However, the complex mechanisms underlying the interactions between NPs and phytohormone biosynthesis remain largely unexplored. This review offers a comprehensive overview of nanoparticle synthesis methods, types, and characterization techniques, with particular emphasis on their potential for mitigating both abiotic and biotic stresses. In addition, the article explores the role of NPs in plant pathology, particularly in disease detection and management. It also highlights emerging evidence on the impact of NPs on phytohormone signaling pathways, which are crucial for improving plant resilience and productivity in stress-prone environments. Thus, nanotechnology holds considerable promise for alleviating stress-related challenges and improving crop yields. A deeper understanding of NP–phytohormone interactions is crucial for developing safe and effective nanotechnological strategies to advance sustainable agricultureItem Relative abundance, geographical distribution, and utilization of the edible wild black plum (Vitex doniana) in Uganda(Springer Nature, 2025-08-04) Caku, Jimmy; Kesawat, Mahipal S.; Ddamulira, Gabriel; Masika, Fred BwayoWild edible plants play a crucial role in food security, biodiversity conservation, and sustaining rural livelihoods. Vitex doniana, though widely distributed, remains an underutilized species with significant ecological, economic, and medicinal value. Despite its adaptability across diverse ecosystems, its population in Uganda faces increasing threats from human activities. In addition, the lack of comprehensive data on its abundance and distribution hampers conservation efforts, posing a risk to the plant’s genetic diversity. Ecological and ethnobotanical surveys were conducted in Uganda, Koboko district, to assess the abundance, utilization, and distribution of V. doniana. A total of six line transects and 18 quadrats (three alternating quadrats (50 m × 100 m) with 25 m spacing between quadrats per line transect) were used for data collection. A pre-tested questionnaire was used to collect data on the utilisation of V. doniana from 144 respondents. Data were analysed using descriptive statistics and Chi-square tests in SPSS. Results indicated a higher relative abundance of young regenerating trees (74.0%) than mature trees (26.0%). The distribution of V. doniana across different land-use types showed a statistically significant variation (χ² = 7.17, df = 2, p = 0.028). The local community utilizes the tree for fruit harvesting, firewood, charcoal production, and construction purposes. To ensure the sustainable use of V. doniana, community by-laws, awareness, controlled harvesting, and agroforestry practices should be embraced.Item Seasonal dynamics of Elaeidobius Kamerunicus in allopatric populations: comparative analysis from indigenous mainland and introduced oil palm ecosystems in Uganda’s lake Victoria islands(Taylor & Francis, 2026-02-04) Masika, Fred Bwayo; Otuba, Amugoli Moses; Kesawat, Mahipal Singh; Asiimwe, Alex; Baguma, Bidget; Alicai, Titus; Manohar, Swati; Ddamulira, GabrielOil palm (Elaeis guineensis L.), native to Africa but widely cultivated in Southeast Asia, is increasingly grown in Uganda, and pollination efficiency is critical for fruit set and oil yield. The study assessed the population and sexual diversity of the primary pollinator, Elaeidobius kamerunicus FAUST, in introduced hybrid plantations in Kalangala and natural stands in Bundibugyo. Pollinator weevils were sampled across both wet and dry seasons in 2022 and 2023, and data were analyzed using ANOVA and correlation tests in Minitab 17. Results revealed significant variation between sites, with higher populations in Kalangala (7,503 ± 8.682) compared to Bundibugyo (5,164 ± 5.829). Furthermore, females (6,636 ± 4.646) outnumbered males (6,032 ± 5.028), with a slightly higher concentration of females in the middle section of male inflorescences. Seasonal differences were evident, as the wet season supported slightly higher weevil populations relative to the dry season. Correlation analysis indicated a weak negative relationship between weevil abundance and weather variables, suggesting that cooler conditions suppress population growth. Overall, Uganda provides favorable conditions for pollinator weevil multiplication, particularly under moist climatic regimes, while extensive cold conditions limit population expansion. These findings highlight the importance of pollinator dynamics in sustaining oil palm productivity in diverse agroecological regions.Item Trading tomatoes and onions in Uganda’s watersheds: actors, dynamics, and opportunities(Canadian Center of Science and Education, 2026-01-15) Masika, Fred Bwayo; Ddamulira, Gabriel; Obongo, Isaac; Aropet, Stella Adumo; Asiimwe, Alex; Kiryowa, Moses; Logose, Maureen; Amugoli, Otuba Moses; Naluyimba, Rehema; Ramathan, IddHorticulture accounts for more than half of Uganda’s agricultural output, yet crops such as tomatoes and onions remain only marginally profitable despite the country’s favorable climate. To assess the state of their marketing, a study was conducted across five watershed irrigation schemes of Ngenge, Tochi, Wadelai, Mubuku II, and Doho. Researchers interviewed 56 key informants and 174 market vendors using questionnaires that explored market actors, their roles and interconnections, seasonal trade dynamics, pricing, supply and demand, gross margins, and both opportunities and constraints. Data were analyzed using Microsoft Excel and SPSS. The findings showed that nearly half of the markets (46%) were underdeveloped, with women and youth making up the majority of vendors (78%). Farmers were the main suppliers, but often overlapped with other market roles. Seasonal fluctuations affected tomato and onion availability, with oblong tomato varieties being most popular. Key challenges included poor storage facilities, high market fees, and price volatility. However, strong local demand, access to export channels, and opportunities for off-season production highlight promising avenues for improving the profitability and sustainability of tomato and onion marketing in Uganda.Item Unexplored potential of carrot (Daucus carota L.) bioactive in combating cancer: an insight into intricate mechanisms(Taylor & Francis, 2026-01-27) Kumar, Santosh; Kesawat, Mahipal Singh; Kherawat, Bhagwat Singh; Singh, Archana; Kumar, Anmol; Kumari, Sweta; Alamery, Salman Freeh; Singh, Pratibha; Masika, Fred Bwayo; Manohar, SwatiThe rising incidence of cancer, combined with costs, toxicity, and side effects of conventional treatments such as immunotherapy, chemotherapy, radiotherapy, and surgery, underscores the need for preventive strategies. Natural phyto-bioactives, have attracted increasing scientific interest due to their diverse biological activities. These phytochemicals in carrots have been studied for their roles in modulating intracellular signalling pathways in vitro and preclinical studies. Carrots contain an abundant spectrum of bioactive compounds, including phenolics, carotenoids, polyacetylenes, ascorbic acid, and dietary fiber. These constituents have been reported to modulate processes such as apoptosis, oxidative stress, inflammation, angiogenesis, and pathways involved in cell proliferation in experimental systems. This comprehensive review studies findings from preclinical studies, epidemiological research, and meta-analyses to evaluate the biological activities of carrot bioactives in cancer-relevant biological mechanisms. By examining their ability to modulate molecular pathways involved in tumour invasion and metastasis, this review highlights the potential mechanistic relevance of carrot-derived phytoactive compounds against metastatic cells. Although preclinical studies suggest that these bioactives may influence processes associated with tumour progression, the available evidence is largely derived from in vitro and animal models, and therefore requires validation through translational research and well-designed, large-scale clinical trials. Rather than establishing definitive cancer-preventive or therapeutic effects, current scientific findings support the role of carrot-derived bioactives as promising candidates for further investigation. Advancing research into the underlying molecular mechanisms of carrots may help identify specific phytochemicals that modulate pathways related to tumour invasion and metastasis, therby enabling the development of future cancer prevention strategies.Item Unraveling the genetic basis of fertility restoration in hybrid rice: insights from CMS lines and male restorer analyses(Taylor & Francis, 2025-10-21) Sharmaa, Deepak D.; Patel, V. P.; Chaudhary, Ankit; Modha, K.G.; Parekh, V.B.; Naik, Islavath Suresh; Masika, Fred Bwayo; Kesawat, Mahipal SinghRice (Oryza sativa L.) serves as the staple food for over half of the global population. To address the pressing need for increased rice production, hybrid rice technology leverages the concept of hybrid vigor, or heterosis, achieving a 15–20% yield advantage over traditional varieties. This study focuses on developing hybrid varieties through the cytoplasmic genetic male sterility (CGMS) mechanism. It explores the genetic inheritance of fertility restoration in two distinct CMS lines, IR58025A (WA) and RTN13A (Gambiaca), using 165 diverse male lines. The study successfully generated F1 hybrids and evaluated them for pollen and spikelet fertility, identifying NVSR 2965 and NVSR 3280 as effective restorers, with fertility rates surpassing 90%. Analysis of the F2 generations from these crosses revealed that fertility restoration is controlled by two dominant genes, Rf3 and Rf4, which interact epistatically. The cross IR58025A × NVSR 2965 exhibited a 12:3:1 segregation pattern, suggesting simple dominance with a masking effect, while RTN13A × NVSR 3280 showed a 15:1 ratio, indicating duplicate dominance. These findings enhance our understanding of the genetic mechanisms underlying fertility restoration and provide valuable insights for applying marker-assisted selection and breeding strategies to develop high-yield hybrid rice varieties.