Biology subjects

Gill, B. S.

Publications and source records attributed to Gill, B. S..

5 recordsLinked to original sources

bioRxiv2023

The International Weed Genomics Consortium: Community Resources for Weed Genomics Research

The International Weed Genomics Consortium is a collaborative group of researchers focused on developing genomic resources for the study of weedy plants. Weeds are attractive systems for basic and applied research due to their impacts on agricultural systems and capacity to swiftly adapt in response to anthropogenic selection pressures. Our goal is to use genomic information to develop sustainable and effective weed control methods and to provide insights about biotic and abiotic stress tolerance to assist crop breeding. Here, we outline resources under development by the consortium and highlight areas of research that will be impacted by these enabling resources.

genomics↗

bioRxiv2023

The eccDNA mediated spread and rapid evolution of herbicide resistance in pigweed interspecific hybrids

Extrachromosomal circular DNAs (eccDNAs) are found in many eukaryotic organisms. The eccDNA-powered copy number variation plays diverse roles from oncogenesis in humans to herbicide resistance in crop weeds. Here we report interspecific eccDNA flow and its dynamic behavior in soma cells of natural populations and F1 hybrids of Amaranthus sp. The glyphosate resistance (GR) trait is controlled by eccDNA-based amplification harboring the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene (EPSPS-eccDNA), the molecular target of glyphosate. We documented pollen-mediated transfer of eccDNA in experimental hybrids between GS A. tuberculatus x GR A. palmeri. Experimental hybridization and fluorescence in situ hybridization (FISH) analysis revealed that the EPSPS-eccDNA present in A. spinosus was derived from GR A. palmeri by natural hybridization. FISH analysis also revealed random chromosome anchoring and massive EPSPS-eccDNA copy number variation in soma cells of weedy hybrids. The results suggest that eccDNAs are inheritable across compatible species contributing to genome plasticity and rapid adaptive evolution.

genetics↗

bioRxiv2020

Discovery of a Promising Susceptibility Factor for Fusarium Head Blight in Wheat

Fusarium head blight (FHB) disease of wheat caused by Fusarium spp. deteriorates both quantity and quality of the crop. Manipulation of susceptibility factors, the genes facilitating disease development in plants, offers a novel and alternative strategy for enhancing FHB resistance in plants. In this study, a major effect susceptibility gene for FHB was identified on the short arm of chromosome 7A (7AS). Nullisomic-tetrasomic lines for homoeologous group-7 of wheat revealed dosage effect of the gene, with tetrasomic 7A being more susceptible than control Chinese Spring wheat, qualifying it as a bonafide susceptibility factor. The gene locus was conserved in six chromosome 7A inter-varietal wheat substitution lines of diverse origin and a tetraploid Triticum dicoccoides genotype. The susceptibility gene was named as SF7ASFHB and mapped on chromosome 7AS to 48.5-50.5 Mb peri-centromeric region between del7AS-3 and del7AS-8. Our results showed that deletion of SF7ASFHB imparts ~ 50-60% type 2 FHB resistance (against the spread of the fungal pathogen) and its manipulation may lead to enhanced resistance against FHB in wheat. HighlightDiscovery and mapping of a conserved susceptibility factor located on the short arm of wheat chromosome 7A whose deletion makes plants resistant to Fusarium Head Blight.

genetics↗

bioRxiv2020

Modeling the Impact of Lock-down on COVID-19 Spread in Malaysia

After a breakdown notified in Wuhan, China in December 2019, COVID-19 is declared as pandemic diseases. To the date more than 13 million confirmed cases and more than half a million are dead around the world. This virus also attached Malaysia in its immature stage where 8718 cases were confirmed and 122 were declared as death. Malaysia responsibly controlled the spread by enforcing MCO. Hence, it is required to visualize the pattern of Covid-19 spread. Also, it is necessary to estimate the impact of the enforced prevention measures. In this paper, an infectious disease dynamic modeling (SEIR) is used to estimate the epidemic spread in Malaysia. The main assumption is to update the reproduction number Rt with respect to the implemented prevention measures. For a time-frame of five month, the Rt was assumed to vary between 2.9 and 0.3. Moreover, the manuscript includes two possible scenarios: the first will be the extension of the stricter measures all over the country, and the second will be the gradual lift of the lock-down. After implementing several stages of lock-down we have found that the estimated values of the Rt with respect to the strictness degree varies between 0.2 to 1.1. A continuous strict lock-down may reduce the Rt to 0.2 and accordingly the estimated active cases will be reduced to 20 by the beginning of September 2020. In contrast, the second scenario considers a gradual lift of the enforced prevention measures by the end of June 2020, here we have considered three possible outcomes according to the MCO relaxation. Thus, the estimated values of Rt = 0.7, 0.9, 1.1, which shows a rapid increase in the number of active cases. The implemented SEIR model shows a close resemblance with the actual data recorded from 10, March till 7, July 2020. Author summaryConceptualization, A.A.A; methodology, A.A.A, N.M; validation, A.A.A, N.M; formal analysis, A.A.A; investigation, N.M, A.A.A; resources, G.E.M.A, L.T; data collection, L.T, N.M; writing--original draft preparation, A.A.A, L.T, G.E.M.A, N.M; writing--review and editing, V.S.A, S.C.D, B.S.G, P.S, S.A.B.M.Z, N.M; visualization, N.M; supervision, V.S.A; project administration, V.S.A. All authors have read and agreed to the published version of the manuscript

bioinformatics↗

bioRxiv2019

Establishment of Wolbachia strain wAlbB in Malaysian populations of Aedes aegypti for dengue control

Dengue has enormous health impacts globally. A novel approach to decrease dengue incidence involves the introduction of Wolbachia endosymbionts that block dengue virus transmission into populations of the primary vector mosquito, Aedes aegypti. The wMel Wolbachia strain has previously been trialed in open releases of Ae. aegypti; however the wAlbB strain has been shown to maintain higher density than wMel at high larval rearing temperatures. Releases of Ae. aegypti mosquitoes carrying wAlbB were carried out in 6 diverse sites in greater Kuala Lumpur, Malaysia, with high endemic dengue transmission. The strain was successfully established and maintained at very high population frequency at some sites, or persisted with additional releases following fluctuations at other sites. Based on passive case monitoring, reduced human dengue incidence was observed in the release sites when compared to control sites. The wAlbB strain of Wolbachia provides a promising option as a tool for dengue control, particularly in very hot climates.

microbiology↗