Publications by authors named "Omid Ansari"

6 Publications

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An extreme-phenotype genome-wide association study identifies candidate cannabinoid pathway genes in Cannabis.

Sci Rep 2020 10 29;10(1):18643. Epub 2020 Oct 29.

Southern Cross Plant Science, Southern Cross University, Lismore, NSW, 2480, Australia.

Cannabis produces a class of isoprenylated resorcinyl polyketides known as cannabinoids, a subset of which are medically important and exclusive to this plant. The cannabinoid alkyl group is a critical structural feature that governs therapeutic activity. Genetic enhancement of the alkyl side-chain could lead to the development of novel chemical phenotypes (chemotypes) for pharmaceutical end-use. However, the genetic determinants underlying in planta variation of cannabinoid alkyl side-chain length remain uncharacterised. Using a diversity panel derived from the Ecofibre Cannabis germplasm collection, an extreme-phenotype genome-wide association study (XP-GWAS) was used to enrich for alkyl cannabinoid polymorphic regions. Resequencing of chemotypically extreme pools revealed a known cannabinoid synthesis pathway locus as well as a series of chemotype-associated genomic regions. One of these regions contained a candidate gene encoding a β-keto acyl carrier protein (ACP) reductase (BKR) putatively associated with polyketide fatty acid starter unit synthesis and alkyl side-chain length. Association analysis revealed twenty-two polymorphic variants spanning the length of this gene, including two nonsynonymous substitutions. The success of this first reported application of XP-GWAS for an obligate outcrossing and highly heterozygote plant genus suggests that this approach may have generic application for other plant species.
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http://dx.doi.org/10.1038/s41598-020-75271-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7596533PMC
October 2020

Multi-functionPlantDefensin,AntimicrobialandHeavyMetal Adsorbent Peptide.

Iran J Biotechnol 2019 Sep 1;17(3):e1562. Epub 2019 Sep 1.

Ecofibre Industries Operations and Ananda Hemp, Brisbane, Australia.

Background: Defensin peptide isolated from plants are often heterogeneous in length, sequence and structure, but they are mostly small, cationic and amphipathic. Plant defensins exhibit broad-spectrum antibacterial and antifungal activities against Gram-positive and Gram-negative bacteria, fungi and etc. Plant defensins also play an important role in innate immunity, such as heavy metal and some abiotic stresses tolerance.

Objectives: In this paper, broad-spectrum activities, antimicrobial and heavy metal absorption, of a recombinant plant defensin were studied.

Material And Methods: gene, a modified plant defensin gene, was cloned in pBISN1-IN (EU886197) plasmid, recombinant protein was produced by transient expression via Agroinfiltration method in common bean. The recombinant protein was tested for antibacterial activity against Gram-negative, Gram-positive bacteria and Fusarium sp. the effects of different treatments on heavy metal zinc absorption by this peptide were tested.

Results: We confirmed the antibacterial activities of this peptide against Gram-negative ( and ) and Gram-positive ( and ) bacteria, and antifungal activities of this peptide against Fusarium spp. ( and ). High metal absorption coefficient for this peptide was also observed.

Results: Out of six actinobacterial isolates, VITVAMB 1 possessed the most efficient RO-16 decolorization property. It decolorized 85.6% of RO-16 (250 mg L) within 24hrs. Isolate VITVAMB 1 was identified to be sp. Maximum dye decolorization occurred at pH 8, temperature 35oC, 3% salt concentration and a dye concentration of 50 mg L.

Conclusions: Results suggesting that modified defensin peptide facilitates a broader range of defense activities. dedefensins are an important part of the innate immune system in eukaryotes. These molecules have multidimensional properties that making them promising agents for therapeutic drugs.
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http://dx.doi.org/10.29252/ijb.1562DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7080970PMC
September 2019

Complex Patterns of Cannabinoid Alkyl Side-Chain Inheritance in Cannabis.

Sci Rep 2019 08 6;9(1):11421. Epub 2019 Aug 6.

Southern Cross Plant Science, Southern Cross University, Lismore, New South Wales, 2480, Australia.

The cannabinoid alkyl side-chain represents an important pharmacophore, where genetic targeting of alkyl homologs has the potential to provide enhanced forms of Cannabis for biopharmaceutical manufacture. Delta(9)-tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA) synthase genes govern dicyclic (CBDA) and tricyclic (THCA) cannabinoid composition. However, the inheritance of alkyl side-chain length has not been resolved, and few studies have investigated the contributions and interactions between cannabinoid synthesis pathway loci. To examine the inheritance of chemical phenotype (chemotype), THCAS and CBDAS genotypes were scored and alkyl cannabinoid segregation analysed in 210 F progeny derived from a cross between two Cannabis chemotypes divergent for alkyl and cyclic cannabinoids. Inheritance patterns of F progeny were non-Gaussian and deviated from Mendelian expectations. However, discrete alkyl cannabinoid segregation patterns consistent with digenic as well as epistatic modes of inheritance were observed among F THCAS and CBDAS genotypes. These results suggest linkage between cannabinoid pathway loci and highlight the need for further detailed characterisation of cannabinoid inheritance to facilitate metabolic engineering of chemically elite germplasm.
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http://dx.doi.org/10.1038/s41598-019-47812-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6684623PMC
August 2019

Developmental Plasticity of the Major Alkyl Cannabinoid Chemotypes in a Diverse Genetic Resource Collection.

Front Plant Sci 2018 23;9:1510. Epub 2018 Oct 23.

Southern Cross Plant Science, Southern Cross University, Lismore, NSW, Australia.

is a chemically diverse domesticated plant genus which produces a unique class of biologically active secondary metabolites referred to as cannabinoids. The affinity and selectivity of cannabinoids to targets of the human endocannabinoid system depend on alkyl side chain length, and these structural-activity relationships can be utilized for the development of novel therapeutics. Accurate early screening of germplasm has the potential to accelerate selection of chemical phenotypes (chemotypes) for pharmacological exploitation. However, limited attempts have been made to characterize the plasticity of alkyl cannabinoid composition in different plant tissues and throughout development. A chemotypic diversity panel comprised of 99 individuals from 20 populations sourced from the Ecofibre Global Germplasm Collection (ecofibre.com.au and anandahemp.com) was used to examine alkyl cannabinoid variation across vegetative, flowering and maturation stages. A wide range of di-/tri-cyclic as well as C-/C-alkyl cannabinoid composition was observed between plants. Chemotype at the vegetative and flowering stages was found to be predictive of chemotype at maturation, indicating a low level of plasticity in cannabinoid composition. Chemometric cluster analysis based on composition data from all three developmental stages categorized alkyl cannabinoid chemotypes into three classes. Our results suggest that more extensive chemical and genetic characterization of the genepool could facilitate the metabolic engineering of alkyl cannabinoid chemotypes.
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http://dx.doi.org/10.3389/fpls.2018.01510DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6206272PMC
October 2018

Association analysis of resistance to cereal cyst nematodes () and root lesion nematodes ( and ) in CIMMYT advanced spring wheat lines for semi-arid conditions.

Breed Sci 2016 Dec 25;66(5):692-702. Epub 2016 Oct 25.

Grains Research & Development Corporation (GRDC) , 4/4 National Circuit Barton 2600 ACT , Australia.

To identify loci linked to nematode resistance genes, a total of 126 of CIMMYT advanced spring wheat lines adapted to semi-arid conditions were screened for resistance to , , and , of which 107 lines were genotyped with 1,310 DArT. Association of DArT markers with nematode response was analyzed using the general linear model. Results showed that 11 markers were associated with resistance to (pathotype Ha21), 25 markers with resistance to , and 9 significant markers were identified to be linked with resistance to . In this work we confirmed that chromosome 4A (~90-105 cM) can be a source of resistance to as has been recently reported. Other significant markers were also identified on chromosomal regions where no resistant genes have been reported for both nematodes species. These novel QTL were mapped to chromosomes 5A, 6A, and 7A for ; on chromosomes 1A, 1B, 3A, 3B, 6B, 7AS, and 7D for ; and on chromosomes 1D, 2A, and 5B for and represent potentially new loci linked to resistance that may be useful for selecting parents and deploying resistance into elite germplasm adapted to regions where nematodes are causing problem.
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http://dx.doi.org/10.1270/jsbbs.15158DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5282747PMC
December 2016

Mixed model association mapping for fusarium head blight resistance in tunisian-derived durum wheat populations.

G3 (Bethesda) 2011 Aug 1;1(3):209-18. Epub 2011 Aug 1.

Sources of resistance to Fusarium head blight (FHB) in wheat are mostly restricted to Chinese hexaploid genotypes. The effort to incorporate the resistance from hexaploid wheat or wild relatives to cultivated durum wheat (Triticum turgidum L. var. durum Desf.) have not been successful in providing resistance to the level of the donor parents. In this study, we used 171 BC(1)F(6) and 169 BC(1)F(7) lines derived from crossing of four Tunisian tetraploid sources of resistance (Tun7, Tun18, Tun34, Tun36) with durum cultivars 'Ben,' 'Maier,' 'Lebsock,' and 'Mountrail' for association studies. The Tun18 and Tun7 FHB resistances were found to be comparable to the best hexaploid wheat sources. A new significant QTL for FHB resistance was identified on the long arm of chromosome 5B (Qfhs.ndsu-5BL) with both association and classical QTL mapping analysis. Linkage disequilibrium (LD) blocks extending up to 40 cM were evident in these populations. The linear mixed model considering the structure (Q or P) and the kinship matrix (K(T)) estimated by restricted maximum likelihood (REML) was identified as the best for association studies in a mixture of wheat populations from a breeding program. The results of association mapping analysis also demonstrated a region on the short arm of chromosome 3B as potentially linked to FHB resistance. This region is in proximity of major FHB resistance gene fhb1 reported in hexaploid wheat. A possibility of having susceptibility or suppressor of resistance gene(s) on durum wheat chromosome 2A was further confirmed in this material, explaining the problem in developing resistant genotypes without counter selection against this region.
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http://dx.doi.org/10.1534/g3.111.000489DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3276138PMC
August 2011