Biology subjects

Monthony, A. S.

Publications and source records attributed to Monthony, A. S..

9 recordsLinked to original sources

bioRxiv2026

A pistillate-biased epidermal regulatory program underlies glandular trichome development in Cannabis sativa

Glandular trichomes are specialized epidermal structures on Cannabis sativa L. inflorescences that synthesize and store cannabinoids and terpenoids, making them central to the species economic and medicinal value. Although trichome development is a multistage genetic process, its regulatory basis in C. sativa remains poorly understood, particularly with respect to sexual dimorphism and sex plasticity. Here, we combined orthologybased gene discovery with transcriptomic profiling to investigate trichome development across four floral phenotypes: female flowers (FF), male flowers (MF), induced male flowers on XX plants (IMF), and induced female flowers on XY plants (IFF). Using trichome development-related genes from Arabidopsis thaliana, a model for unicellular non-glandular trichome development, and Solanum lycopersicum, a model for multicellular glandular trichomes, we identified and mapped 53 candidate C. sativa trichome development regulator genes (CsTDRGs). The CsTDRG set did not support a simple Arabidopsis- or tomato-like model, but instead included Arabidopsis-like epidermal fate components, including MBW-related regulators and GL2, alongside tomato-like multicellular trichome regulators, including MIXTA-like, HD-ZIP IV, WOX, MTR, GRAS, and hormone-associated candidates. RNA-seq analysis showed that CsTDRG expression was more strongly associated with floral phenotype than chromosomal sex. Genes with preferential expression in pistillate tissues were CsTT8, CsMYC1/GL3, CsGL2, CsYABBY4 and CsMIXTA-like1/MYB106, whereas CsMTR1, CsGRAS9, and CsCKX3 were upregulated in male (MF and IMF) flower. These findings suggest that sexually dimorphic trichome development in C. sativa reflects differential regulation of a shared developmental toolkit that combines conserved epidermal fate components with multicellular and glandular trichome regulatory modules.

developmental biology↗

bioRxiv2026

Ethylene-Gibberellin Crosstalk Drives Phenotypic Sex Changes in Cannabis sativa

Abstract/SummarySex expression in Cannabis sativa is determined by XX/XY sex chromosomes but remains plastic, with ethylene inhibition inducing male flowers on XX plants and ethylene release inducing female flowers on XY plants. Although ethylene is a central regulator of this process, the contribution of gibberellin signaling to cannabis sex reversal remains poorly defined. Here, we reconstructed the GA biosynthesis, regulation, and signaling pathway in C. sativa and profiled GA-related gene expression during chemically induced sex reversal. Orthology-based searches identified 50 putative C. sativa GA-related genes, widely distributed across the genome, with the X chromosome harboring 11 genes, including six within the non-recombining region. Transcriptomic analyses across vegetative baseline, early post-treatment leaves, and developing flowers showed that expression profiles were broadly similar between XX and XY plants at day 0, weakly perturbed at day 1, and strongly structured by floral phenotype at day 14. Early responses were limited to downregulation of CsGA3ox1 in ethephon-treated XY plants and CsGASA1 in STS-treated XX plants. By day 14, sex reversal was associated with differential expression of key genes, including CsGA1, multiple GA20ox orthologs, CsGID1B, CsSLY2, and several GASA genes, indicating broad remodeling of GA regulation. Our findings position the GA pathway as a downstream module of ethylene-driven sex reversal in C. sativa, with GA activity tracking floral sexual identity, extending the framework of sexual plasticity beyond ethylene, and identifying candidate genes for functional validation and the development of sex-stable cultivars.

developmental biology↗

bioRxiv2025

Sex-Specific Ethylene Responses and Convergent Plasticity: Multi-Omic Insights into Cannabis Sexual Plasticity

Cannabis sativa L. exhibits remarkable sexual plasticity: both XX and XY individuals can undergo complete phenotypic sex reversal in response to ethylene modulation. While this phenomenon is well documented, the molecular mechanisms remain underexplored. Here, we present the first multi-omic study of hormonally induced sex change in both XX and XY Cannabis plants, integrating transcriptomic profiling, ethylene pathway metabolite quantification, and whole-genome sequencing across three genetically distinct genotypes. Treatments with silver thiosulfate (STS) and ethephon induced >80% phenotypic conversion, but transcriptomic responses diverged sharply between chromosomal sexes. We profiled 47 ethylene-related genes (ERGs) and identified 14 high-confidence candidates--including CsACS1, CsACO5, CsERF1, and CsMTN--with sex-specific, time-dependent expression patterns that support a two-phase model of plasticity: early transcriptional reprogramming followed by stabilization of new floral identities. Several candidate ERGs were in non-recombining regions of the X chromosome or absent from the Y, while most showed low nucleotide diversity, suggesting functional constraint. These findings provide a high-resolution view of ethylene-responsive sex plasticity and demonstrate that convergent floral phenotypes arise from distinct regulatory programs in XX and XY plants. Our work advances the molecular understanding of sexual plasticity in dioecious species and identifies candidate genes for the development of sex-stable cultivars in Cannabis and other crops.

developmental biology↗

bioRxiv2025

DESeq2-MultiBatch: Batch Correction for Multi-Factorial RNA-seq Experiments

RNA sequencing (RNA-seq) experiments frequently encounter batch effects that can significantly distort biological interpretations, particularly in complex, multifactorial studies where biological variables interact with experimental batch conditions. Existing batch correction tools primarily address technical variability and often neglect these critical interaction effects, resulting in incomplete adjustments. To address this gap, we introduce DESeq2-MultiBatch, a novel, lightweight batch correction method implemented entirely within the DESeq2 analytical framework. Unlike conventional approaches, DESeq2-MultiBatch directly leverages DESeq2s internal model estimates to correct raw gene count data, accurately adjusting for experimental batch effects, including interactions with biological variables. Here, we demonstrate that DESeq2-MultiBatch effectively mitigates batch-related variability while preserving genuine biological differences. Benchmarking against widely used methods highlights DESeq2-MultiBatch as a robust, practical solution for improving exploratory data visualization and downstream analyses in multifactorial RNA-seq studies. Availability and implementationhttps://github.com/julienroyulaval/DESeq2-MultiBatch Contactjulien.roy.10@ulaval.ca Supplementary informationSupplementary data are available at Bioinformatics online.

bioinformatics↗

bioRxiv2024

A Comparison of the Sexual Expression, Biomass, Cannabinoid Content, and Seed Production in XXX and XXY Triploid Cannabis

Cannabis is a multi-billion dollar industry reliant on unpollinated genetically female (XX) plants, as pollination reduces cannabinoid yields and flower quality. The mechanism behind the sexual expression of C. sativa is unclear. This study examines the sexual characteristics of homo- and hetero-gametic triploid cannabis plants (XX(X/Y)) to understand the role of the Y chromosome in cannabis sex determination. Heterogametic triploids were produced by crossing a male diploid C. sativa cv. Durban Poison (2n = 2x = 18 + XY) with a tetraploid female C. sativa cv. Higher Education (2n = 4x = 36 + XXXX) confirmed by flow cytometry and PCR. Measurements include fresh and dry plant weight, dry flower weight, seed counts, seed weights, and cannabinoids quantified using liquid chromatography. Results showed 44.4% of plants were XXY (n = 8), with 75% presenting a monoecious phenotype (n = 6). Of these, 50% produced predominately male flowers (n = 3), while the rest produced predominately female flowers. Plants with predominately female flowers had higher yields and cannabinoids compared to predominantly male plants. XXX genotypes outperformed XXY in several metrics. This study enhances our understanding of C. sativa sex determination and offers insight into breeding and cultivation strategies utilizing triploid cannabis.

plant biology↗

bioRxiv2024

Ethylene sensitivity assay for medicinal and fiber-type Cannabis seedlings reveals a triple-response-like phenotype

As evidence mounts for ethylenes important role in sex determination, understanding ethylene signaling in Cannabis sativa L. (cannabis) has become increasingly vital. This study investigated the response of hemp-type and drug-type Cannabis sativa seedlings to ethylene, revealing a unique paired response phenotype under dark conditions and ethephon treatment, suggesting a more specialized variation of the triple response distinct from that observed in other species. Employing a novel ethephon-based assay, this research bypassed the complexities of using gaseous ethylene, providing a more accessible method for examining ethylene responses. The results showed C. sativa seedlings exhibit marked sensitivity to ethephon at concentrations (125 mg/L, 250 mg/L, and 500 mg/L) lower than those previously reported to influence mature plants, indicating a broad ethylene responsiveness across various genetic backgrounds. Furthermore, the reversal of ethylene-induced phenotypic changes by silver thiosulfate (STS) at all concentrations tested (1, 2, and 3 mM) suggests the conservation of ethylene signaling pathways in C. sativa. Importantly these phenotypic responses were observed in both drug and hemp type cannabis. However, the absence of an exaggerated apical hook in treated seedlings potentially points to a unique regulatory mechanism in response to ethylene in achene-bearing plants. These findings, highlighted by the successful induction of ethylene-sensitive phenotypes, underscore the conserved nature of ethylene signaling in C. sativa. The results highlight the need for further investigations into the regulatory mechanisms of ethylene in cannabis, especially concerning sexual development, opening new pathways for optimized breeding and cultivation practices aimed at enhancing plant growth and reproductive strategies.

plant biology↗

bioRxiv2023

Exploring Ethylene-Related Genes in Cannabis sativa: Implications for Sexual Plasticity

Sexual plasticity is a phenomenon wherein organisms possess the ability to alter their phenotypic sex in response to environmental and physiological stimuli, without modifying their sex chromosomes. Cannabis sativa L., a medically valuable plant species, exhibits sexual plasticity when subjected to specific chemicals that influence ethylene biosynthesis and signaling. Nevertheless, the precise contribution of ethylene-related genes (ERGs) to sexual plasticity in cannabis remains unexplored. The current study employed Arabidopsis thaliana L. as a model organism to conduct gene orthology analysis and reconstruct the Yang Cycle, ethylene biosynthesis, and ethylene signaling pathways in C. sativa. Additionally, two transcriptomic datasets comprising male, female, and chemically induced male flowers were examined to identify expression patterns in ERGs associated with sexual determination and sexual plasticity. These ERGs involved in sexual plasticity were categorized into two distinct expression patterns: floral organ concordant (FOC) and unique (uERG). Furthermore, a third expression pattern, termed karyotype concordant (KC) expression, was proposed, which plays a role in sex determination. The study revealed that CsERGs associated with sexual plasticity are dispersed throughout the genome and are not limited to the sex chromosomes, indicating a widespread regulation of sexual plasticity in C. sativa. Key MessagePresented here are model Yang cycle, ethylene biosynthesis and signaling pathways in Cannabis sativa. C. sativa floral transcriptomes were used to predict putative ethylene-related genes involved in sexual plasticity in the species.

plant biology↗

bioRxiv2020

Flower Power: Floral reversion as a viable alternative to nodal micropropagation in Cannabis sativa.

The legalization of Cannabis sativa L. for recreational and medical purposes has been gaining global momentum, leading to a rise in interest in Cannabis tissue culture as growers look for large-scale solutions to germplasm storage and clean plant propagation. Mother plants used in commercial propagation are susceptible to insect pests and disease and require considerable space. While micropropagation can produce disease free starting material in less space, current published in vitro micropropagation methods are not robust and few report high multiplication rates. Further, these micropropagation methods rely on photoperiod-sensitive plants which can be maintained in a perpetual vegetative state. Current methods are not adaptable to long-term tissue culture of day-neutral cultivars, which cannot be maintained in perpetual vegetative growth. In this study, we chose to develop a micropropagation system which uses C. sativa inflorescences as starting materials. This study used two cannabis cultivars, two plant growth regulators (PGR; 6-benzylaminopurine and meta-topolin) at different concentrations, and two different numbers of florets. Here we show that floral reversion occurs from meristematic tissue in C. sativa florets and that it can be used to enhance multiplication rates compared to existing in vitro methods. Floret number was shown to have a significant impact on percent reversion, with pairs of florets reverting more frequently and producing healthier explants than single florets, while cultivar and PGR had no significant effect on percent reversion. Compared with our previously published nodal culture studies, the current floral reversion method produced up to eight times more explants per tissue culture cycle. Floral reversion provides a foundation for effective inflorescence-based micropropagation systems in C. sativa.

plant biology↗

bioRxiv2020

Recalcitrance of Cannabis sativa to de novo regeneration; a multi-genotype replication study

Cannabis sativa is relatively recalcitrant to regeneration from somatic tissues, but several reports have been published demonstrating a response. Most reports show low levels of regeneration from somatic tissues, but a landmark publication by Lata et al. in 2010 reported regeneration from leaf explants with a 96% response rate, producing an average of 12.3 shoots per explant in a single, high-THC genotype. Despite the importance regeneration plays in plant biotechnology this protocol has not been used in subsequent papers in the decade since it was published, raising the concern that it is not reproducible. Many researchers are looking to build research programmes in this growing field, and it is important that the reproducibility and robustness of single-genotype C. sativa regeneration protocols undergo multi-lab validations to ensure they are reproducible across the species. Replication studies in this burgeoning field will help research groups avoid lost time and resources which arise from pursuing protocols that are not reproducible. Here we test the replicability of this protocol across 10 drug-type C. sativa genotypes. This protocol successfully induced callus in all 10 genotypes. Callus size and appearance substantially differed among cultivars, with the most responsive genotype producing 6-fold more callus than the least responsive genotype. However, the most successful shoot induction medium developed in the 2010 paper failed to induce regeneration in any of the cultivars tested, resulting in the eventual necrosis of the calli. Based on this replication study, it is evident that the existing regeneration protocol is not robust and could not be replicated in any of the 10 genotypes tested.View Full Text

plant biology↗