Virus-induced gene silencing as a tool for functional studies in Cleome violacea

Nectary development in Cleome violacea

Nectaries are a promising frontier for plant evo-devo research, and are particularly fascinating given their diversity in form, position, and secretion methods across angiosperms. Emerging model systems permit investigations of the molecular basis for nectary development and nectar secretion across a range of taxa, which addresses fundamental questions about underlying parallelisms and convergence. Herein, we explore nectary development and nectar secretion in the emerging model taxa, Cleome violacea (Cleomaceae), which exhibits a prominent adaxial nectary. First, we characterized nectary anatomy and quantified nectar secretion to establish a foundation for quantitative and functional gene experiments. Next, we leveraged RNA-seq to establish gene expression profiles of nectaries across three key stages of development: pre-anthesis, anthesis, and post-fertilization. We then performed functional studies on five genes that were putatively involved in nectary and nectar formation: CvCRABSCLAW (CvCRC), CvAGAMOUS (CvAG), CvSHATTERPROOF (CvSHP), CvSWEET9, and a highly expressed but uncharacterized transcript. These experiments revealed a high degree of functional convergence to homologues from other core Eudicots, especially Arabidopsis. CvCRC, redundantly with CvAG and CvSHP, are required for nectary initiation. Concordantly, CvSWEET9 is essential for nectar formation and secretion, which indicates that the process is eccrine based in C. violacea. While demonstration of conservation is informative to our understanding of nectary evolution, questions remain. For example, it is unknown which genes are downstream of the developmental initiators CvCRC, CvAG, and CvSHP, or what role the TCP gene family plays in nectary initiation in this family. Further to this, we have initiated a characterization of associations between nectaries, yeast, and bacteria, but more research is required beyond establishing their presence. Cleome violacea is an excellent model for continued research into nectary development because of its conspicuous nectaries, short generation time, and close taxonomic distance to Arabidopsis.

Theoretical evaluation of Cleome species' bioactive compounds and therapeutic potential: A literature review

The species of Cleome genus are taxonomically included in the family of Cleomaceae and in the order of Brassicales, representing flowering plants with a long history of use in traditional medicine. Phytochemical screening experiments revealed that Cleome species contain a wide range of beneficial bioactive compounds, including alkaloids, essential oils, fatty acids, flavonoids, terpenes, sterols, and anthocyanins, indicating a therapeutic potential. Furthermore, due to the presence of these phytocompounds, there are various plant species in this genus that have demonstrated a wide range of genotypic, chemo typic, and biological activity in several ecological settings around the world. The potential biological actions and pharmacological effects, such as analgesic, anti-inflammatory, antipyretic, anti-diabetic, antidepressant, antibacterial, anti-arthritic, anticancer, and hepatoprotective are closely related to the active substances contained in various parts of the plants. By centralizing medical data provided by the scientific literature, we offer in the present work a comprehensive perspective on a wide range of bioactive compounds identified from diverse Cleome species, emphasizing the correlation of natural active substances with potential pharmacological activities that can contribute to the improvement of therapeutic management for a range of pathologies. In addition, this review suggests future research perspectives to improve the use of phytochemicals contained in the species of Cleome genus, both in terms of increasing therapeutic efficacy and safety profiles, but also in terms of identifying a possible new pharmacological effect.