Transcriptomic and metabolic responses of Calotropis procera to salt and drought stress

Background: Calotropis procera is a wild plant species in the family Apocynaceae that is able to grow in harsh, arid and heat stressed conditions. Understanding how this highly adapted plant persists in harsh environments should inform future efforts to improve the hardiness of crop and forage plant species. To study the plant response to droμght and osmotic stress, we treated plants with polyethylene glycol and NaCl and carried out transcriptomic and metabolomics measurements across a time-course of five days. Results: We identified a highly dynamic transcriptional response across the time-course including dramatic changes in inositol signaling, stress response genes and cytokinins. The resulting metabolome changes also involved sharp increases of myo-inositol, a key signaling molecule and elevated amino acid metabolites at later times. Conclusions: The data generated here provide a first glimpse at the expressed genome of C. procera, a plant that is exceptionally well adapted to arid environments. We demonstrate, through transcriptome and metabolome analysis that myo-inositol signaling is strongly induced in response to drought and salt stress and that there is elevation of amino acid concentrations after prolonged osmotic stress. This work should lay the foundations of future studies in adaptation to arid environments

Transcriptional analysis of Rhazya stricta in response to jasmonic acid

Background: Jasmonic acid (JA) is a signal transducer molecule that plays an important role in plant development and stress response; it can also efficiently stimulate secondary metabolism in plant cells. Results: RNA-Seq technology was applied to identify differentially expressed genes and study the time course of gene expression in Rhazya stricta in response to JA. Of more than 288 million total reads, approximately 27% were mapped to genes in the reference genome. Genes involved during the secondary metabolite pathways were up- or downregulated when treated with JA in R. stricta. Functional annotation and pathway analysis of all up- and downregulated genes identified many biological processes and molecular functions. Jasmonic acid biosynthetic, cell wall organization, and chlorophyll metabolic processes were upregulated at days 2, 6, and 12, respectively. Similarly, the molecular functions of calcium-transporting ATPase activity, ADP binding, and protein kinase activity were also upregulated at days 2, 6, and 12, respectively. Time-dependent transcriptional gene expression analysis showed that JA can induce signaling in the phenylpropanoid and aromatic acid pathways. These pathways are responsible for the production of secondary metabolites, which are essential for the development and environmental defense mechanism of R. stricta during stress conditions. Conclusions: Our results suggested that genes involved in flavonoid biosynthesis and aromatic acid synthesis pathways were upregulated during JA stress. However, monoterpenoid indole alkaloid (MIA) was unaffected by JA treatment. Hence, we can postulate that JA plays an important role in R. stricta during plant development and environmental stress conditions. How to cite: Hajrah, NH, Rabah SO, Alghamdi MK, et al. Transcriptional analysis of Rhazya stricta in response to jasmonic acid. Electron J Biotechnol 2021;50. https://doi.org/10.1016/j.ejbt.2021.01.00

Gene expression profiling to elucidate the pharmacological and toxicological effects of Ricinus communis L. leaf extract in mammalian cells

Ricinus communis is a traditional medicinal plant which has been utilized for centuries for treatment of various conditions. Due to the presence of diverse phytochemicals, Ricinus is an outstanding natural resource to discover new drugs for various diseases such as diabetes, cancer, arthritis, ulcer and asthma. In this study, we performed whole-genome gene expression profiling using RNA-Seq to determine the differentially expressed genes in a mammalian cell line after exposure to Ricinus leaf extract and elucidate their pharmacological effects in order to support its ethnomedicinal uses. Various genes involved in cancer, inflammation, atherosclerosis and diabetes were found to be differentially regulated after exposure to sub-lethal concentrations of the Ricinus extract in MCF7 cells. An important gene involved in cancer progression and metastasis, that is, PIK3R3 (Phosphatidylinositol 3-kinase regulatory subunit gamma), was downregulated in MCF7 cells after treatment with Ricinus extract. PIK3R3 is an important component of the PI3K/AKT signalling pathway which is essential for cell proliferation, angiogenesis, inhibition of apoptosis and metastasis to distant organs. The Ricinus extract downregulated the expression of DPP4 (Dipeptidyl peptidase-4) and upregulated the expression of PPAR-γ (Peroxisome proliferator-activated receptor gamma) which are crucial in controlling blood glucose levels. Expression of TNFAIP6 (Tumor necrosis factor-inducible gene 6), which is shown to mediate anti-inflammatory and protective effects, was increased after treatment with Ricinus extract. We also analyzed the genes which might also confer toxicity. Our gene expression profiling data corroborate the potential therapeutic benefits of Ricinus communis plant

L'Auto-vélo : automobilisme, cyclisme, athlétisme, yachting, aérostation, escrime, hippisme / dir. Henri Desgranges

17 juillet 19171917/07/17 (A18,N6021)