Comparative transcriptome profiling unveils the role of differentially charged gold nanoparticle in growth, metabolic regulation and defence response of micro-propagated Nardostachys jatamansi Wall. ex DC.
Shubham Joshi, Rohit Joshi, Rohit Joshi
Abstract
Nardostachys jatamansi is a Himalayan medicinal plant known for its excellent antioxidant and metabolic properties. Differentially charged gold nanoparticles were reported earlier to play immense role in improvement of organogenesis and cellular homeostasis in different plant species. In this study, efforts were made to unveil the molecular programming underpinning the elicitation response of charged gold nanoparticles in N. jatamansi under in vitro conditions. RNA sequencing of in vitro developed shoots subjected to control, 60 µM citrate-AuNPs and 40 µM CTAB-AuNPs, generated 217.1 million sequenced reads that identified 104, 1255 and 660 significantly differentially expressed genes in non-treated control vs 60 µM citrate-AuNPs, non-treated control vs 40 µM CTAB-AuNPs and 60 µM citrate-AuNPs vs 40 µM CTAB-AuNPs libraries, respectively. Gene ontology (GO) analysis revealed that major biological, cellular and metabolic processes were affected more by CTAB-AuNP treatment than by citrate-AuNP treatment. Several DEGs were identified having key role in growth, antioxidant potential, hormonal regulation, metabolite production, and stress response. KEGG analysis revealed differentially expressed genes associated with photosynthesis, antioxidant activity, hormone metabolism, cellular internalisation, secondary metabolites biosynthesis and defence response. Transcription factors regulating these pathways such as Myb, WRKY, NAC, ERF, bHLH and dof were reported to be upregulated. In conclusion, positively charged CATB-AuNPs were found to be more effective than negatively charged Citrate-AuNPs for in vitro propagation. Thus, besides providing insights into molecular dynamics underlying in vitro nono-elicitation affecting proliferation of N. jatamansi , our study also provides ample genomic resources for the in vitro improvement of medicinal plants.