Project description:Honokiol (HNK), one of the main medicinal components in Magnolia officinalis, possesses antimicrobial activity against a variety of pathogenic bacteria and fungi.S. cerevisiae is a model eukaryote used for investigating the cellular and molecular mechanisms of anti-fungal drugs. To explore the molecular mechanism of its anti-fungal activity, we determined the effects of HNK on the mRNA expression profile of Saccharomyces cerevisiae using a DNA microarray approach.
Project description:Cornus officinalis Sieb. et Zucc., a perennial woody plant which is recognized with high medicinal, economic and ecological values, has been used as traditional Chinese medicine (TCM) for thousands of years in China. Modern pharmacological research has revealed that cornel iridoid glycosides (CIGs, e.g. loganin and morroniside) in dried pericarp of C. officinalis have significant medicinal activities for strengthening immune functions. However, little is known on the molecular processes responsible for the medical properties of this species, owing to the absence of genomic resources such as available sequences of key enzyme genes in biosynthetic pathways. In this study, the RNA sequencing data of C. officinalis were first generated and used for transcriptome analysis. A total of 54,827 unigenes with an average length of 817 bp, an N50 of 1,379 bp, and an average GC content of 44.91% were yielded by de novo assembly, of which 31,780 unigenes were successfully annotated. As potential molecular markers, 121, 118, 96, 89, and 82 transcription factors belonged to bHLH, MYB, PHD, WRKY, and AP2-ERF were further analyzed, respectively. The results of qRT-PCR confirmed that geraniol 10-hydroxylase (G10H) and loganin synthase (SLS) were differentially expressed in fruits and leaves during different growing stages. Furthermore, we found that loganin accumulation was positively related to G10H expression but was negatively correlated with SLS expression. Collectively, the genomic information and gene expression results presented in this study will be helpful for future studies on gene discovery and molecular process of loganin synthesis in C. officinalis.
Project description:Primary cell wall is an essential cell structure for plant playing major roles in plant growth, differentiation, and stress responses. Here we demonstrate that a group of AP2-ERF transcription factor regulates primary cell wall formation and can induce massive accumulation of it in empty fiber cell of the nst1-1 nst3-1 mutant lacking secondary cell wall in Arabidopsis. The transgenic plants expressing one of the AP2-ERF transcription factors fused with VP16 transcriptional activation domain under the control of NST3 promoter in the nst1-1 nst3-1 mutant showed similar level of cell wall contents with wild type by the massive accumulation of cell wall which lacks lignin and xylan. The transgenic plants showed 70% higher saccharification efficiency than wild type. Gene expression analysis using microarray revealed that genes related to primary cell wall were highly upregulated in the transgenic plant. Moreover, chimeric-activator of the AP2-ERF transcription factor accelerated cell wall regeneration of mesophyll protoplast of Arabidopsis while the chimeric-repressor retarded it. These data suggest that the group of AP2-ERF transcription factor is key regulator of the primary cell wall formation in plant and could be employed to produce massive cell wall with readily extractable feature.
Project description:In this study, the genes that encode AP2/ERF transcription factors, namely OpERF1 to OpERF5, were isolated from HR of O. pumila. Phylogenetic analysis of AP2/ERF protein sequences suggested the close evolutionary relationship of OpERF1 with stress-responsive ERF factors in Arabidopsis and of OpERF2 with ERF factors reported to regulate alkaloid production, such as ORCA3 in Catharanthus roseus, NIC2-locus ERFs in tobacco, and JRE4 in tomato. We generated the HR lines of O. pumila, ERF1i and ERF2i, in which the expression of OpERF1 and OpERF2, respectively, was suppressed using RNA interference technique. The transcriptome and metabolome of these suppressed HR were analyzed for functional characterization of OpERF1 and OpERF2.
