Project description:Wood is one of the most important and enormous biomass that is widely used in our life. It is formed by successive addition of secondary xylem that develops continuously from cambium. The transcriptome of nst1 nst3 âdouble-knockoutâ lines was examined to know the effect of mutations on wood formation. Experiment Overall Design: Total RNA was extracted from the base 4 cm part of inflorescence stems whose heights were between 12 and 17 cm of three independent nst1-1 nst3-1 double T-DNA tagged lines and the whole transcriptome was compared with that of wild-type plant.
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:Wood is one of the most important and enormous biomass that is widely used in our life. It is formed by successive addition of secondary xylem that develops continuously from cambium. The transcriptome of nst1 nst3 “double-knockout” lines was examined to know the effect of mutations on wood formation. Keywords: mutant vs wt comparison
Project description:The Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), acts as a key regulator of xylem vessel differentiation. In order to identify direct target genes of VND7, we performed global transcriptome analysis using Arabidopsis transgenic lines in which VND7 activity could be induced post-translationally. This analysis identified 63 putative direct target genes of VND7, which encode a broad range of proteins, such as transcription factors, IRREGULAR XYLEM proteins and proteolytic enzymes, known to be closely associated with xylem vessel formation. Recombinant VND7 protein binds to several promoter sequences present in candidate direct target genes: specifically, in the promoter of XYLEM CYSTEINE PEPTIDASE1, two distinct regions were demonstrated to be responsible for VND7 binding. We also found that expression of VND7 restores secondary cell wall formation in the fiber cells of inflorescence stems of nst1 nst3 double mutants, as well as expression of NAC SECONDARY WALL THICKENING PROMOTING FACTOR3 (NST3, however, the vessel-type secondary wall deposition was observed only as a result of VND7 expression. These findings indicated that VND7 upregulates, directly and/or indirectly, many genes involved in a wide range of processes in xylem vessel differentiation, and that its target genes are partially different from those of NSTs.
Project description:As sessile organisms, plants require dynamic pathways in order to recognize pathogens and coordinate plant defenses by signalling. Agrobacterium tumefaciens C58 is able to avoid triggering plant defenses prior to entering the cell, and therefore is only detected once infection has begun making Agrobacterium a plant pathogen to numerous plant species. Understanding plant responses to Agrobacterium will be useful in improving plant defenses and potentially may also improve plant transformation efficiency. Microarrays were utilized for detailing the global gene expression pattern in A. thaliana Col-0 roots in response to A. tumefaciens C58 for the identification of differentially expressed genes.