Project description:Grafting is an ancient cloning method that has been used widely for thousands of years in agricultural practices. However, the molecular mechanisms for graft union development are still largely unknown. The developmental stage of graft union was characterized based on micrografting method. Microarray data revealed a signal exchange process between cells of scion and stock at 1dag, which reestablished the communication network in graft union. This process was concomitant with the cleaning of cell debris, and both of the processes were initiated by a wound-induced program. The results demonstrate the feasibility and potential power of investigating various plant developmental processes by this method and represent a primary and significant step in interpretation of the molecular mechanisms underlying graft union development.
Project description:Grafting is an ancient cloning method that has been used widely for thousands of years in agricultural practices. However, the molecular mechanisms for graft union development are still largely unknown. The developmental stage of graft union was characterized based on micrografting method. Microarray data revealed a signal exchange process between cells of scion and stock at 1dag, which reestablished the communication network in graft union. This process was concomitant with the cleaning of cell debris, and both of the processes were initiated by a wound-induced program. The results demonstrate the feasibility and potential power of investigating various plant developmental processes by this method and represent a primary and significant step in interpretation of the molecular mechanisms underlying graft union development. WT/WT seedling grafts of 22-26 hours after grafting were collected for microarray, intact WT seedlings and ungrafted scions and stocks were as control. All three types of sample, grafts (marked as A: whole graft), ungrafted scions and stocks (marked as B: mixture of ungrafted scions and stocks) and intact seedlings (marked as C: whole seedling), were collected at the same time of 22-26 hours after grafting. For sample B, scions and stocks were cut at the same time during grafting. For sample C, intact seedlings were also reserved during grafting. Data were firstly compared between sample A and C, differential expressed probe sets were than tested based on A and B to obtain graft-specific probes.
Project description:We grafted Transcriptional Gene Silencing (TGS)-inducing wild type Arabidopsis and a mutant that is compromised in 24 nucleotide (nt) small RNA (sRNA) production onto a wild type reporter line. We observed that 21-24 nt sRNAs were transmitted across a graft union yet only the 24 nt sRNAs directed RNA-dependent DNA methylation (RdDM) and TGS of a transgene promoter in meristematic cells.
Project description:We grafted Transcriptional Gene Silencing (TGS)-inducing wild type Arabidopsis and a mutant that is compromised in 24 nucleotide (nt) small RNA (sRNA) production onto a wild type reporter line. We observed that 21-24 nt sRNAs were transmitted across a graft union yet only the 24 nt sRNAs directed RNA-dependent DNA methylation (RdDM) and TGS of a transgene promoter in meristematic cells. Analysis of sRNAs associated with mobile TGS by deep sequencing, biological replicates. 10 unique samples, 5 biological replicates.
Project description:A silencing signal in plants with an RNA specificity determinant moves through plasmodesmata and the phloem. To identify the mobile RNA we grafted Arabidopsis thaliana shoots to roots that would be a recipient for the silencing signal. Using high throughput sequencing as a sensitive detection method and mutants to block small RNA (sRNA) biogenesis in either source or recipient tissue, we detected endogenous and transgene specific sRNA that moved across the graft union. Surprisingly we found that the mobile endogenous sRNAs account for a substantial proportion of the sRNA in roots and we provide evidence that 24nt mobile sRNAs direct epigenetic modifications in the genome of the recipient cells. Mobile sRNA thus represents a mechanism for transmitting the specification of epigenetic modification and could affect genome defence and responses to external stimuli that have persistent effects in plants. Keywords: Small RNA Analysis, Epigenetics