Project description:Plants have the ability to shed organs that are no longer in use. In Arabidopsis thaliana abscission of floral organs involves cell wall remodeling and cell expansion prior to cell wall dissolution. IDA encodes a secreted peptide that signals through the leucine-rich repeat receptor-like kinases (LRR-RLKs) HAESA (HAE) (At4g28490) and HASEA-LIKE2 (HSL2) (At5g65710). Arabidopsis thaliana (ecotype Colombia-0) plants were kept in growth chambers with a 16/8 h (light/dark) photoperiod at 22 M-BM-0C, and 100 mE m-2 s-1 light intensity. 4 biological replicates were prepared from each sample, each containing abscission zone regions of siliques position 4 to 8 (when counting from the flowe at anthesis at the top of the inflorescence) from plants with at least 20 siliques. Differences in transcriptional responses were measured by comparing genes expression in abscission zones of ida-2 plants (SALK_133209) against abscission zones from control plants.
Project description:Plants have the ability to shed organs that are no longer in use. In Arabidopsis thaliana abscission of floral organs involves cell wall remodeling and cell expansion prior to cell wall dissolution. IDA encodes a secreted peptide that signals through the leucine-rich repeat receptor-like kinases (LRR-RLKs) HAESA (HAE) (At4g28490) and HASEA-LIKE2 (HSL2) (At5g65710). Arabidopsis thaliana (ecotype Colombia-0) plants were kept in growth chambers with a 16/8 h (light/dark) photoperiod at 22 M-BM-0C, and 100 mE m-2 s-1 light intensity. 4 biological replicates were prepared from each sample, each containing abscission zone regions of siliques position 4 to 8 (when counting from the flowe at anthesis at the top of the inflorescence) from plants with at least 20 siliques. Differences in transcriptional responses were measured by comparing genes expression in abscission zones of hae hsl2 plants (SALK_021905 x SALK_030520) against abscission zones from control plants.
Project description:The receptor-like protein kinases encoded by HAESA (HAE) and HAESA-LIKE 2 (HSL2) are essential for floral organ abscission in Arabidopsis thaliana and the double hae hsl2 mutant fails to abscise. Expression of HAE and HSL2 is specific to Abscission Zone (AZ) cells and is higher in stage 15 flowers than in earlier developmental stages. By stage 16 floral organs have begun to abscise, suggesting that HAE HSL2 are most active in stage 15 flowers. Samples were enriched for AZ RNA by isolating RNA from flower receptacles, the region from the base of the flower to slightly above the base of attachment of the sepals, petals, and stamen. RNA-seq was then used to analyze and compare the transcriptomes of wild type and hae-3 hsl2-3 mutants. 2034 genes were differentially expressed with a False Discovery Rate adjusted p < 0.05, of which 349 genes 2 fold or greater change. Of these 349, 277 were lower in the mutant and 72 were higher. Differentially expressed genes with lower expression were enriched for hydrolytic enzymes, cell-wall modifying enzymes, and defense related genes. This suggests that HAE HSL2 signaling regulates gene expression of enzymes necessary for abscission.
Project description:Versatile roles of REVOLUTA (REV), a Class III homeodomain-leucine zipper (HD-ZIP III) transcription factor, have been mainly depicted in Arabidopsis and Populus. In this study, we investigated the functions of its tomato homolog, namely SlREV. Over-expression of a microRNA166-resistant version of SlREV (35S::REVRis) not only resulted in vegetative abnormities such as curly leaves and fasciated stems, but also caused dramatic reproductive alterations including continuous production of flowers at pedicel abscission zone (AZ) and ectopic fruit formation on receptacles. Microscopic analysis showed that meristem-like structures continuously emerged out from the exodermises of pedicel AZs and ectopic carpels formed between the first and the second whorl of floral buds in 35S::REVRis plants. Therefore, we performed Illumina’s digital gene expression (DGE) system, a tag-based transcriptome sequencing methodTranscriptional data to dicover differential expressed genes in early buds (1-2 mm floral buds at stage 6-8) of overexpression line SlREVRis-1. The result suggests that SlREV may regulate genes related to meristem maintenance and cell differentiation in the development of flower pedicel abscission zone, and modulate genes in homodomain and MADS-box families and hormone pathways during fruit formation. These results reveal important roles of SlREV in tomato. 1-2 mm floral buds at stage 6-8 were sampled from three individual plants of 35S::REVRis-1 and corresponding WT control. Three aliquots of RNA from transgenic or WT plants were pooled. Then, the digital expression profile were generated by Illumina Cluster Station and Illumina HiSeq™ 2000 System (BGI Inc.).
Project description:Versatile roles of REVOLUTA (REV), a Class III homeodomain-leucine zipper (HD-ZIP III) transcription factor, have been mainly depicted in Arabidopsis and Populus. In this study, we investigated the functions of its tomato homolog, namely SlREV. Over-expression of a microRNA166-resistant version of SlREV (35S::REVRis) not only resulted in vegetative abnormities such as curly leaves and fasciated stems, but also caused dramatic reproductive alterations including continuous production of flowers at pedicel abscission zone (AZ) and ectopic fruit formation on receptacles. Microscopic analysis showed that meristem-like structures continuously emerged out from the exodermises of pedicel AZs and ectopic carpels formed between the first and the second whorl of floral buds in 35S::REVRis plants. Therefore, we performed Illumina’s digital gene expression (DGE) system, a tag-based transcriptome sequencing methodTranscriptional data to dicover differential expressed genes in early buds (1-2 mm floral buds at stage 6-8) of overexpression line SlREVRis-1. The result suggests that SlREV may regulate genes related to meristem maintenance and cell differentiation in the development of flower pedicel abscission zone, and modulate genes in homodomain and MADS-box families and hormone pathways during fruit formation. These results reveal important roles of SlREV in tomato.
Project description:The receptor-like protein kinases encoded by HAESA (HAE) and HAESA-LIKE 2 (HSL2) are essential for floral organ abscission in Arabidopsis thaliana and the double hae hsl2 mutant fails to abscise. Expression of HAE and HSL2 is specific to Abscission Zone (AZ) cells and is higher in stage 15 flowers than in earlier developmental stages. By stage 16 floral organs have begun to abscise, suggesting that HAE HSL2 are most active in stage 15 flowers. Samples were enriched for AZ RNA by isolating RNA from flower receptacles, the region from the base of the flower to slightly above the base of attachment of the sepals, petals, and stamen. RNA-seq was then used to analyze and compare the transcriptomes of wild type and hae-3 hsl2-3 mutants. 2034 genes were differentially expressed with a False Discovery Rate adjusted p < 0.05, of which 349 genes 2 fold or greater change. Of these 349, 277 were lower in the mutant and 72 were higher. Differentially expressed genes with lower expression were enriched for hydrolytic enzymes, cell-wall modifying enzymes, and defense related genes. This suggests that HAE HSL2 signaling regulates gene expression of enzymes necessary for abscission. 6 samples were sequenced, 3 biological replicates of Col-0 wild type and 3 biological replicates of the hae-3 hsl2-3 double mutant. Samples were barcoded and all 6 samples multiplexed and sequenced on 3 lanes, each lane on a separate flow cell, of an Illumina HiSeq 2000.
Project description:Abscission is a cell separation process that takes place in particular positions of the plant body named abscission zones. In citrus, maturing fruits are shed through the calix abscission zone, which is composed by 10-15 cell layers located at the boundary between the calyx button and the fruit rind. In order to gain further insight into the molecular mechanisms involved in citrus fruit abscission, we used laser microdissection combined with microarray analysis to compare the global expression profiles of calyx abscission zone cells and adjacent fruit rind cells (control cells) at 0, 12 and 24 hours after the activation of the process with ethylene. Thus, this study allowed identifying a set of abscission zone-specifically expressed genes potentially involved in citrus fruit abscission.
Project description:Plants have the ability to shed organs that are no longer in use. In Arabidopsis thaliana abscission of floral organs involves cell wall remodeling and cell expansion prior to cell wall dissolution. IDA encodes a secreted peptide that signals through the leucine-rich repeat receptor-like kinases (LRR-RLKs) HAESA (HAE) (At4g28490) and HASEA-LIKE2 (HSL2) (At5g65710).