Project description:The plant vascular system is essential for the enlarged plant stature and successful colonizzation the land by delivering resources throughout the plants and providing mechanical support. Despite several regulators of vascular patterning have been reported, how vascular system mediates stress resistance remain largely unknown. Here we identified a CsIND transcription factor that is specifically expressed in the xylem and phloem tissues in cucumber. Knock down of CsIND by RNAi lead to dwarf plants with enlarged or disorganized vascular systems in all aerial organs. The content of both auxin and jasmonic acid were increased in the CsIND-RNAi lines. Transcriptome profiling by RNA-Seq hints CsIND-regulated gene networks for defense response and vascular development. Biochemical analyses verified that CsIND directly binds to well-known vascular regulators including CsCCR1, CsMYB116, CsYAB5, CsBP and CsAUX, and physically interacts with dorsiventral patterning genes CsKAN2 and CsYAB5. Further, CsIND-RNAi plants displayed significantly enhanced tolerance to nitrogen dificency and resistance to cucumber downy mildew. Therefore, CsIND regulates vascular formation and resistance to biotic and abiotic stresses in cucumber, through the combinarory interactions with well-known vascular regulaors and hormone metabolism and signaling pathways.
Project description:Cucumber (Cucumis sativus L.) is an economically important vegetable cultivated all over the world. Grafting can produce bloomless or sparse-bloom cucumber, which is welcomed by increasing consumers. Bloom granule is tine glandular hair, which is hard and rare studied on its formation and related genes. Mutifunctional RNA-seq is a recently developed analytical approach for transcriptome profiling via high-throughput sequencing and has been recently applied to a wide variety of organisms, which provide us reliable technical means detect bloom formation and related genes. In this study, we chose a cucumber inbred line (Shannong No.5) and two pumpkin rootstock lines as materials, and constructed four tested cucumbers, grew plants in “Yamazaki cucumber nutrient solution formula” prepared by deionized water, treated plants with or without 1.7mM potassium silicate 2 hours before collecting pericarp. Each treatment were duplicated twice.16 cDNA libraries were constructed from pericarp of a cucumber inbred line (own-rooted cucumber), C/C (self-grafted cucumber), M/C (More bloom, cucumber grafted onto “3225” rootstock) and L/C(Less bloom, cucumber grafted onto “3212” rootstock). We obtained 17,215,769~17,529,047 high quality reads, and 18,804~19,358 genes from each sample. All reads can be mapped to the cucumber genome (Version 2). By RPKM comparing, we got 38 comparing combinations with differentially expressed genes (DEGs), obtained 38 significantly expressed combinations by FDR≤0.001 and the absolute value of log2Ratio≥1 as the thresholds. These results suggest that there are many differences and genes expression mode among effects of grafting or added silicon. This study addresses a preliminary analysis and offers a foundation for future genomic research in the bloom formation of cucumber.
Project description:Plant roots possess a remarkable regenerative potential owing to the presence of stem cells that constantly generate new tissues. Key molecular mechanisms have been linked to this potential, among which the ETHYLENE RESPONSE FACTOR 115 (ERF115) that plays a predominant role in the activation of regenerative cell divisions. However, the downstream operating molecular machinery driving wound-activated cell divisions is largely unknown. Here, we biochemically and genetically identified the GRAS-domain transcription factor protein SCARECROW-LIKE 5 (SCL5) as an interaction partner of ERF115. Although being non-essential under control growth conditions, SCL5 drives redundantly with the related PAT1 and SCL21 transcription factors the expression of the DNA-BINDING ONE FINGER 3.4 (DOF3;4) transcription factor gene. DOF3.4 expression is wound inducible and ERF115 dependent, and in turn activates D3-type cyclin expression. Accordingly, ectopic DOF3.4 expression drives periclinal cell division, whereas its downstream D3-type cyclins are essential for regeneration. The data highlight the importance of the PAT1-branch of GRAS-domain transcription factors for wound activated regeneration processes and pinpoint the DOF3.4 transcription factor as a key element driving regenerative cell divisions.
