Project description:We identified PRP4 kinase-A (PRP4ka) in a forward genetic screen based on an alternatively-spliced GFP reporter gene in Arabidopsis thaliana (Arabidopsis). Prp4 kinase, which was the first spliceosome-associated kinase shown to regulate splicing in fungi and mammals, has not yet been studied in plants. Analysis of RNA-seq data from the prp4ka mutant revealed widespread perturbations in alternative splicing. A quantitative iTRAQ-based phosphoproteomics investigation of the mutant identified phosphorylation changes in several serine/arginine-rich proteins, which regulate constitutive and alternative splicing, as well as other splicing-related factors. The results demonstrate the importance of PRP4ka in alternative splicing and suggest that PRP4ka may influence alternative splicing patterns by phosphorylating a subset of splicing regulators.
Project description:Several pathways conferring environmental flowering responses in Arabidopsis converge on developmental processes that mediate floral transition in the shoot apical meristem. Many characterized mutations disrupt these environmental responses, but downstream developmental processes have been more refractory to mutagenesis. We constructed a quintuple mutant impaired in several environmental pathways and showed that it possesses severely reduced flowering responses to changes in photoperiod and ambient temperature. RNA-seq analysis of the quintuple mutant showed that the expression of genes encoding gibberellin biosynthesis enzymes and transcription factors involved in the age pathway correlates with flowering. Mutagenesis of the quintuple mutant generated two late-flowering mutants, quintuple ems 1 (qem1) and qem2. The mutated genes were identified by isogenic mapping and transgenic complementation. The qem1 mutant was an allele of ga20ox2, confirming the importance of gibberellin for flowering in the absence of environmental responses. By contrast, the qem2 mutation is in CHROMATIN REMODELING 4 (CHR4), which has not been genetically implicated in floral induction. Using co-immunoprecipitation, RNA-seq and ChIP-seq, we show that CHR4 interacts with transcription factors involved in floral meristem identity and affects expression of key floral regulators. We conclude that CHR4 mediates the response to endogenous flowering pathways in the inflorescence meristem to promote floral identity.
Project description:In this project, we profiled the dynamics of proteome during Arabidopsis early embryogenesis using nanoproteomics. In addition, we identified some proteins which may be important during this process. Combining with RNA-seq, we unveiled the relationship between RNA and proteins during Arabidopsis early embryogenesis.
Project description:An updated representation of S. meliloti metabolism that was manually-curated and encompasses information from 240 literature sources, which includes transposon-sequencing (Tn-seq) data and Phenotype MicroArray data for wild-type and mutant strains.
