Project description:Petunia is an excellent model system, especially for genetic, physiological and molecular studies. Thus far, however, genome-wide expression analysis has been rarely applied because of the lack of sequence information. We applied next-generation sequencing to generate, through de novo read assembly, a large catalogue of transcripts for Petunia axillaris and Petunia inflata. On the basis of the transcriptome of each species, comprehensive microarray chips for gene expression analysis were established and used for the analysis of global- and organ-specific gene expression in both species. In addition, microarray analysis was applied to explore the molecular basis of the seed coat defects in Petunia hybrida mutants, homozygous for a null allele of the AN11 gene, encoding a WDR transcription regulator. Among the transcripts differentially expressed in an11 seeds compared to wild type, many expected targets of AN11 were found but also several interesting new candidates that might play a role in morphogenesis of the seed coat. Our results validate the combination of next-generation sequencing with microarray analyses strategies to identify the transcriptome of two petunia species without previous knowledge of their genome, and to develop comprehensive chips as useful tools for the analysis of gene expression in P. axillaris, P. inflata and P. hybrida.
Project description:Petunia is an excellent model system, especially for genetic, physiological and molecular studies. Thus far, however, genome-wide expression analysis has been rarely applied because of the lack of sequence information. We applied next-generation sequencing to generate, through de novo read assembly, a large catalogue of transcripts for Petunia axillaris and Petunia inflata. On the basis of the transcriptome of each species, comprehensive microarray chips for gene expression analysis were established and used for the analysis of global- and organ-specific gene expression in both species. In addition, microarray analysis was applied to explore the molecular basis of the seed coat defects in Petunia hybrida mutants, homozygous for a null allele of the AN11 gene, encoding a WDR transcription regulator. Among the transcripts differentially expressed in an11 seeds compared to wild type, many expected targets of AN11 were found but also several interesting new candidates that might play a role in morphogenesis of the seed coat. Our results validate the combination of next-generation sequencing with microarray analyses strategies to identify the transcriptome of two petunia species without previous knowledge of their genome, and to develop comprehensive chips as useful tools for the analysis of gene expression in P. axillaris, P. inflata and P. hybrida. The manuscript describes the creation by next generation sequencing of a large catalogue of the transcriptome of the two Petunia species, that are considered to represent the natural material from which the breeders selected their varieties. This submission represents the transcriptome component of study. The high throughput sequencing data were submitted to SRA (accession numbers: SRA027293, SRP004866.1, SRX036999.2, SRX036998.2).
Project description:Investigation of gene expression level changes in Petunia hybrida seedlings subjected to cold at 2°C for 0.5 h, 2 h, 24 h and 5 d, compared to the CK.
Project description:Deoxyhypusine synthase (DHS) is encoded by a nuclear gene and is the key enzyme involved in the post-translational activation of the eukaryotic translation initiation factor eIF5A. DHS plays important roles in plant growth and development. To gain a better understanding of DHS, the petunia (Petunia hybrida) PhDHS gene was isolated, and the role of PhDHS in plant growth was analysed. PhDHS protein was localized to the nucleus and cytoplasm. Virus-mediated PhDHS silencing caused a sectored chlorotic leaf phenotype. The chlorophyll levels was reducted and the development of chloroplasts was abnormal in PhDHS-silenced leaves These features were not observed in DHS-suppressed Arabidopsis thaliana and Solanum lycopersicum. These results indicated that PhDHS is required for development in petunia. A proteome assay showed that 308 proteins are up-regulated and 266 proteins are down-regulated in PhDHS-silenced plants compared with control. Among them, 20 proteins in photosystem I and photosystem II and 11 thylakoid proteins were down-regulated in PhDHS-silenced leaves, further supporting the involvement of PhDHS in photosynthesis in petunia.
Project description:N1-methyladenosine is a unique base methylation because it blocks Watson-Crick base paring and introduces a positive charge. Previous studies showed that m1A is prevalent in yeast and mammals mRNA and has a functional role in promoting translation of methylated mRNA. However, little is known about its abundance, topology and dynamics in plant mRNA. In this study, dot blotting and LC–MS/MS analyses reveal a dynamic pattern of m1A mRNA modification in various tissues and at different developmental stages in petunia (Petunia hybrida). Transcriptome-wide profiling of mRNA m1A in petunia was reported by applying m1A mRNA immunoprecipitation followed by a deep-sequencing approach (m1A-seq). m1A-seq analysis identified 4993 m1A peaks in 3231 expressed genes in petunia corollas. Each methylated gene averagely carries 1.55 peaks. Among the identified m1A peaks, there are 251 m1A peaks in which the adenines was partly replaced by thymine (T) and/or the reverse transcription stops happened in adenine site, in 199 expressed genes. We found that m1A is enriched in coding sequences with one peaks located immediately after start codons, and a slight negative correlation between methylated genes and gene expression was observed. Totally, ethylene treatment reduced the m1A level of mRNA in petunia corollas. We show that a RNA m1A-methyltransferase, tRNA specific methyltransferase 61A (PhTRMT61A), is an m1A mRNA methyltransferase. PhTRMT61A silencing results in decreased m1A peaks in mRNA in leaves and abnormal leaf development. PhTRMT61A is located to the nucleus. Our results suggest that m1A in mRNA is an important epitranscriptome marker and plays a role in plant development.