Project description:The main objective of the present study was to identify citrus transcrition factors putatively involved in the juvenile to adult transition in citrus. A oligonucleotide microarray containing 1152 putative unigenes of citrus transcription factors was used. Rough lemon (C. jambirhi Lush.), were analyzed in two diferent developmental stages, junenile and adult. Four replicates for each sample category were generated and for each genotipe juvenile versus adult samples were compared . Comparative transcriptomic hybridization
Project description:Identification of transcription factors potentially involved in the juvenile to adult phase transition in Pineapple sweet orange (C. sinensis (L.)
Project description:The goals of this study are to reveal the transcriptional and regulatory dynamics of the lncRNAs in response to CLas infection and provide a reference for a better understanding of the role of lncRNAs involved in citrus HLB regulation. For the purpose, we obtained RNA-seq-based differential expression profile of the leave midrib of CLas- and mock-inoculated rough lemon and sweet orange at week 0, 7, 17, and 34 following infections with three biological replicates in the greenhouse. Approximately 2,523 million paired-end reads from 48 sample libraries were produced using Illumina HiSeq 2000. we systematically identified lncRNAs from rough lemon and sweet orange at four different time points of a greenhouse experiment and characterized their genomic transcriptional and regulatory dynamics. We predicted their potential regulatory genes and functions and constructed a co-expression network. Our study provides precious information and expands the knowledge of citrus lncRNA against HLB disease.
Project description:Mal secco is one of the most severe diseases of citrus, caused by the necrotrophic fungus Plenodomus tracheiphilus that is widespread in different Mediterranean countries. With the main aim of identifying candidate genes involved in the response of citrus plants to “Mal secco”, we performed a de novo transcriptome analysis of rough lemon seedlings subjected to artificial inoculation of P. tracheiphilus in comparison with plants inoculated with water. The analysis of Differential Expressed Genes (DEGs) highlighted a sharp response triggered by the pathogen as a total of 4,986 significant DEGs (2,865 genes up-regulated and 2,121 down-regulated) have been revealed. The analysis of the most significantly enriched KEGG pathways indicated that a crucial role in the plant response to the fungus is played by genes involved in “Plant hormone signal transduction”, “Phenylpropanoid biosynthesis” and “Carbon metabolism”. The main findings of this work are that under fungus challenge, the rough lemon genes involved both in the light harvesting and the photosynthetic electron flow were significantly down-regulated, thus probably inducing a shortage of energy for cellular functions. Moreover, the systemic acquired resistance (SAR) was activated through the induced salicylic acid cascade. Interestingly, RPM1 interacting protein 4, an essential positive regulator of plant defense, and BIR2, which is a negative regulator of basal level of immunity, have been identified thus representing useful targets for molecular breeding.
Project description:Background: A long juvenile period between germination and flowering is a common characteristic among fruit trees, including Malus hupehensis (Pamp.) Rehd., which is an apple rootstock widely used in China. microRNAs (miRNAs) play an important role in the regulation of phase transition and reproductive growth processes. Results: M. hupehensis RNA libraries, one adult and one juvenile phase, were constructed using tree leaves and underwent high-throughput sequencing. We identified 42 known miRNA families and 172 novel miRNAs. We also identified 127 targets for 25 known miRNA families and 168 targets for 35 unique novel miRNAs using degradome sequencing. The identified miRNA targets were categorized into 58 biological processes, and the 123 targets of known miRNAs were associated with phase transition processes. The KEGG analysis revealed that these targets were involved in starch and sucrose metabolism, and plant hormone signal transduction. Expression profiling of miRNAs and their targets indicated multiple regulatory functions in the phase transition. The higher expression level of mdm-miR156 and lower expression level of mdm-miR172 in the juvenile phase leaves implied that these two small miRNAs regulated the phase transition. mdm-miR160 and miRNA393, which regulate genes involved in auxin signal transduction, could also be involved in controlling this process. The identification of known and novel miRNAs and their targets provides new information on this regulatory process in M. hupehensis, which will contribute to the understanding of miRNA functions during growth, phase transition and reproduction in woody fruit trees. Conclusions: A comprehensive study on M. hupehensis miRNAs related to the juvenile to adult phase transition was performed. The combination of sRNA and degradome sequencing can be used to better illustrate the profiling of hormone-regulated miRNAs and miRNA targets involving complex regulatory networks, which will contribute to the understanding of miRNA functions during growth, phase transition and reproductive growth in perennial woody fruit trees.
Project description:The main objective of the present study was to identify citrus transcrition factors putatively involved in the juvenile to adult transition in citrus. A oligonucleotide microarray containing 1152 putative unigenes of citrus transcription factors was used. Pineapple sweet orange (C. sinensis (L.) was analyzed in two diferent developmental stages, junenile and adult. Four replicates for each sample category were generated and for each genotipe juvenile versus adult samples were compared . Comparative transcriptomic hybridization
Project description:In plants, juvenile to adult phase transition is regulated by the sequential activity of two microRNAs: miR156 and miR172. A decline in miR156 and increase in miR172 abundance is associated with phase transition. There is very limited information on phase transition in economically important horticultural tree crops, which have a significantly long vegetative phase affecting fruit bearing. Here we profiled various molecular cues known to be involved in phase transition and flowering, including the microRNAs miR156 and miR172, in three horticultural tree crops avocado (Persea americana), mango (Mangifera indica) and macadamia (Macadamia integrifolia). We observed that miR156 expression decreases as these trees age and can potentially be used as a juvenility marker. Consistent with findings in annual plants, we also observed conserved regulation of the miR156-SPL3/4/5 regulatory module in these genetically distant tree crops, suggesting that this pathway may play a highly conserved role in vegetative identity. Meanwhile, the abundance of miR172 and its target AP2-like genes, as well as the accumulation level of SPL9 transcripts, were not related with plant age in these crops except in avocado where miR172 expression increased steadily. Finally, we demonstrate that various floral genes, including AP1 and SOC1 were upregulated in the reproductive phase and can be used as potential markers for the reproductive phase transition. Overall, this study provides an insight into the molecular associations of juvenility and phase transition in horticultural trees where crop breeding and improvement is encumbered by long juvenile phases.
Project description:The main objective of the present study was to identify citrus transcrition factors putatively involved in the juvenile to adult transition in citrus. A oligonucleotide microarray containing 1152 putative unigenes of citrus transcription factors was used.
Project description:The main objective of the present study was to identify citrus transcrition factors putatively involved in the juvenile to adult transition in citrus. A oligonucleotide microarray containing 1152 putative unigenes of citrus transcription factors was used.
Project description:Vegetative phase change is the developmental transition from the juvenile phase to the adult phase during which a plant becomes competent for sexual reproduction. Gain of ability to flower is often accompanied by changes in patterns of differentiation in newly forming vegetative organs. In maize, juvenile leaves differ from adult leaves in morphology, anatomy, and cell wall composition. Whereas the normal sequence of juvenile followed by adult is repeated with every sexual generation, this sequence can be altered in maize by the isolation and culture of the shoot apex from an adult phase plant; an “adult” meristem so treated reverts to forming juvenile vegetative organs. To investigate the molecular differences between the juvenile and adult phases in maize comparisons among two juvenile samples, leaf 4 and culture-derived leaf 3 or 4, and an adult sample (leaf 9) were made using cDNA microarrays. All samples were leaf primordia at plastochron 6. A gene was scored as “phase specific” if it was up- (or down-) regulated in both juvenile samples compared to the adult sample with at least a twofold-change in gene expression at P-value less than or equal to 0.005. Some 221 ESTs up-regulated in juvenile and 28 ESTs up-regulated in adult were identified. Altered patterns of expression of selected ESTs in the phase change mutants Tp2, d1 and gl15 further confirmed these genes as being phase-specific and allowed us to position these genes in the known genetic hierarchy regulating phase change. Keywords: Transcript profiling among seed-derived juvenile leaf 4 and adult leaf 9 and culture-rejuvenated leaf 3 or 4 in maize