Project description:De novo shoot regeneration is an essential step for massive propagation and genetic engineering of elite germplasm in forestry. Poplar that is a fast growth tree species have a very important ecologically and economically role around the world, especially in China. In this study, we found that PtWOX11 that is a homologue of AtWOX11 not only involved de novo root formation but also promote de novo shoot regeneration in poplar. We demonstrated that PtWOX11 can enhance callus regeneration competence and shoot regeneration during two-step de novo shoot regeneration. Furthermore, by using RNA-seq and qPCR, we uncovered that during callus induction stage PtWOX11 activates PtPLTs expression to promote callus formation and regeneration competence, and promote PtCUC2/3, PtWUSa and PtSTM transcription to fulfil shoot organogenesis during shoot regeneration stage. Overall, our data indicated that PtWOX11 play a new function and transcriptional regulation mechanism on de novo shoot regeneration in poplar.
Project description:Effect of the presence of fruits on the expression of genes possibly involved in floral induction in the terminal meristem of spur bourse shoot. Investigation on mecanisms involved in Biennial Bearing in mature apple trees cultivar Royal Gala.
Project description:Protein arginine methylation plays essential roles in diverse biological processes, but its role in regulating shoot regeneration remains elusive. In this study, we analyzed the function of the protein arginine methyltransferase AtPRMT5 during de novo shoot regeneration in Arabidopsis. AtPRMT5 encodes a type II PRMT that methylates proteins, including histones and RNA splicing factors. Mutation of AtPMRT5 decreased the frequency of shoot regeneration and number of shoots per callus in the atprmt5 mutant compared with those of the wild type. To understand the mechanism of AtPRMT5 regulation of shoot regeneration, we analyzed the transcript levels of wild type and the mutant atprmt5 calli during shoot regeneration by RNA-seq. Three biological repeats of wild type and the mutant atprmt5-1 calli were used for RNA sequencing. Total RNAs were isolated from the calli of wild type Col and the mutant atprmt5-1 cultured on cultured on shoot-induction medium. The RNA-seq llibraries were constructed with TruSeq Stranded mRNA Library Prep Kit and sequenced using the Illumina Hiseq 2500. The raw reads were aligned to the genome sequences of TAIR10 using Tophat software. The gene expression levels were measured in RPKM, and many critical genes regulated by AtPRMT5 were identified to be involved in shoot regeneration.
Project description:48 apple trees from a segregating F1 population from a cross of 'Ottawa 3' x 'Robusta 5' were analyzed by microarray to identify gene expression differences between the individuals to correlate gene expression patterns with phenotypic traits segregating in the population 48 individual apple trees were assayed once each using RNA isolated from a single shoot tip from each tree. There were no biological or technical replicates in the experiment. There was no control sample, since all 48 were compared to each other.
Project description:The capacity of plant regeneration in different ecotypes of Arabidopsis largely varies. However, the mechanism underlying this process remains exclusive. Here, we identified a critical thioredoxin gene DCC1 in determining natural variation for shoot regeneration in Arabidopsis. Functional loss of DCC1 resulted in the repression of shoot regeneration. DCC1 encodes a thioredoxin, which was localized in mitochondria. DCC1 directly interacted with CARBONIC ANHYDRASE 2 (CA2) to regulate the mitochondrial respiratory complex activity and mediate the Reactive Oxygen Species (ROS) level. Defects of DCC1 or CA2 caused the increased ROS level. To understand the regulatory mechanism of DCC1-mediated ROS in shoot regeneration, we analyzed the transcript levels of wild type Col-0 and the mutant dcc1 calli during shoot regeneration by RNA-seq. Three biological repeats of wild type Co-0 and the mutant dcc1 calli were used for RNA sequencing. Total RNAs were isolated from the calli of wild type Col-0 and the mutant dcc1 cultured on shoot-induction medium. The RNA-seq was performed using the Illumina Hiseq 2500. The raw reads were aligned to the genome sequences of TAIR10 using Tophat2 software. The gene expression levels were measured in FPKM, and many critical genes were identified to be involved in shoot regeneration.
Project description:miRNAs are key players in multiple biological processes, therefore analysis and characterization of these small regulatory RNAs is a critical step towards better understanding of animal and plant biology. In apple (Malus domestica) two hundred microRNAs are known, which most probably represents only a fraction of miRNAome diversity. As a result, more effort is required to better annotate miRNAs and their functions in this economically important species. We performed deep sequencing of twelve small RNA libraries obtained for fire blight resistant and fire blight sensitive trees. In the sequencing results we identified 116 novel microRNAs and confirmed a majority of previously reported apple miRNAs. We then experimentally verified selected candidates with RT-PCR and stem-loop qPCR and performed differential expression analysis. Finally, we identified and characterized putative targets of all known apple miRNAs. In this study we considerably expand the apple miRNAome by identifying and characterizing dozens of novel microRNAs. Moreover, our data suggests that apple microRNAs might be considered as regulators and markers of fire blight resistance. Actively-growing shoot tip tissue samples were collected from twelve apple trees, which includes three biological replicates of each following scion-rootstock combinations: B.9, G.30, M.111 and M.27.
Project description:Plants can regenerate from a variety of tissues on culturing in appropriate media. However, the metabolic shifts involved in callus formation and shoot regeneration are largely unknown. The metabolic profiles of callus generated from tomato (Solanum lycopersicum) cotyledons and that of shoot regenerated from callus were compared with the pct1-2 mutant that exhibits enhanced polar auxin transport and the shr mutant that exhibits elevated nitric oxide levels. The transformation from cotyledon to callus involved a major shift in metabolite profiles with denser metabolic networks in the callus. In contrast, the transformation from callus to shoot involved minor changes in the networks. The metabolic networks in pct1-2 and shr mutants were distinct from wild type and were rewired with shifts in endogenous hormones and metabolite interactions. The callus formation was accompanied by a reduction in the levels of metabolites involved in cell wall lignification and cellular immunity. On the contrary, the levels of monoamines were upregulated in the callus and regenerated shoot. The callus formation and shoot regeneration were accompanied by an increase in salicylic acid in wild type and mutants. The transformation to the callus and also to the shoot downregulated LST8 and upregulated TOR transcript levels indicating a putative linkage between metabolic shift and TOR signalling pathway. The network analysis indicates that shift in metabolite profiles during callus formation and shoot regeneration is governed by a complex interaction between metabolites and endogenous hormones.
Project description:Plants generally possess a strong ability to regenerate organs; for example, in tissue culture, shoots can regenerate from callus, a clump of actively proliferating, undifferentiated cells. Processing of pre-mRNA and ribosomal RNAs is important for callus formation and shoot regeneration. However, our knowledge of the roles of RNA quality control via the nonsense-mediated mRNA decay (NMD) pathway in shoot regeneration is limited. Here, we examined the shoot regeneration phenotypes of the low-beta-amylase1 (lba1)/upstream frame shift1-1 (upf1-1) and upf3-1 mutants, in which the core NMD components UPF1 and UPF3 are defective. These mutants formed callus from hypocotyl explants normally, but this callus behaved abnormally during shoot regeneration: the mutant callus generated numerous adventitious root structures instead of adventitious shoots in an auxin-dependent manner. Quantitative RT-PCR and microarray analyses showed that the upf mutations had widespread effects during culture on shoot-induction medium. In particular, the expression patterns of early auxin response genes, including those encoding AUXIN/INDOLE ACETIC ACID (AUX/IAA) family members, were significantly affected in the upf mutants. Also, the upregulation of shoot apical meristem-related transcription factor genes, such as CUP-SHAPED COTYLEDON1 (CUC1) and CUC2, was inhibited in the mutants. Taken together, these results indicate that NMD-mediated transcriptomic regulation modulates the auxin response in plants and thus plays crucial roles in the early stages of shoot regeneration.
Project description:Effect of the presence of fruits on the expression of genes possibly involved in floral induction in the terminal meristem of spur bourse shoot. Investigation on mecanisms involved in Biennial Bearing in mature apple trees cultivar Royal Gala. Two-condition experiment : 'ON' trees (unthinned control) & 'OFF' trees (deflowered) for comparison. Three comparisons at sampling dates : 28, 48 and 119 days after full bloom (DAFB). Two dye switch biological replicates for each treatment and sampling date.