Project description:Lateral organ development is important for cucumber yield, while the molecular mechanism controlling leaf and floral organ development in cucumber remain elusive. In this report, a novel EMS-mutaginized mutant, round leaf (rl) was distinguished with remarkable round leaf shape, abnormal floral organ and inhibited tendril outgrowth in early development phase. Moreover, the ovule organogenesis disrupted completely in parthenocarpy fruit of rl. MutMap+ analysis revealed that RL encodes a protein kinase PINOID (CsPID, Csa1G537400). A non-synoymous SNP in the second exon of CsPID resulted in an amino-acid substitution from Arg in the wild type to Lys in the rl mutant. CsPID was down-regulated in rl mutant and preferentially expressed in young leaf, and flower buds. IAA quantification showed that rl plants exhibited a lower IAA content than wild type in ovary and blade edge. IAA immunolocalization results confirmed the IAA content alteration in rl plants. Transcriptome profile analysis further suggested IAA biosynthesis, polar transport and signal transduction genes participated in the leaf and floral development process by CsPID. Biochemical analyses showed that CsPID may regulate leaf shape by interacting with CsREV. In conclusion, this study revealed that the extensive genetic architecture of lateral organ organogenesis and development via CsPID regulating auxin polar transport action in cucumber.
Project description:We compared organ specific chloroplast gene expression in cucumber between fully developed leaves (12th counting from the bottom of plant) and growing tips, female flowers, young leaves, young fruits (3-5 cm long). We have also characterized chloroplast gene transcription in cucumber etiolated seedlings in comparison to mature cucumber leaves.
Project description:N6-methyladenosine (m6A) in mRNA is key to eukaryotic gene regulation. Many m6A functions involve RNA-binding proteins that recognize m6A via a YT521-B Homology (YTH) domain. YTH domain proteins contain long intrinsically disordered regions (IDRs) that may mediate phase separation and interaction with protein partners, but whose precise biochemical functions remain largely unknown. The Arabidopsis thaliana YTH domain proteins ECT2, ECT3 and ECT4 accelerate organogenesis through stimulation of cell division in organ primordia. Here, we use ECT2 to reveal molecular underpinnings of this function. We show that stimulation of leaf formation requires the long N-terminal IDR, and we identify two short IDR-elements required for ECT2-mediated organogenesis. Of these two, a 19-amino acid region containing a tyrosine-rich motif conserved in both plant and metazoan YTHDF proteins is necessary for binding to the major cytoplasmic poly(A)-binding proteins PAB2, PAB4 and PAB8. Remarkably, overexpression of PAB4 in leaf primordia partially rescues the delayed leaf formation in ect2 ect3 ect4 mutants, suggesting that the ECT2-PAB2/4/8 interaction on target mRNAs of organogenesis-related genes may overcome limiting PAB concentrations in primordial cells.
Project description:In order to better understand the commonalities and differences in lateral root and nodule development, we compared their organogenesis and correlated this with changes in gene expression. To initiate lateral roots in Medicago truncatula we turned 2-day-old seedlings 135°, before returning them to their original axis of growth, while for nodule initiation we applied droplets of Sinorhizobium meliloti on the susceptibility zone of the root.
Project description:The anamniote lateral line system, comprising mechanosensory neuromasts and electrosensory ampullary organs, is a useful model for investigating the developmental and evolutionary diversification of different organs and cell types. Zebrafish neuromast development is increasingly well understood, but neither zebrafish nor Xenopus is electroreceptive and our molecular understanding of ampullary organ development is rudimentary. We have used RNA-seq to generate a lateral line-enriched gene-set from late-larval paddlefish (Polyodon spathula). Validation of a subset reveals expression in developing ampullary organs of transcription factor genes critical for hair cell development, and genes essential for glutamate release at hair cell ribbon synapses, suggesting close developmental, physiological and evolutionary links between non-teleost electroreceptors and hair cells. We identify an ampullary organ-specific proneural transcription factor, and candidates for the voltage-sensing L-type Cav channel and rectifying Kv channel predicted from skate (cartilaginous fish) ampullary organ electrophysiology. Overall, our results illuminate ampullary organ development, physiology and evolution.
Project description:We report the comparison of transcriptomic profiles in specific lateral root tissues for Col-0 wild type and puchi-1 mutant seedlings. Lateral root organogenesis is a key process in plant root system development and adaptation to the environment. To dissect the molecular events occurring during the early phase, we generated time-series transcriptomic datasets profiling lateral root development in puchi-1 and wild type backgrounds. Consistent with a mutually inhibitory mechanism, transcriptomic and reporter analysis revealed meristem-related genes were ectopically expressed during early stages of lateral root primordium formation in puchi-1. We conclude that PUCHI participates to the coordination of lateral root patterning and represses ectopic establishment of meristematic cell identities during early stages of organ development.
Project description:The Arabidopsis thaliana transcription factor LATERAL ORGAN BOUNDARIES (LOB) is expressed in the boundary between the shoot apical meristem and initiating lateral organs. To identify genes regulated by LOB activity, we used an inducible 35S:LOB-GR line. This analysis identified genes that are differentially expressed in response to ectopic LOB activity.
Project description:Genome wide transcriptome profiling of pericycle cells from roots exposed to auxin, cytokinin and both hormones simultaneously. Lateral root organogenesis in Arabidopsis is governed by a complex network of hormonal regulations. Plant hormones auxin and cytokinin were demonstrated to be the key regulators of this lateral root organogenesis and their mode of interaction is antagonistic. The aim of the project is to understand the role of the auxin - cytokinin signalling pathways in lateral root organogenesis.
Project description:The Arabidopsis thaliana transcription factor LATERAL ORGAN BOUNDARIES (LOB) is expressed in the boundary between the shoot apical meristem and initiating lateral organs. To identify genes regulated by LOB activity, we used an inducible 35S:LOB-GR line. This analysis identified genes that are differentially expressed in response to ectopic LOB activity. 35S:LOB-GR and Col wild-type seedlings were treated with dexamethasone (DEX) or mock-treated. Three biological replicates were conducted for each treatment.