Project description:Trichomes are the hair-like structures that are widely present on the surface of aerial organs and function in plant defense against biotic and abiotic stresses. Previous studies focus on the single cell trichomes in Arabidopsis and cotton, or multicellular glandular trichomes in tomato, but the developmental process and molecular mechanisms controlling multicellular non-glandular trichome development are largely neglected. Here, we extensively characterized the fruit trichome (spine) development in wild type cucumber and in a tiny branched hair (tbh) mutant that contains a spontaneous mutation and has hairless foliage and smooth fruit surface. Our data indicated that cucumber trichome was multicellular and non-glandular, with no branches or endoreduplication. Further, the major feature of cucumber trichome development was spine base expansion. Transcriptome profiling through Digital Gene Expression indicated that meristem-related genes and transcription factors were implicated in the fruit spine development, and polarity regulators were upregulated during spine base expansion. qRT-PCR verified the reliability of our RNA-SEQ data, and in situ hybridization confirmed the enriched expression of meristem regulators CUP-SHAPED COTYLEDON3 (CUC3) and STM (SHOOT MERISTEMLESS) , as well as the abaxial identity gene KANADI (KAN) in cucumber fruit spine. Together, our results suggest a distinct regulatory pathway involving meristem genes and polarity regulators in multicellular trichome development in cucumber. Using Digital Gene Expression technology to compare the genome-wide gene expression profiles in the fruit spines of wild type cucumber and the tbh mutant, as well as the fruit spines on fruits of 0.5cm and 1.6cm long, repectively. Two biological repelicates were generated for each tissue.
Project description:Trichomes are the hair-like structures that are widely present on the surface of aerial organs and function in plant defense against biotic and abiotic stresses. Previous studies focus on the single cell trichomes in Arabidopsis and cotton, or multicellular glandular trichomes in tomato, but the developmental process and molecular mechanisms controlling multicellular non-glandular trichome development are largely neglected. Here, we extensively characterized the fruit trichome (spine) development in wild type cucumber and in a tiny branched hair (tbh) mutant that contains a spontaneous mutation and has hairless foliage and smooth fruit surface. Our data indicated that cucumber trichome was multicellular and non-glandular, with no branches or endoreduplication. Further, the major feature of cucumber trichome development was spine base expansion. Transcriptome profiling through Digital Gene Expression indicated that meristem-related genes and transcription factors were implicated in the fruit spine development, and polarity regulators were upregulated during spine base expansion. qRT-PCR verified the reliability of our RNA-SEQ data, and in situ hybridization confirmed the enriched expression of meristem regulators CUP-SHAPED COTYLEDON3 (CUC3) and STM (SHOOT MERISTEMLESS) , as well as the abaxial identity gene KANADI (KAN) in cucumber fruit spine. Together, our results suggest a distinct regulatory pathway involving meristem genes and polarity regulators in multicellular trichome development in cucumber.
Project description:Trichomes are found on the leaf surface of many plant species. They can be classified into either glandular or non-glandular types. Glandular trichomes are usually multicelluar structures and have long been known to participate in defense against pathogens through the production of specialized chemical products. Non-glandular trichomes, such as those in Arabidopsis thaliana, have been hypothesized to have roles in physical defense against insects, UV protection, detoxification, and heat dispersal. However, it has been difficult to separate a physical role from other possible functions for non-glandular trichomes. We have taken advantage of several mutants in the trichome developmental pathway and gene expression analyses to identify a set of genes expressed predominantly in Arabidopsis trichomes. Keywords: comparing gene expression between wild type and mutants
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:Previous study we have reported the cucumber TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) family gene BRANCHED1 (CsBRC1) as a main transcription factor functions to regulate shoot branching. Here, we found CsBRC1 (CsTCP18b in this study) had a paralogous gene CsTCP18a. To investigate whether the function of CsTCP18a was same as CsTCP18b, we carried out biochemical experiments and genetic transformation. The Real-Time PCR and in situ hybridization showed that CsTCP18a displayed different expression patterns in cucumber compared with CsTCP18b. Ectopic expression of CsTCP18a in Arabidopsis tcp18 (brc1) mutants resulted in a decreased number of rosette branches and rosette leaves, whereas silencing CsTCP18a in cucumber only led to a deformed true leaf of seedling without influencing the shoot branching. RNA-seq analysis of wild-type plants and CsTCP18a-RNAi lines implicated that CsTCP18a regulated early leaf development of cucumber through affecting the transcripts of auxin and cytokinin related genes. Further studies indicated that CsTCP18a could directly interact with CsTCP10 and CsTCP18b in vitro and in vivo. Therefore, our data suggested that CsTCP18a had functional redundancy with CsTCP18b in inhibiting axillary buds outgrowth, and it could also regulate leaf development during cucumber seedling.