ABSTRACT: Integrated transcriptomic and metabolomics analysis reveal the molecular mechanism of flower color differentiation of Orychophragmus violaceus
Project description:Petal is not only the target of selection by horticulturalists to enhance the ornamental value of plants but also emerged as a unique model system for plant organogenesis studies. It is known that three major groups of pigments, betalains, carotenoids and anthocyanins, are responsible for the attractive natural display of flower colors. While carotenoids and betalains generally yield yellow or red colors, anthocyanins confer a diverse range of color from orange to red to violet and blue. In this study, we collected 11 species (Erysimum cheiri, Malcolmia maritime, Brassica oleracea, Raphanus sativus, Orychophragmus violaceus, Eruca sativa, Orychophragmus violaceus, Iberis amara, Aubrieta x cultorum, Lobularia maritime, Matthiola incana) belong to different tribe in Brassicaceae family with varied flower color and performed petal transcriptome analysis. de novo transcriptome assembly showed that average length of the contigs varied from 631bp in O. violaceus to 1212bp in Matthiola incana which indicated that the complexity of the genomes are different much. Protein homology between these species and those sequenced species in Brassicaceae family are consistent with the known phylogenetic relationships. However, O. violaceus has closer relationships with Sisymbrium irio than expected Brassica species. Clustering analysis of genes in anthocyanin and carotenoids synthesis pathway indicated that while silence or low expression of CCD4 (Carotenoid Cleavage Dioxygenase 4) leading to the yellow color formation in different species, purple or red color variation might result from different genes expression variation. These results not only provide transcriptome data for petal development study but also provide useful information for Brassica flower improvement for ornamental purpose.
Project description:Oilseed rape is both an important oleaginous crop and agriculture sightseeing crop whereas has relatively scanty flower color. As natural flavonoids, Anthocyanin are responsible for the attractive red, purple, and blue colors of various tissues in higher plants, especially for the ornamental plants flower. One Brassica napus-Orychophragmus violaceus disomic addition line (M4) obtained previously exhibits red petals whichresult from anthocyanin biosynthesis. Transcriptome analysis of M4, B. napus (H3), natural individuals of O. violaceus with purple petals (OvP) and white petals (OvW) revealed that most of structural genes for the anthocyanin synthesis were up-regulated in both M4 and OvP, especially key gene ANS in the last step. Reads assembling and sequence alignment showed that the regulatory DEG PAP2 in M4 was from the transcript of O. violaceus. OvPAP2 was transformed into Arabidopsis thaliana and B. napus driven by the CaMV35S promoter and the rape petal-specific prompter XY355. Transgenic A. thaliana plants showed different levels of purple pigments in most of the organs, including the petals, and transgenic B. napus flowers exhibited restricted accumulation of anthocyanins in stamens when driven by CaMV35S promoter, but generated both red petals and anthers driven by the XY355 promoter. These results provided a platform for expounding the anthocyanin biosynthesis pathway in B. napus petals and give a successful case for flower color modification of the agriculture sightseeing rape.
Project description:Marigold (Tagetes erecta L.) is an important ornamental plant with a wide variety of colors. Despite its economic value, there are few biochemical and molecular basic studies of flower color in marigold. To study the mechanism behind its color formation, metabolomics analysis and de novo cDNA sequencing was performed on marigold inbred line ‘V-01’ and its petal color mutant ‘V-01M’, in four flower developmental stages.