Phylogenetic and expression analysis of SEPALLATA-like gene in Brassica oleracea L. var. acephala / 生物工程学报

The E class MADS-box genes SEPALLATA (SEP)-like play critical roles in angiosperm reproductive growth, especially in floral organ differentiation. To analyze the sequence characteristics and spatio-temporal expression patterns of E-function MADS-box SEP-like genes during kale (Brassica oleracea L. var. acephala) flower development, BroaSEP1/2/3 (GenBank No. KC967957, KC967958, KC967960) homologues, three kale SEP MADS-box gene, were isolated from the kale variety 'Fourteen Line' using Rapid amplification of cDNA ends (RACE). Sequence and phylogenetic analysis indicated that these three SEP genes had a high degree of identity with SEP1, SEP2, SEP3 from Brassica oleracea var. oleracea, Brassica rapa, Raphanus sativus and Brassica napus, respectively. Alignment of the predicted amino acid sequences from these genes, along with previously published subfamily members, demonstrated that these genes comprise four regions of the typical MIKC-type MADS-box proteins: the MADS domain, intervening (I) domain and keratin-like (K) domain, and the C-terminal domain SEPⅠ and SEP Ⅱ motif. The longest open reading frame deduced from the cDNA sequences of BroaSEP1, BroaSEP2, and BroaSEP3 appeared to be 801 bp, 759 bp, 753 bp in length, respectively, which encoded proteins of 266, 252, and 250 amino acids respectively. Expression analyses using semi-quantitative RT-PCR and quantitative real-time PCR indicate that BroaSEP1/2/3 are specifically expressed in floral buds of kale during flower development process. The expression levels of the three genes are very different at different developmental stages, also in wild type, mutant flower with increased petals, and mutant flower with decreased petals. These different patterns of gene expression maybe cause the flowers to increase or decrease the petal number.

Transcriptome analysis of female and male flower buds of Idesia polycarpa Maxim. var. vestita Diels

Background: Idesia polycarpa Maxim. var. vestita Diels, a dioecious plant, is widely used for biodiesel due to the high oil content of its fruits. However, it is hard to distinguish its sex in the seedling stage, which makes breeding and production problematic as only the female tree can produce fruits, and the mechanisms underlying sex determination and differentiation remain unknown due to the lack of available genomic and transcriptomic information. To begin addressing this issue, we performed the transcriptome analysis of its female and male flower. Results: 28,668,977 and 22,227,992 clean reads were obtained from the female and male cDNA libraries, respectively. After quality checks and de novo assembly, a total of 84,213 unigenes with an average length of 1179 bp were generated and 65,972 unigenes (78.34%) could be matched in at least one of the NR, NT, Swiss-Prot, COG, KEGG and GO databases. Functional annotation of the unigenes uncovered diverse biological functions and processes, including reproduction and developmental process, which may play roles in sex determination and differentiation. The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed many unigenes annotated as metabolic pathways, biosynthesis of secondary metabolites pathways, plant­ pathogen interaction, and plant hormone signal transduction. Moreover, 29,953 simple sequence repeats were identified using the microsatellite software. Conclusion: This work provides the first detailed transcriptome analysis of female and male flower of I. polycarpa and lays foundations for future studies on the molecular mechanisms underlying flower bud development of I. polycarpa.

Changes of secondary metabolites and trace elements in gentiana macrophylla flowers: A potential medicinal plant Part / 中草药·英文版

Objective: To search for the potential medicinal plant part of Gentiana macrophylla based on changes of secondary metabolites and trace elements in the flowers of G. macrophylla. Methods: HPLC was used to detect the changes of the active constituents (longanic acid, sweroside, gentiopicroside, and swertiamarin) and ICP-AES was used for mineral nutrients in G. macrophylla during flower development. And soluble sugar, starch, crude protein, hemicelluloses, cellulose, and lignin were determined. Results: Biomass of flower in full bloom (D2) phase was considerable during flower development, in which the contents of longanic acid and gentiopicroside were at the highest levels with 2.65 and 2.88 times higher than those recorded in Chinese Pharmacopoeia 2010, sweroside and swertiamarin in the flowers were reaching 6.06 and 1.25 times higher than those in roots. Florescence is the most valuable stage during flower development. The concentration of Fe, Mg, K, P, and B was higher in the flowers than that in roots. The accumulation of active constituents in the plant was influenced by the contents of metabolically linked carbon and nitrogen compounds. Conclusion: The secondary metabolites, mineral nutrients, and physicochemical indicators are tightly regulated by flower organ development, D2 is an important stage for both biomass and extraction of active constituents such as longanic acid. The flowers of G. macrophylla could be used as a potential medicinal plant part for longanic acid at a high level. © 2014 Tianjin Press of Chinese Herbal Medicines.

Evolutionary conservation of angiosperm flower development at the molecular and genetic levels.

Flowers consist primarily of four basic organ types whose relative positions are universally conserved within the angiosperms. A model has been proposed to explain how a small number of regulatory genes, acting alone and in combination, specify floral organ identity. This model, known widely as the ABC model of flower development, is based on molecular generic experiments in two model organisms, Arabidopsis thaliana and Antirrhinum majus. Both of these species are considered to be eudicots, a clade within the angiosperms with a relatively conserved floral architecture. In this review, the application of the ABC model derived from studies of these typical eudicot species is considered with respect to angiosperms whose floral structure deviates from that of the eudicots. It is concluded that the model is universally applicable to the angiosperms as a whole, and the enormous diversity seen among angiosperms flowers is due to genetic pathways that are downstream, or independent, of the genetic programme that specifies floral organ identity.

Genetic regulation of flower development.

Flower development provides a model system to study mechanisms that govern pattern formation in plants. Most flowers consist of four organ types that are present in a specific order from the periphery to the centre of the flower. Reviewed here are studies on flower development in two model species: Arabidopsis thaliana and Antirrhinum majus that focus on the molecular genetic analysis of homeotic mutations affecting pattern formation in the flower. Based on these studies a model was proposed that explains how three classes of regulatory genes can together control the development of the correct pattern of organs in the flower. The universality of the basic tenets of the model is apparent fromthe analysis of the homologues of the Arabidopsis genes from other plant species.