Flowering is a critical transitional stage during plant growth and development, and is closely related to seed production and crop yield. The flowering transition is regulated by complex genetic networks, whereas many flowering-related genes generate multiple transcripts through alternative splicing to regulate flowering time. This paper summarizes the molecular mechanisms of alternative splicing in regulating plant flowering from several perspectives, future research directions are also envisioned.
Alternative Splicing/genetics* ; Arabidopsis/metabolism* ; Arabidopsis Proteins/genetics* ; Flowers/genetics*

In this study, 23 germplasm resources of Chrysanthemum morifolium used in medicine and tea were collected from Dabie Mountains and its surrounding producing areas, and the contents of 13 mineral elements were determined and compared. The thermal maps of correlation analysis, principal component analysis and cluster analysis were used for comprehensive evaluation. The results showed that the average content of each element in Ch. morifolium of different germplasm resources was: K>N>P>Mg>Ca>Fe>Mn>Zn>Cu>Ni>Cr>Pb>Cd, and the leaves were: K>N>Ca>Mg>P>Fe>Mn>Zn>Cr>Cu>Ni>Pb>Cd. There are rich contents of N, P, K, Ca, Mg and Fe in Ch. morifolium flowers and their leaves, among them, K element has the largest change range, while N, Ca, Fe, Mg and Zn elements have a larger change range. The absorption and accumulation of each element in the leaves of different germplasm resources varied greatly. The correlation analysis shows that there is a strong positive correlation between Ca element, Mg, Mn and Cd element.Principal component analysis in Ch. morifolium flowers characteristic elements for Mn, Cr, Cu, P, K, can be used as a Ch. morifolium resources to identify the characteristics of the elements, choose top five principal component(F1-F5) comprehensive evalua-tion of medicinal Ch. morifolium, scored in the top five varieties for Hangiu-Fuhuangju, Hangju-Xiaoyangju, Hangju-Sheyangju, Hangju-Dayanghua, Hangju-Subeiju,indicates that in terms of mineral elements, the five medicinal Ch. morifolium resources quality is better. The PCA score chart can divide 23 Ch. morifolium resources into 4 groups, and the cluster analysis heat map divides 23 Ch. morifolium resources into 5 groups. All the Ch. morifolium resources of the same type can be well clustered together, indicating that the difference in mineral element content of Ch. morifolium germplasm resources is closely related to genetic factors.
Chrysanthemum/genetics* ; Flowers/genetics* ; Minerals ; Plant Leaves ; Tea

To identify spatiotemporal expression patterns of vernalization genes in common wheat, we analyzed expression characteristics of several vernalization genes (VRN1, VRN2 and VRN3) in the wheat cultivars 'Chinese spring' and 'Luohan 2' by RT-PCR. The VRN1 gene was expressed at different levels in the leaves and roots at the 3-leaf stage, stems, flag leaves at the grain-filling stage, anthers, ovules, and developing seeds in 'Chinese spring'. Expression of VRN1 increased before flowering date, then decreased after flowering time. Expression of VRN1 was not detected in dry seeds or seeds germination. Expression patterns of VRN1 in 'Luohan 2' were similar to those in 'Chinese spring', except that it was not expressed in roots or in the leaves at the 3-leaf stage in 'Luohan 2'. Expression of VRN2 was only detected in the leaves at the 3-leaf stage and in the embryo buds during seeds germination. The Spatiotemporal expression of VRN3 was similar to that of VRN1, except that VRN3 was not expressed in roots. These results improved our understanding of the molecular regulation of vernalization genes in common wheat.
Flowers ; genetics ; physiology ; Gene Expression Regulation, Plant ; genetics ; Genes, Plant ; genetics ; Triticum ; genetics

HDA9, a member of the deacetylase family, plays a vital role in regulating plant flowering time through flowering integrator SOC1 and AGL24. However, it remains elusive how HDA9 interacts with SOC1 and AGL24 in flowering time control. Here, HDA9 was cloned in Brassica juncea and then its three active sites were separately replaced with Ala via overlap extension PCR. Thus, mutants of HDA9(D172A), HDA9(H174A) and HDA9(D261A) were constructed and fused into the pGADT7 vector. The yeast one-hybrid assays indicated that HDA9 mutants remained the interactions with the promoters of SOC1 and AGL24. Furthermore, the aforementioned results were confirmed in the dual luciferase assays. Interestingly, the DNA-protein interactions were weakened significantly due to the mutation in the three active sites of HDA9. It suggested that flowering signal integrator SOC1 and AGL24 were regulated by the key amino acid residues of 172th, 174th and 261th in HDA9. Our results provide valuable information for the in-depth study of the biological function and molecular regulation of HDA9 in Brassica juncea flowering time control.
Flowers ; genetics ; Gene Expression Regulation, Plant ; genetics ; Mustard Plant ; enzymology ; genetics ; Mutation ; Plant Proteins ; genetics ; metabolism ; Promoter Regions, Genetic ; genetics

In order to study the regulation mechanism of secondary metabolites biosynthesis in Lonicera macranthoides, the key genes involved in the regulation of biosynthesis and the mechanism of differential metabolites were explored. In this study, high-throughput sequencing technology was used for transcriptome sequencing of L. macranthoides at different development stages. By using Liquid chromatography-tandem mass spectrometry(LC-MS/MS) technology, the laws of qualitative, quantitative and synthetic accumulation of its metabolites were studied, and the key enzyme genes for the biosynthesis of phenolic acid and flavonoids were screened out according to the differentially expressed genes. A total of 111 differentially accumulate metabolites(DAM) and 6 653 differentially expressed genes(DGE) were obtained by metabonomics and transcriptomics analysis. The metabolites and key enzyme genes in the Erqing(KE) were significantly different from those in the Dabai(KD) and Yinhua(KY) stages. In the phenylalanine biosynthesis pathway, the ion abundance of chlorogenic acid, naringin, quercetin, rutin, coniferol and other metabolites decreased with the development of flowers, while the ion abundance of ferulic acid, coumarin and syringoside increased with the development of flowers. Key enzyme genes such as CHS, HCT, CCR, FLS and COMT positively regulate the downstream metabolites, while PAL, C4H and 4CL negatively regulate the downstream metabolites. This study provides candidate genes and theoretical basis for the further exploration of key enzymes in the biosynthesis of secondary metabolites and for the regulation of the accumulation of secondary metabolites in L. macranthoides by molecular biological methods.
Chromatography, Liquid ; Flowers/genetics* ; Lonicera/genetics* ; Metabolomics ; Proteomics ; Tandem Mass Spectrometry

MYB transcription factor is one of the largest transcription families and involved in plant growth and development, stress response, product metabolism and other processes. It regulates the development of plant flowers, especially anther development, a key role in the reproduction of plant progeny. Here, we discuss the regulatory effects of MYB transcription factors on the development of anther, including tapetum development, anther dehiscence, pollen development, carbohydrates and hormone pathways. We provide a reference for the further study of the regulation mechanism and network of plant anther development.
Arabidopsis/metabolism* ; Flowers/genetics* ; Gene Expression Regulation, Plant ; Humans ; Pollen/genetics* ; Reproduction ; Transcription Factors/metabolism*

Photoperiod plays an important role in transformation from vegetative growth to reproductive growth in plants. CONSTANS (CO), as a unique gene in the photoperiod pathway, responds to changes of day length to initiate flowering in the plant. In this study, the expression level of FaCONSTANS (FaCO) gene under long-day, short-day, continuous light and continuous darkness conditions was analyzed by real-time quantitative PCR. We constructed the over-expression vector p1300-FaCO and infected into Arabidopsis thaliana by Agrobacterium-mediated method. We constructed the silencing vector p1300-FaCO-RNAi and infected into Festuca arundinacea by Agrobacterium-mediated method. The expression of FaCO gene was regulated by photoperiod. The over-expression of FaCO promoted flowering in wild type of Arabidopsis thaliana under long day condition and rescued the late flowering phenotype in co-2 mutant of Arabidopsis thaliana. Silencing FaCO gene in Festuca arundinacea by RNAi showed late-flowering phenotype or always kept in the vegetative growth stage. Our understanding the function of FaCO in flowering regulation will help further understand biological function of this gene in Festuca arundinacea.
Arabidopsis/metabolism* ; Arabidopsis Proteins/genetics* ; Festuca/metabolism* ; Flowers/genetics* ; Gene Expression Regulation, Plant ; Photoperiod

In order to enrich the transcriptome data of Fagopyrum dibotrys plants, analyze the genes encoding key enzyme involved in flavonoid biosynthesis pathway, and mine their functional genes, in this study, we performed RNA sequencing analysis for the rhizomes, roots, flowers, leaves and stems of F. dibotrys on the BGISEQ-500 sequencing platform. After de novo assembly of transcripts, a total of 205 619 unigenes were generated and 132 372 unigenes were obtained and annotated into seven public databases, of which, 81 327 unigenes were mapped to the GO database and most of the unigenes were annotated in cellular process, biological regulation, binding and catalytic activity. Besides, 86 922 unigenes were enriched in 136 pathways using KEGG database' and we identified 82 unigenes that encodes key enzymes involved in flavonoid biosynthesis. Comparing rhizome with root, flower, leaf or stem in F. dibotrys, 27 962 co-expressed differentially expressed genes(DEGs) were obtained. Among them, 23 515 DEGs of rhizome tissue-specific were enriched into 132 pathways and 13 unigenes were significantly enriched in biosynthesis of flavone and flavonol. In addition, we also identified 3 427 unigenes encoding 60 transcription factor(TFs) families as well as four unigenes encoding bHLH TFs were enriched in flavonoid biosynthesis. Our results greatly enriched the transcriptome database of plants, provided a reference for the analysis of key enzymes involved in flavonoid biosynthesis in plants, and will facilitate the study of the functions and regulatory mechanisms of key enzymes involved in flavonoid biosynthesis in F. dibotrys at the genetic level.
Biosynthetic Pathways/genetics* ; Fagopyrum ; Flavonoids ; Flowers ; Gene Expression Profiling ; Gene Expression Regulation, Plant ; Humans ; Transcriptome/genetics*

Phenylalaninammo-nialyase (PAL) is a key enzyme in the synthesis of methyl benzoate - a plant aroma compound. In order to understand the function of this enzyme in the formation of fragrance in the scented Rhododendron species-Rhododendron fortunei, we cloned a gene encoding this enzyme and subsequently examined the gene expression patterns and the profile of enzyme activity during development in various tissues. The full length of RhPAL gene was cloned by reverse transcription-PCR (RT-PCR) and rapid amplification of cDNA ends (RACE) techniques. The expression levels of RhPAL gene were measured by real-time quantitative reverse transcription PCR (qRT-PCR) and the amount of phenylalanine and cinnamic acid were assayed with LC-MS. The results showed that the ORF sequence of RhPAL gene amplified from the cDNA templates of flower buds had 2 145 bp, encoding 715 amino acids, and shared 90% homology to the PAL amino acid sequences from other species. qRT-PCR analysis showed that the expression of RhPAL in petals during flowering kept in rising even until the flowers wilted. The expression of RhPAL in pistil was much higher than that in stamen, while the expression in the younger leaves was higher than in old leaves. However, the expression level was relatively lower in petal and stamen compared to that in leaves. We also measured the PAL activity by Enzyme-linked immuno sorbent assay in the petals of flowers at different flowering stages. The results showed that PAL activity reached the highest at the bud stage and then decreased gradually to the lowest when the flowers wilted, which followed a similar trend in the emission of the flower fragrance. The phenylalanine and cinnamic acid contents measured by LC-MS were highly correlated to the expression level of RhPAL in various tissues and at different flowering stages, implying that RhPAL plays an important role in the formation of the flower fragrance. This work may facilitate the breeding and improvement of new fragrant Rhododendron cultivars.
Amino Acid Sequence ; Cloning, Molecular ; DNA, Complementary ; Flowers/genetics* ; Rhododendron/genetics*

'Zhizhang Guhong Chongcui' is a new cultivar of Prunus mume with cross-cultivar group characteristics. It has typical characteristics of cinnabar purple cultivar group and green calyx cultivar group. It has green calyx, white flower, and light purple xylem, but the mechanism remains unclear. In order to clarify the causes of its cross-cultivar group traits, the color phenotype, anthocyanin content and the expression levels of genes related to anthocyanin synthesis pathway of 'Zhizhang Guhong Chongcui', 'Yuxi Zhusha' and 'Yuxi Bian Lü'e' were determined. It was found that the red degree of petals, sepals and fresh xylem in branches was positively correlated with the total anthocyanin content. MYBɑ1, MYB1, and bHLH3 were the key transcription factor genes that affected the redness of the three cultivars of flowers and xylem. The transcription factors further promoted the high expression of structural genes F3'H, DFR, ANS and UFGT, thereby promoting the production of red traits. Combined with phenotype, anthocyanin content and qRT-PCR results, it was speculated that the white color of petals of 'Zhizhang Guhong Chongcui' were derived from the high expression of FLS, F3'5'H, LAR and ANR genes in other branches of cyanidin synthesis pathway, and the low expression of GST gene. The green color of sepals might be originated from the relatively low expression of F3'H, DFR and ANS genes. The red color of xylem might be derived from the high expression of ANS and UFGT genes. This study made a preliminary explanation for the characteristics of the cross-cultivar group of 'Zhizhang Guhong Chongcui', and provided a reference for molecular breeding of flower color and xylem color of Prunus mume.
Animals ; Anthocyanins ; DNA Shuffling ; Flowers/genetics* ; Porifera ; Prunus/genetics* ; Glutamine/analogs & derivatives* ; Plant Extracts