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*

Transcription factors, the proteins with special structures, can bind to specific sites and regulate specific expression of target genes. NAC (NAM, ATAF1/2, CUC1/2) transcription factors, unique to plants, are composed of a conserved N-terminal domain and a highly variable C-terminal transcriptional activation domain. NAC transcription factors are involved in plant growth and development, responses to biotic and abiotic stresses and other processes, playing a regulatory role in flower development. In this paper, we reviewed the studies about NAC transcription factors in terms of discovery, structure, and regulatory roles in anther development, other floral organ development and flowering time. This review will provide a theoretical basis for deciphering the regulatory mechanism and improving the regulatory network of NAC transcription factors in flower development.
Flowers/genetics* ; Gene Expression Regulation, Plant ; Phylogeny ; Plant Proteins/metabolism* ; Plants/metabolism* ; Transcription Factors/metabolism*

OBJECTIVETo study the dynamic accumulation of flavonoids in Chrysanthemum morifolium in order to chose the optimal harvest time.

METHODThe flavonoid content was determined in various C. morifolium and in different periods.

RESULT AND CONCLUSIONThe accumulation of flavonoid in various Chrysanthemum reached a high level when lingulate flowers were in 50% blossom and tube ones in 30% or lingulate flowers were in 70% blossom and tube ones in 50%. Only few of C. morifolium reached a high level of flavonoid, when 1 both ingulate and tube flowers blossomed fully.

Chrysanthemum ; metabolism ; Flavones ; Flavonoids ; metabolism ; Flowers ; metabolism ; Medicine, Chinese Traditional ; Time Factors

OBJECTIVETo study the relationships among the main agronomic characters, yield per plant,content of artemisinin of Artemisia annua, and provide the theoretical basis for breeding the A. annua varieties with high-yield and high artemisinin content.

METHODThe main agronomic characters, yield per plant, artemisinin content of the wild and cultivated A. annua of Sichuan province were investigated and determined, and the correlated relationships among them were analyzed.

RESULTIt was showed that the weight of dried stem per plant had very significantly positive correlation with the yield per plant,and the number of primary branches, the diameter of stem had significantly positive correlation with the yield per plant. The flower bud stage, first flowering stage and full-bloom stage had significantly positive correlation with the artemisinin content. The first flowering stage and full-bloom stage had significantly positive correlation with the total artemisinin content per plant. The weight of dried stem per plant,the diameter of stem and the flower bud stage had significantly correlation with the total artemisinin content per plant. A. annua with the purple-stem had significant higher artemisinin content than that with the green-stem. Through the multiple regression analysis, the classic multiple regression equation of the yield per plant was gained as Y = 0.06121-0.000 08X(1) + 0.30378X(3) - 0.00051X(4) - 0.00031X5 (F = 20.15, P < 0.0001), the classic multiple regression equation of the artemisinin content as Y = -1.45849 - 0.00099X(1) - 0.24079X(3) + 0.13362X(6) - 0.00719X(7) + 0.01454X(9) (F = 46.55, P < 0.0001), the classic multiple regression equation of the total artemisinin content per plant as Y = -2.67001 - 0.00249X(1) + 0.98873X(3) + 0.30037X(6) + 0.113X(9) F = 22.62, P < 0.001).

CONCLUSIONThe plant with purple, thick and strong stem, higher plant height, moderate primary branches number and bloom stage, small stem-branch angle should be selected for a breeding new A. annua varieties with high yield and artemisinin content.

Artemisia annua ; chemistry ; growth & development ; metabolism ; Artemisinins ; analysis ; metabolism ; Biomass ; China ; Flowers ; chemistry ; growth & development ; metabolism

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.
Brassica/metabolism* ; Flowers/genetics* ; Gene Expression Regulation, Plant ; MADS Domain Proteins/metabolism* ; Phylogeny ; Plant Proteins/metabolism*

OBJECTIVEPlant metabolomics combined with GC-MS was used to investigate metabolic fingerprinting of Tussilago farfara at different growth stages.

METHODDried Samples were extracted by two-phase solvent system to obtain polar and nonpolar parts, which were subjected to GC-MS analysis. Metabolites were identified by NIST data base search and comparison with the authentic standards. The data were introduced into SIMCA-P 11.0 software package for multivariate analysis after pretreatment.

RESULTFifty-four metabolites were identified, including 35 polar metabolites and 19 nonpolar compounds. The score plot for PCA showed clear separation of the different development stages of flower buds of T. farfara, showing a trend of gradual change. Samples of October, November, December were in close proximity on the plot, indicating that the metabolome of these three periods was similar, samples from September (early development) and March (after flowering) were far away, showing big chemical differences. Content comparison results of some representative metabolites reveals that, the content of proline, lysine and linoleic acid increased gradually to the highest in the medium term, but sharply decreased to the lowest after flowering; the content of malic acid and citric acid were the lowest in the medium term; sucrose content decreased gradually, and then reached the lowest level after blooming.

CONCLUSIONIt is obvious that metabolites of the early development and flowering stage were quite different with those of the traditional harvest time, suggesting that they can not be used as traditional medicine. This study will provide a research basis for harvest time determination and bioactive compounds of T. farfara.

Flowers ; chemistry ; metabolism ; Gas Chromatography-Mass Spectrometry ; Metabolome ; Metabolomics ; Tussilago ; chemistry ; growth & development ; metabolism

OBJECTIVEThis paper aimed to study the dynamic changes of enzyme activities and active component contents in Lonicera japonica during different blossoming stages.

METHODThe enzyme activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD) and the contents of total phenol, total flavonoids, chlorogenic acid, anthocyanins in L. japonica during different blossoming stages were determined.

RESULTThe contents of total phenolics, total flavonoids, anthocyanins decreased from the Sanqing stage to Jinhua stage while the content of chlorogenic acid increased slightly in white period, and then decreased gradually. The activities of three enzymes decreased gradually from Sanqing stage, and got to a minimum value in Yinhua stage, then increased slightly until the Jinhua stage.

CONCLUSIONThe enzyme activities of PPO and POD correlated the content of phenolic substances positively before the Jinhua stage in L. japonica. In the period of maturity, the POD activity was strengthened due to the induction of respiration and became the key enzyme to control active component content during the mature stage.

Catechol Oxidase ; metabolism ; Flowers ; Lonicera ; chemistry ; enzymology ; Peroxidase ; metabolism ; Phenols ; analysis

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

As water-soluble, natural pigments, anthocyanins are responsible for the red, purple and blue colors of many flowers, which attract pollinators to spread pollen. The colors of flowers are also essential for plants to survive in the nature and become one of the most significant characteristics of ornamental plants. In the booming floriculture industry, to produce various flower colors could increase the richness of natural colors, but it is still difficult to breed flowers with coveted blue color. The diversity of flower color is mainly determined by the types and contents of anthocyanins and their derivatives. The synthesis of delphinidin pigments is the key factor for breeding blue flowers. However, there are no structural genes in many plants to biosynthesize delphinidin pigments. Blue flowers are successfully created by genetic engineering in recent years. In this paper, using common ornamental plants as examples, we review the mechanism of plant flower coloration from the aspects of the key factors affecting the synthesis of delphinidin pigment and the production strategies of blue flowers based on the regulation of anthocyanin metabolism. Different strategies of molecular breeding could provide opportunities to improve colors of other floriculture plants and to develop anthocyanin-rich economic crops, such as colored cotton with blue fibers.
Anthocyanins ; metabolism ; Flowers ; Gene Expression Regulation, Plant ; Genetic Engineering ; Pigmentation ; genetics