Sweet potato is an important food crop that can also be used as an industrial raw material. Sucrose is the main form of long-distance carbohydrate transport in plants, and sucrose transporter (SUT) regulates the transmembrane transport and distribution of sucrose during plant growth and metabolism. Moreover, SUT plays a key role in phloem mediated source-to-sink sucrose transport and physiological activities, supplying sucrose for the sink tissues. In this study, the full-length cDNA sequences of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were obtained by rapid amplification of cDNA ends (RACE) cloning according to the transcripts of the two SUT coding genes which were differentially expressed in sweet potato storage roots with different starch properties. Phylogenetic analysis was performed to clarify the classification of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆. The subcellular localization of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ was determined by transient expression in Nicotiana benthamiana. The function of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in sucrose and hexose absorption and transport was identified using yeast functional complementarity system. The expression pattern of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in sweet potato organs were analyzed by real-time fluorescence quantitative PCR (RT-qPCR). Arabidopsis plants heterologous expressing IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ genes were obtained using floral dip method. The differences in starch and sugar contents between transgenic and wild-type Arabidopsis were compared. The results showed IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ encoded SUT proteins with a length of 505 and 521 amino acids, respectively, and both proteins belonged to the SUT1 subfamily. IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were located in the cell membrane and were able to transport sucrose, glucose and fructose in the yeast system. In addition, IbSUT₆₂₇₈₈ was also able to transport mannose. The expression of IbSUT₆₂₇₈₈ was higher in leaves, lateral branches and main stems, and the expression of IbSUT₈₁₆₁₆ was higher in lateral branches, stems and storage roots. After IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ were heterologously expressed in Arabidopsis, the plants grew normally, but the biomass increased. The heterologous expression of IbSUT₆₂₇₈₈ increased the soluble sugar content, leaf size and 1 000-seed weight of Arabidopsis plants. Heterologous expression of IbSUT₈₁₆₁₆ increased starch accumulation in leaves and root tips and 1 000-seed weight of seeds, but decreased soluble sugar content. The results obtained in this study showed that IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ might be important genes regulating sucrose and sugar content traits in sweet potato. They might carry out physiological functions on cell membrane, such as transmembrane transport of sucrose, sucrose into and out of sink tissue, as well as transport and unloading of sucrose into phloem. The changes in traits result from their heterologous expression in Arabidopsis indicates their potential in improving the yield of other plants or crops. The results obtained in this study provide important information for revealing the functions of IbSUT₆₂₇₈₈ and IbSUT₈₁₆₁₆ in starch and glucose metabolism and formation mechanism of important quality traits in sweet potato.
Ipomoea batatas/metabolism* ; Arabidopsis/metabolism* ; Sucrose/metabolism* ; Saccharomyces cerevisiae/metabolism* ; DNA, Complementary ; Phylogeny ; Plants, Genetically Modified/genetics* ; Membrane Transport Proteins/metabolism* ; Starch/metabolism* ; Plant Proteins/metabolism* ; Gene Expression Regulation, Plant

Flavanone 3-hydroxylase (F3H) is a key enzyme in the synthesis of phycocyanidins. In this experiment, the petals of red Rhododendron hybridum Hort. at different developmental stages were used as experimental materials. The R. hybridum flavanone 3-hydroxylase (RhF3H) gene was cloned using reverse transcription PCR (RT-PCR) and rapid-amplification of cDNA ends (RACE) techniques, and bioinformatics analyses were performed. Petal RhF3H gene expression at different developmental stages were analyzed by using quantitative real-time polymerase chain reaction (qRT-PCR). A pET-28a-RhF3H prokaryotic expression vector was constructed for the preparation and purification of RhF3H protein. A pCAMBIA1302-RhF3H overexpression vector was constructed for genetic transformation in Arabidopsis thaliana by Agrobacterium-mediated method. The results showed that the R. hybridum Hort. RhF3H gene is 1 245 bp long, with an open reading frame of 1 092 bp, encoding 363 amino acids. It contains a Fe²⁺ binding motif and a 2-ketoglutarate binding motif of the dioxygenase superfamily. Phylogenetic analysis showed that the R. hybridum RhF3H protein is most closely related to the Vaccinium corymbosum F3H protein. qRT-PCR analysis showed that the expression level of the red R. hybridum RhF3H gene tended to increase and then decrease in the petals at different developmental stages, with the highest expression at middle opening stage. The results of the prokaryotic expression showed that the size of the induced protein of the constructed prokaryotic expression vector pET-28a-RhF3H was about 40 kDa, which was similar to the theoretical value. Transgenic RhF3H Arabidopsis thaliana plants were successfully obtained, and PCR identification and β-glucuronidase (GUS) staining demonstrated that the RhF3H gene was integrated into the genome of A. thaliana plants. qRT-PCR, total flavonoid and anthocyanin contentanalysis showed that RhF3H was significantly higher expressed in the transgenic A. thaliana relative to that of the wild type, and its total flavonoid and anthocyanin content were significantly increased. This study provides a theoretical basis for investigating the function of RhF3H gene, as well as for studying the molecular mechanism of flower color in R. simsiib Planch.
Arabidopsis/metabolism* ; Rhododendron/metabolism* ; Amino Acid Sequence ; Anthocyanins/metabolism* ; Phylogeny ; Flavonoids/metabolism* ; Cloning, Molecular ; Gene Expression Regulation, Plant ; Plant Proteins/metabolism*

SUN gene is a group of key genes regulating plant growth and development. Here, SUN gene families of strawberry were identified from the genome of the diploid Fragaria vesca, and their physicochemical properties, genes structure, evolution and genes expression were also analyzed. Our results showed that there were thirty-one FvSUN genes in F. vesca and the FvSUNs encoded proteins were classified into seven groups, and the members in the same group showed high similarity in gene structures and conservative motifs. The electronic subcellular localization of FvSUNs was mainly in the nucleus. Collinearity analysis showed that the members of FvSUN gene family were mainly expanded by segmental duplication in F. vesca, and Arabidopsis and F. vesca shared twenty-three pairs of orthologous SUN genes. According to the expression pattern in different tissues shown by the transcriptome data of F. vesca, the FvSUNs gene can be divided into three types: (1) expressed in nearly all tissues, (2) hardly expressed in any tissues, and (3) expressed in special tissues. The gene expression pattern of FvSUNs was further verified by quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, the seedlings of F. vesca were treated by different abiotic stresses, and the expression level of 31 FvSUNs genes were assayed by qRT-PCR. The expression of most of the tested genes was induced by cold, high salt or drought stress. Our studies may facilitate revealing the biological function and molecular mechanism of SUN genes in strawberry.
Fragaria/metabolism* ; Genes, Plant ; Stress, Physiological/genetics* ; Arabidopsis/genetics* ; Plant Development ; Gene Expression Regulation, Plant ; Plant Proteins/metabolism*

Chalcone isomerase is a key rate-limiting enzyme in the biosynthesis of flavonoids in higher plants, which determines the production of flavonoids in plants. In this study, RNA was extracted from different parts of Isatis indigotica and reverse-transcribed into cDNA. Specific primers with enzyme restriction sites were designed, and a chalcone isomerase gene was cloned from I. indigotica, named IiCHI. IiCHI was 756 bp in length, containing a complete open reading frame and encoding 251 amino acids. Homology analysis showed that IiCHI was closely related to CHI protein of Arabidopsis thaliana and had typical active sites of chalcone isomerase. Phylogenetic tree analysis showed that IiCHI was classified into type Ⅰ CHI clade. Recombinant prokaryotic expression vector pET28a-IiCHI was constructed and purified to obtain IiCHI recombinant protein. In vitro enzymatic analysis showed that the IiCHI protein could convert naringenin chalcone into naringenin, but could not catalyze the production of liquiritigenin by isoliquiritigenin. The results of real-time quantitative polymerase chain reaction(qPCR) showed that the expression level of IiCHI in the aboveground parts was higher than that in the underground parts and the expression level was the highest in the flowers of the aboveground parts, followed by leaves and stems, and no expression was observed in the roots and rhizomes of the underground parts. This study has confirmed the function of chalcone isomerase in I. indigotica and provided references for the biosynthesis of flavonoid components.
Isatis/genetics* ; Plant Proteins/metabolism* ; Phylogeny ; Arabidopsis/genetics* ; Flavonoids ; Cloning, Molecular

Brassica juncea is a yearly or biennial vegetable in Brassica of Cruciferae. The yield and quality of its product organs are affected by flowering time. WRKY proteins family can respond to biological and abiotic stresses, developmental regulation and signal transduction. WRKY75 is an important member of WRKY family which can regulate flowering, but the flowering regulation mechanism in B. juncea has not been reported. In this study, a gene BjuWRKY75 in B. juncea was cloned, and the encoded-protein belonged to the group Ⅱ of WRKY protein with highly conserved domain. BjuWRKY75 had the highest homology with BriWRKY75 of Brassica nigra. The relative expression level of BjuWRKY75 in flowers was significantly higher than that in leaves and stems, and it was expressed stably in leaves. BjuWRKY75 protein was localized in the nucleus and interacted with the promoter of the flowering integrator BjuFT, which contained the W-box response element for the interaction between protein and DNA. Thus, it could transcriptionally activate the expression of the downstream genes. The overexpression of BjuWRKY75 in Arabidopsis led to earlier flowering significantly. In conclusion, BjuWRKY75 could directly target the promoter of BjuFT and accelerate flowering. These results may facilitate further study on the regulation of flowering molecules of BjuWRKY75.
Arabidopsis/genetics* ; Flowers/genetics* ; Gene Expression Regulation, Plant ; Mustard Plant/genetics* ; Plant Proteins/metabolism* ; Promoter Regions, Genetic

Plant adaptation to adverse environment depends on transmitting the external stress signals into internal signaling pathways, and thus forming a variety of stress response mechanisms during evolution. Brassinosteroids (BRs) is a steroid hormone and widely involved in plant growth, development and stress response. BR is perceived by cell surface receptors, including the receptor brassinosteroid-insensitive 1 (BRI1) and the co-receptor BRI1-associated-kinase 1 (BAK1), which in turn trigger a signaling cascade that leads to the inhibition of BIN2 and activation of BES1/BZR1 transcription factors. BES1/BZR1 can directly regulate the expression of thousands of downstream responsive genes. Studies in the model plant Arabidopsis thaliana have shown that members of BR biosynthesis and signal transduction pathways, particularly protein kinase BIN2 and its downstream transcription factors BES1/BZR1, can be extensively regulated by a variety of environmental factors. In this paper, we summarize recent progresses on how BR biosynthesis and signal transduction are regulated by complex environmental factors, as well as how BR and environmental factors co-regulate crop agronomic traits, cold and salt stress responses.
Arabidopsis/metabolism* ; Brassinosteroids/pharmacology* ; DNA-Binding Proteins/metabolism* ; Gene Expression Regulation, Plant ; Stress, Physiological

Sucrose non-fermenting-1-related protein kinase 2 (SnRK2) is a specific Ser/Thr protein kinase in plants. SnRK2 can regulate the expression of downstream genes or transcription factors through phosphorylation of substrates to achieve stress resistance regulation in different tissue parts, and make plants adapt to adverse environment. SnRK2 has a small number of members and a molecular weight of about 40 kDa, and contains a conserved N-terminal kinase domain and a divergent C-terminal regulatory domain, which plays an important role in the expression of enzyme. This review summarized the recent research progresses on the discovery, structure, and classification of SnRK2, and its function in response to various stresses and in regulating growth and development, followed by prospecting the future research direction of SnRK2. This review may provide a reference for genetic improvement of crop stress resistance.
Abscisic Acid ; Arabidopsis Proteins/genetics* ; Gene Expression Regulation, Plant ; Growth and Development ; Plants/genetics* ; Protein Kinases ; Protein Serine-Threonine Kinases/genetics* ; Stress, Physiological/genetics*

Three-amino acid loop extension (TALE) transcription factors play important roles in plant growth and cell differentiation. There are plenty of studies on TALE transcription factors in several model plants, but not in radish (Raphanus sativas). A genome-wide bioinformatics analysis identified 33 TALE family genes in the Xiang-Ya-Bai (XYB) radish, These genes, are distributed on nine chromosomes and all contain 4-6 exons. The 33 TALE genes in radish showed a co-linearity relationship with the 17 homologous genes in Arabidopsis thaliana. Moreover, a large number of stress response cis-elements were found in the promoter regions of these genes. Expression analysis showed that four genes in the BELL subfamily were highly expressed in roots, and two genes in the KNOX subfamily were highly expressed in shoots of bolting plants and callus. All radish TALE genes contain sequences encoding the conserved HOX domain, except for the gene RSA10037940, which is homologous to Arabidopsis KNATM. The deduced 3D structures of the TALE proteins irrespective of subtypes are highly similar. All the encoded proteins were weakly acidic and hydrophilic. The radish TALE gene family is relatively evolutionarily conserved, which was consistent with results from Arabidopsis, but quite different from that of rice. This study provides important clues for studying the biological functions of TALE transcription factors in radish.
Amino Acids ; Arabidopsis/metabolism* ; Gene Expression Regulation, Plant ; Phylogeny ; Plant Proteins/metabolism* ; Raphanus/metabolism* ; Transcription Factors/metabolism*

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*

Dehydration-responsive element binding proteins (DREBs) are an important class of transcription factors related to plant stress tolerance. Ammopiptanthus mongolicus is an evergreen broadleaf shrub endemic to desert areas of northwest China, and it has a very high tolerance to harsh environments. In order to reveal the functions and mechanisms of the AmDREB1F gene from this species in enduring abiotic stresses, we performed subcellular localization test, expression pattern analysis, and stress tolerance evaluation of transgenic Arabidopsis harboring this gene. The protein encoded by AmDREB1F was localized in the nucleus. In laboratory-cultured A. mongolicus seedlings, the expression of AmDREB1F was induced significantly by cold and drought but very slightly by salt and heat stresses, and undetectable upon ABA treatment. In leaves of naturally growing shrubs in the wild, the expression levels of the AmDREB1F gene were much higher during the late autumn, winter and early spring than in other seasons. Moreover, the expression was abundant in roots and immature pods rather than other organs of the shrubs. Constitutive expression of AmDREB1F in Arabidopsis induced the expression of several DREB-regulated stress-responsive genes and improved the tolerance of transgenic lines to drought, high salinity and low temperature as well as oxidative stress. The constitutive expression also caused growth retardation of the transgenics, which could be eliminated by the application of gibberellin 3. Stress-inducible expression of AmDREB1F also enhanced the tolerance of transgenic Arabidopsis to all of the four stresses mentioned above, without affecting its growth and development. These results suggest that AmDREB1F gene may play positive regulatory roles in response to abiotic stresses through the ABA-independent signaling pathways.
Arabidopsis/metabolism* ; Droughts ; Ectopic Gene Expression ; Fabaceae/genetics* ; Gene Expression Regulation, Plant ; Plant Proteins/metabolism* ; Plants, Genetically Modified/genetics* ; Stress, Physiological/genetics*