The PIF7 gene is a member of the bHLH family, playing a pivotal role in plant germination. However, its roles in tea plants (Camellia sinensis) remain largely unexplored. In this study, we cloned the phytochrome-interacting factor gene CsPIF7 to elucidate its role in the germination of tea plants. Subcellular localization analysis demonstrated that CsPIF7 was localized in the nucleus. Yeast one-hybrid and dual-luciferase reporter assays demonstrated that CsPIF7 directly bound to a specific region (7-321 bp) of the CsEXP promoter, thereby repressing the expression of CsEXP. These findings suggest that CsPIF7 may modulate the germination of tea plants by inhibiting the expression of CsEXP. Quantitative real-time PCR results showed that both CsPIF7 and CsEXP exhibited high expression levels in tea buds, with different expression patterns in response to abscisic acid (ABA) treatment. Furthermore, both CsPIF7 and CsEXP were upregulated under cold stress at 4 ℃, indicating their involvement in the cold response of tea plants. Taken together, these results suggest that CsPIF7 regulates CsEXP expression in an ABA-dependent manner, thereby influencing the germination of tea plants. This study provides both theoretical and experimental insights into the molecular mechanisms governing the germination of tea plants, laying the groundwork for further exploring the role of PIF7 in plant development and stress responses.
Camellia sinensis/metabolism* ; Gene Expression Regulation, Plant ; Plant Proteins/metabolism* ; Abscisic Acid/pharmacology* ; Germination/genetics* ; Basic Helix-Loop-Helix Transcription Factors/metabolism* ; Promoter Regions, Genetic ; Cold Temperature

Gelsemium elegans, a vine plant of Loganiaceae, has both medicinal and forage values. However, it is susceptible to low temperatures during growth. Exploring low temperature response genes is of great significance for cold resistance breeding of G. elegans. Ethylene response factors (ERFs) are the transcription factors of the AP2/ERF superfamily and play a crucial role in plant stress response. In this study, based on the unigene GeERF involved in the response to low temperature stress in the transcriptome of G. elegans, a full-length cDNA sequence of the transcription factor GeERF4B-1 was cloned from the leaves of G. elegans by reverse transcription-polymerase chain reaction (RT-PCR). Bioinformatics analysis showed that GeERF4B-1 had an open reading frame of 759 bp, encoding a protein composed of 252 amino acid residues and with a relative molecular weight of 27 kDa. The deduced protein was predicted to be an unstable, alkaline, and hydrophilic protein. The phylogenetic tree showed that GeERF4B-1 was in the same clade as the B-4 subfamily of the ERF family. The results of the subcellular localization experiment revealed that GeERF4B-1 was located in the nucleus. Real time quantitative PCR (RT-qPCR) analysis indicated that GeERF4B-1 was expressed in the root, stem, and leaf of G. elegans, with the highest expression level in the root. Compared with the control, the treatments with a low temperature (4 ℃), methyl jasmonate (MeJA), and abscisic acid (ABA) up-regulated the expression level of GeERF4B-1, which reached the peak at 24-48 h. This result revealed that GeERF4B-1 actively responded to low temperature, MeJA, and ABA stresses. However, both sodium chloride (NaCl) and drought treatments down-regulated the expression of GeERF4B-1. In addition, a prokaryotic expression vector of GeERF4B-1 was constructed, and a fusion protein of approximately 52 kDa was yielded after induced expression. The results of the plate stress assay showed that compared with the control, the prokaryotic strain expressing GeERF4B-1 demonstrated enhanced tolerance to low temperatures and sensitivity to salt and mannitol stresses. This study provides theoretical references and potential genetic resources for breeding G. elegans varieties with stress resistance.
Transcription Factors/metabolism* ; Plant Proteins/metabolism* ; Gelsemium/metabolism* ; Acetates/pharmacology* ; Gene Expression Regulation, Plant ; Phylogeny ; Cold Temperature ; Amino Acid Sequence ; Cyclopentanes/metabolism* ; Oxylipins/metabolism* ; Stress, Physiological/genetics* ; Abscisic Acid/metabolism* ; Cloning, Molecular

Seed vigor is a key factor affecting seed quality. The mechanical drying process exerts a significant influence on rice seed vigor. The initial moisture content (IMC) and drying temperature are considered the main factors affecting rice seed vigor through mechanical drying. This study aimed to determine the optimum drying temperature for rice seeds according to the IMC, and elucidate the mechanisms mediating the effects of drying temperature and IMC on seed vigor. Rice seeds with three different IMCs (20%, 25%, and 30%) were dried to the target moisture content (14%) at four different drying temperatures. The results showed that the drying temperature and IMC had significant effects on the drying performance and vigor of the rice seeds. The upper limits of drying temperature for rice seeds with 20%, 25%, and 30% IMCs were 45, 42, and 38 °C, respectively. The drying rate and seed temperature increased significantly with increasing drying temperature. The drying temperature, drying rate, and seed temperature showed extremely significant negative correlations with germination energy (GE), germination rate, germination index (GI), and vigor index (VI). A high IMC and drying temperature probably induced a massive accumulation of hydrogen peroxide (H₂O₂) and superoxide anions in the seeds, enhanced superoxide dismutase (SOD) and catalase (CAT) activity, and increased the abscisic acid (ABA) content. In the early stage of seed germination, the IMC and drying temperature regulated seed germination through the metabolism of H₂O₂, gibberellin acid (GA), ABA, and α-amylase. These results indicate that the metabolism of reactive oxygen species (ROS), antioxidant enzymes, GA, ABA, and α-amylase might be involved in the mediation of the effects of drying temperature on seed vigor. The results of this study provide a theoretical basis and technical guidance for the mechanical drying of rice seeds.
Abscisic Acid/metabolism* ; Antioxidants/pharmacology* ; Catalase/metabolism* ; Gene Expression Regulation, Plant/drug effects* ; Germination ; Gibberellins/metabolism* ; Hydrogen Peroxide/chemistry* ; Malondialdehyde/chemistry* ; Oryza/metabolism* ; Oxygen/chemistry* ; Plant Proteins/genetics* ; Reactive Oxygen Species ; Seeds/metabolism* ; Superoxide Dismutase/metabolism* ; Superoxides/chemistry* ; Temperature ; Weather ; alpha-Amylases/metabolism*

To investigate roles of nitric oxide (NO) signal in accumulations of phenolic acids in abscisic.acid (ABA)-induced Salvia miltiorrhiza hairy roots, S. miltiorrhiza hairy roots were treated with different concentrations of sodium nitroprusside (SNP)-an exogenous NO donor, for 6 days, and contents of phenolic acids in the hairy roots are determined. Then with treatment of ABA and NO scavenger (2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethylimidazoline-1- oxyl-3-oxide, c-PTIO) or NO synthase inhibitor (NG-nitro-L-arginine methyl ester, L-NAME), contents of phenolic acids and expression levels of three key genes involved in phenolic acids biosynthesis were detected. Phenolic acids production in S. miltiorrhiza hairy roots was most significantly improved by 100 µmoL/L SNP. Contents of RA and salvianolic acid B increased by 3 and 4 folds. ABA significantly improved transcript levels of PAL (phenylalanine ammonia lyase), TAT (tyrosine aminotransferase) and RAS (rosmarinic acid synthase), and increased phenolic acids accumulations. However, with treatments of ABA+c-PTIO or ABA+L-NAME, accumulations of phenolic acids and expression levels of the three key genes were significantly inhibited. Both NO and ABA can increase accumulations of phenolic acids in S. miltiorrhiza hairy roots. NO signal probably mediates the ABA-induced phenolic acids production.
Abscisic Acid ; pharmacology ; Benzofurans ; metabolism ; Free Radical Scavengers ; pharmacology ; Hydroxybenzoates ; metabolism ; Nitric Oxide ; metabolism ; Phenylalanine Ammonia-Lyase ; metabolism ; Plant Roots ; metabolism ; Salvia miltiorrhiza ; metabolism ; Tyrosine Transaminase ; metabolism

An experiment was conducted using cultivated Glycyrrhiza uralensis in age of one year to study the effects of abscisic acid (ABA) on chemical components content and color of G. uralensis. By using different concentrations of ABA spraying on leaves, the change of the chemical component content was analyzed within 45 d after ABA stimulation, and the effects on quality were studied combined with colorimetric analysis data. It turned out that in some sense the content of glycyrrhizic acid and liquiritin had increased within 45 d, especially for liquiritin. After high concentrations of ABA (3.96 mg · L(-1)) stimulating, the content of glycyrrhizic acid rose 52% while liquiritin up 392% within 30 d. Then they both showed a decline in the content of glycyrrhizic acid and liquiritin on 45 d. Color index values of a* and b* were all significantly higher than that of the control group within 45 d, which meant the color of powders turned toward red and yellow. The conclusion was that ABA (3.96 mg · L(-1)) stimulating could not only improve the quality in the traditional sense through the color of G. uralensis, but also in the modern sense by improving the content of glycyrrhizic acid and liquiritin.
Abscisic Acid ; pharmacology ; Color ; Drugs, Chinese Herbal ; chemistry ; Flavanones ; analysis ; Glucosides ; analysis ; Glycyrrhiza uralensis ; chemistry ; drug effects ; growth & development ; Glycyrrhizic Acid ; analysis ; Plant Growth Regulators ; pharmacology

Using universal primer Tyl-copia retrotransposon RT, the conserved reverse transcriptase domain of about 260 bp was amplified by RT-PCR from the Dendrobium officinale which induced by 100 micromol x L(-1) abscisic acid (ABA), indicating these retrotransposons activated by 100 micromol x L(-1) ABA. The amplicons were recovered and cloned,then sequenced and analyzed by related bioinformatics software. Forty-two Ty1-copia like retrotransposon RT transcriptionally activated were obtained with high heterogeneity. The length of these sequences varied from 247 to 266 bp, and was rich in AT and homology ranged from 46.3% to 98.9%. The same to Ty1-copia like retrotransposon RT of genome, different c/s-acting regulatory elements induced by stress conditions and the starting transcription signals, corresponding to CAAT box, TATA box conserved sequences and some other regulatory elements. The c/s-acting regulatory elements induced by stress conditions of reverse transcriptase transcriptionally activated of Tyl-copia retrotransposons were significantly increased than that of Ty1-copia like retrotransposon RT of genome. When being translated into amino acids, fifteen sequences presented stop codon mutation, nineteen sequences presented frameshift mutation, and all sequences presented conserved sequence "SLYGKQ" mutation. Five categories were identified through phylogenic analysis after alignment analyses of their amino acid sequences, and with Ty1-copia like retrotransposon RT of genome having low homology, which indicated that reverse transcriptase transcriptionally activated of Ty1-copia retrotransposons which induced by ABA had Significantly differences with Ty1-copia like retrotransposon RT of genome.
Abscisic Acid ; pharmacology ; Amino Acid Sequence ; Dendrobium ; drug effects ; genetics ; Molecular Sequence Data ; Phylogeny ; Retroelements ; drug effects ; Sequence Homology, Amino Acid ; Transcription, Genetic ; drug effects

In order to investigate biological functions of the 14-3-3 genes and their response to abiotic stress, two cDNAs (designated as Ta14R1 and Ta14R2) encoding putative 14-3-3 proteins were isolated from wheat by PCR and rapid amplification of cDNA end (RACE) technique. The cDNA of Ta14R1 is 999bp and encodes a protein of 262 amino acids, while the cDNA of Ta14R2 is 897bp in length and encodes a protein of 261 amino acids. Transient expression assays using Ta14R1/Ta14R2-GFP fusion constructs indicated that Ta14R1 and Ta14R2 were located in cytoplasm and cell membrane but not in chloroplasts. Real-time quantitative (RT-PCR) analysis revealed that Ta14R1 and Ta14R2 were differentially expressed in wheat tissues and significantly up-regulated in roots and shoots 1d after germination, indicating they may play a role in process of seed germination. The expression of the two genes in roots and leaves were significantly induced by plant hormone ABA, as well as heat, cold and drought treatments, suggesting that the two 14-3-3 genes in wheat may be involved in ABA dependent stress-responding pathway and response to heat, cold and drought stress.
14-3-3 Proteins ; genetics ; Abscisic Acid ; pharmacology ; DNA, Complementary ; Droughts ; Gene Expression Regulation, Plant ; Genes, Plant ; Germination ; Plant Leaves ; genetics ; physiology ; Plant Roots ; genetics ; physiology ; Stress, Physiological ; Temperature ; Triticum ; genetics ; physiology

OBJECTIVETo study the seeds dormancy release and physiological change of Thesium chinense.

METHODTo release dormancy, the seeds of T. chinense were treated with chemical reagent and stratification under 3-5 degrees C.

RESULTWhen washed with flowing water for 24 h, then soaked in 500 mg x L(-1) GA3 for 24 h, finally, treated with stratification method under 3-5 degrees C for 150 day, the split rate of T. chinense seeds reached 22%, crude fat decreased 50%, total sugar and dissolvability sugar increased 3-4 times, ABA decreased more than 90%, GA3 increased more than 5 times.

CONCLUSIONThe seeds dormancy of T. chinense can be released with the method of washing with flowing water for 24 h, then soaking in 500 mg x L(-1) GA3 for 24 h, finally, treated with stratification method under 3-5 degrees C for 150-180 day.

Abscisic Acid ; pharmacology ; Carbohydrates ; analysis ; Cold Temperature ; Fats ; analysis ; Germination ; physiology ; Gibberellins ; pharmacology ; Magnoliopsida ; drug effects ; physiology ; Plant Dormancy ; drug effects ; physiology ; Plant Growth Regulators ; pharmacology ; Plants, Medicinal ; drug effects ; physiology ; Seeds ; drug effects ; physiology ; Time Factors ; Water ; pharmacology

OBJECTIVETo study the function of ABA and fluridone on the contents of penolic acids and two key synthetases (PAL and TAT).

METHODConducted 4 different concentrations in the hairy root of Salvia miltiorrhiza after culturing 18 days and treated with fluridone. One day later, harvested the hairy root and measured the activity of PAL and TAT; Treatment for 6 days, gathered and determined the contents of phenolic acids.

RESULTIn certain concentration of ABA, lower ABA could induced the production of growth and higher ABA inhibitor the growth in hairy roots of S. miltiorrhiza; ABA induced the accumulation of caffeic acid considerably, and the effect on the contents of coffee acid show positive correlation; As for the RA and LAB, the low dosage of ABA simulated the production and higher ABA inhibited the production of them; the ABA biosynthetic inhibitor fluridone can decreases ABA's the effect; The different of ABA activated the activity of PAL and TAT, but the impact were discriminating, when treatment with ABA and fluridone, the inducing were declined.

CONCLUSIONABA induced the accumulation of.

Abscisic Acid ; antagonists & inhibitors ; metabolism ; pharmacology ; Antioxidants ; analysis ; metabolism ; Biomass ; Caffeic Acids ; analysis ; metabolism ; Herbicides ; pharmacology ; Hydroxybenzoates ; analysis ; metabolism ; Medicine, Chinese Traditional ; Phenylalanine Ammonia-Lyase ; drug effects ; metabolism ; Plant Roots ; drug effects ; enzymology ; growth & development ; Pyridones ; pharmacology ; Salvia miltiorrhiza ; drug effects ; enzymology ; growth & development ; Time Factors ; Tyrosine Transaminase ; drug effects ; metabolism

The effect of sugars, gibberellic acid (GA3) and abscisic acid (ABA) on somatic embryogenesis from internodal explant-derived callus of Tylophora indica (Burm. f.) Merrill has been investigated. Embryogenic calli were produced from internodal explants and the best result was achieved by using MS medium supplemented with 4micromol/L 2, 4-Dichlorophenoxyacetic acid (2, 4-D). Up to 69% of such embryogenic calli differentiated into somatic embryos with an average of 25 embryos per explant (per gram of the calli) on Murashige and Skoog (MS) medium containing 6micromol/L kinetin (Kn). The individual effect of sucrose and glucose together with 6micromol/L Kn was evaluated. There was a significant difference among concentrations of sugar and among kinds of sugar tested in somatic embryogenesis. Sucrose at 200mmol/L with 6micromol/L Kn gave rise to a maximum embryogenesis (71%) with an average of 49 embryos per explant. However, glucose together with 6micromol/L Kn or a combination of glucose, sucrose and 6micromol/L Kn reduced the percentage of embryogenesis culture and the number of embryos per explant. The presence of GA3 and ABA at particular concentrations promoted somatic embryogenesis in T. indica. The addition of 10mol/L GA3 into the 200mmol/L sucrose-containing medium gave a 98% embryogenesis response with an average of 51 embryos per explant. Somatic embryogenesis was significantly enhanced by the addition of 2micromol/L ABA to 200mmol/L sucrose-containing medium. On this medium 95% embryogenesis with an average of 44 embryos per explant was observed. The study reported here indicates that 200mmol/L sucrose with 6micromol/L Kn, 200mmol/L sucrose with 10micromol/L GA3 and 200mmol/L sucrose with 2micromol/L ABA significantly improved somatic embryogenesis in T. indica whereas glucose alone or in combination with sucrose had an inhibitory role. The embryos obtained developed normally and were easily converted into plants.
Abscisic Acid ; pharmacology ; Carbohydrates ; pharmacology ; Culture Media ; Culture Techniques ; Gibberellins ; pharmacology ; Plant Shoots ; embryology ; growth & development ; Tylophora ; embryology ; growth & development