title: The Antirrhinum AmDEL gene enhances flavonoids accumulation and salt and drought tolerance in transgenic Arabidopsis.
abstract: A basic helix-loop-helix (bHLH) transcription factor gene from Antirrhinum, AmDEL , increases flavonoids accumulation and enhances salt and drought tolerance via up-regulating flavonoid biosynthesis, proline biosynthesis and ROS scavenging genes in transgenic Arabidopsis. In plants, transcriptional regulation is the most important tools for increasing flavonoid biosynthesis. The AmDEL gene, as a basic helix-loop-helix transcription factor gene from Antirrhinum, has been shown to increase flavonoids accumulation in tomato. However, its role in tolerance to abiotic stresses has not yet been investigated. In this study, the codon-optimized AmDEL gene was chemically synthesized. Subcellular localization analysis in onion epidermal cells indicated that AmDEL protein was localized to the nucleus. Expression analysis in yeast showed that the full length of AmDEL exhibited transcriptional activation. Overexpression of AmDEL significantly increased flavonoids accumulation and enhanced salt and drought tolerance in transgenic Arabidopsis plants. Real-time quantitative PCR analysis showed that overexpression of AmDEL resulted in the up-regulation of genes involved in flavonoid biosynthesis, proline biosynthesis and ROS scavenging under salt and drought stresses. Meanwhile, Western blot and enzymatic analyses showed that the activities of phenylalanine ammonia lyase, chalcone isomerase, dihydroflavonol reductase, pyrroline-5-carboxylate synthase, superoxide dismutase and peroxidase were also increased. Further components analyses indicated that the significant increase of proline and relative water content and the significant reduction of H2O2 and malonaldehyde content were observed under salt and drought stresses. In addition, the rates of electrolyte leakage and water loss were reduced in transgenic plants. These findings imply functions of AmDEL in accumulation of flavonoids and tolerance to salt and drought stresses. The AmDEL gene has the potential to be used to increase the content of valuable flavonoids and improve tolerance to abiotic stresses in plants.
authors.affiliation: Shanghai Key Laboratory of Agricultural Genetic Breeding, Biotech Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, 201106, China.
authors.forename: Feibing
authors.initials: F
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University, Beijing, 100193, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Tianjin Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, 300457, China.
authors.forename: Weili
authors.initials: W
authors.lastname: Kong
authors.affiliation: Shanghai Key Laboratory of Agricultural Genetic Breeding, Biotech Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, 201106, China.
authors.forename: Rihe
authors.initials: R
authors.lastname: Peng
authors.affiliation: Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University, Beijing, 100193, China.
authors.forename: Qingchang
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Shanghai Key Laboratory of Agricultural Genetic Breeding, Biotech Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, 201106, China. yaoqh99@163.com.
authors.forename: Quanhong
authors.initials: Q
authors.lastname: Yao
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000222:Adaptation, Physiological / Q000235:genetics; D000595:Amino Acid Sequence; D032161:Antirrhinum / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D055864:Droughts; D005419:Flavonoids / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018613:Microscopy, Confocal; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D009195:Peroxidase / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055049:Salt Tolerance / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism
chemical_list: D000217:Acyltransferases; D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D005419:Flavonoids; D010088:Oxidoreductases; D009195:Peroxidase; D010940:Plant Proteins; D013482:Superoxide Dismutase; C085313:flavonol synthase; C020141:flavanone synthetase
keywords: AmDEL; Antirrhinum; Arabidopsis; Flavonoids; Salt and drought tolerance