title: FcWRKY70, a WRKY protein of Fortunella crassifolia, functions in drought tolerance and modulates putrescine synthesis by regulating arginine decarboxylase gene.
abstract: WRKY comprises a large family of transcription factors in plants, but most WRKY members are still poorly understood. In this study, we report functional characterization of a Group III WRKY gene (FcWRKY70) from Fortunella crassifolia. FcWRKY70 was greatly induced by drought and abscisic acid, but slightly or negligibly by salt and cold. Overexpression of FcWRKY70 in tobacco (Nicotiana nudicaulis) and lemon (Citrus lemon) conferred enhanced tolerance to dehydration and drought stresses. Transgenic tobacco and lemon exhibited higher expression levels of ADC (arginine decarboxylase), and accumulated larger amount of putrescine in comparison with wild type (WT). Treatment with D-arginine, an inhibitor of ADC, caused transgenic tobacco plants more sensitive to dehydration. Knock-down of FcWRKY70 in kumquat down-regulated ADC abundance and decreased putrescine level, accompanied by compromised dehydration tolerance. The promoter region of FcADC contained two W-box elements, which were shown to be interacted with FcWRKY70. Taken together, our data demonstrated that FcWRKY70 functions in drought tolerance by, at least partly, promoting production of putrescine via regulating ADC expression.
authors: Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Xiaoqing
authors: X
authors: Gong
authors: Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Jingyan
authors: J
authors: Zhang
authors: Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Jianbing
authors: J
authors: Hu
authors: Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Wei
authors: W
authors: Wang
authors: Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Hao
authors: H
authors: Wu
authors: Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Qinghua
authors: Q
authors: Zhang
authors: Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China.
authors: Ji-Hong
authors: JH
authors: Liu
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics; D000595:Amino Acid Sequence; D001120:Arginine / Q000494:pharmacology; D002262:Carboxy-Lyases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002957:Citrus / Q000235:genetics; D055864:Droughts; D059372:Nucleotide Motifs; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000502:physiology; D011401:Promoter Regions, Genetic; D011700:Putrescine / Q000096:biosynthesis*; D027821:Rutaceae / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016415:Sequence Alignment; D013312:Stress, Physiological; D014026:Nicotiana / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D001120:Arginine; D002262:Carboxy-Lyases; C019722:arginine decarboxylase; D011700:Putrescine
keywords: Kumquat abiotic stress; polyamine biosynthesis; transcriptional regulation