title: Genetic analysis of phytoene synthase 1 (Psy1) gene function and regulation in common wheat.
abstract: Phytoene synthase 1 (PSY1) is the most important regulatory enzyme in carotenoid biosynthesis, whereas its function is hardly known in common wheat. The aims of the present study were to investigate Psy1 function and genetic regulation using reverse genetics approaches.
  
  
  
  Transcript levels of Psy1 in RNAi transgenic lines were decreased by 54-76 % and yellow pigment content (YPC) was reduced by 26-35 % compared with controls, confirming the impact of Psy1 on carotenoid accumulation. A series of candidate genes involved in secondary metabolic pathways and core metabolic processes responded to Psy1 down-regulation. The aspartate rich domain (DXXXD) was important for PSY1 function, and conserved nucleotides adjacent to the domain influenced YPC by regulating gene expression, enzyme activity or alternative splicing. Compensatory responses analysis indicated that three Psy1 homoeologs may be coordinately regulated under normal conditions, but separately regulated under stress. The period 14 days post anthesis (DPA) was found to be a key regulation node during grain development.
  
  
  
  The findings define key aspects of flour color regulation in wheat and facilitate the genetic improvement of wheat quality targeting color/nutritional specifications required for specific end products.
authors: Institute of Crop Science, National Wheat Improvement Center, Chinese Academy of Agricultural Sciences (CAAS), 12 Zhongguancun South Street, Beijing, 100081, China.
authors: Shengnan
authors: S
authors: Zhai
authors: Crop Research Institute, Shandong Academy of Agricultural Sciences, 202 Gongye Bei Road, Jinan, Shandong, 250100, China.
authors: Genying
authors: G
authors: Li
authors: Institute of Crop Science, National Wheat Improvement Center, Chinese Academy of Agricultural Sciences (CAAS), 12 Zhongguancun South Street, Beijing, 100081, China.
authors: Youwei
authors: Y
authors: Sun
authors: Crop Research Institute, Shandong Academy of Agricultural Sciences, 202 Gongye Bei Road, Jinan, Shandong, 250100, China.
authors: Jianmin
authors: J
authors: Song
authors: Institute of Crop Science, National Wheat Improvement Center, Chinese Academy of Agricultural Sciences (CAAS), 12 Zhongguancun South Street, Beijing, 100081, China.
authors: Jihu
authors: J
authors: Li
authors: Crop Research Institute, Shandong Academy of Agricultural Sciences, 202 Gongye Bei Road, Jinan, Shandong, 250100, China.
authors: Guoqi
authors: G
authors: Song
authors: Crop Research Institute, Shandong Academy of Agricultural Sciences, 202 Gongye Bei Road, Jinan, Shandong, 250100, China.
authors: Yulian
authors: Y
authors: Li
authors: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
authors: Hongqing
authors: H
authors: Ling
authors: Institute of Crop Science, National Wheat Improvement Center, Chinese Academy of Agricultural Sciences (CAAS), 12 Zhongguancun South Street, Beijing, 100081, China. zhhecaas@163.com.|International Maize and Wheat Improvement Center (CIMMYT) China Office, c/o CAAS, 12 Zhongguancun South Street, Beijing, 100081, China. zhhecaas@163.com.
authors: Zhonghu
authors: Z
authors: He
authors: Institute of Crop Science, National Wheat Improvement Center, Chinese Academy of Agricultural Sciences (CAAS), 12 Zhongguancun South Street, Beijing, 100081, China. xiaxianchun@caas.cn.
authors: Xianchun
authors: 0000-0003-2071-197X
authors: X
authors: Xia
mesh_terms: D000595:Amino Acid Sequence; D018506:Gene Expression Regulation, Plant; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010858:Pigmentation / Q000235:genetics*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012639:Seeds / Q000502:physiology; D016415:Sequence Alignment; D014908:Triticum / Q000201:enzymology* / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase
keywords: Carotenoid biosynthesis; RNA-Seq; RNAi; TILLING; Triticum aestivum