Identification and characterization of a novel copper transporter gene family TaCT1 in common wheat

• Published in: Plant, cell and environment Vol. 37; no. 7; pp. 1561 - 1573
• Main Authors: LI, HAOXUN, FAN, RENCHUN, LI, LIBIN, WEI, BO, LI, GUOLIANG, GU, LIQING, WANG, XIANPING, ZHANG, XIANGQI
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Science 01.07.2014; Blackwell; Wiley Subscription Services, Inc
• Subjects: Amino Acids - metabolism; Base Sequence; Biological and medical sciences; Biological Transport - drug effects; chromosomes; Chromosomes, Plant - genetics; copper; Copper - metabolism; Copper - toxicity; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant - drug effects; Gene Knockdown Techniques; gene silencing; genes; Genes, Plant; Genetic Complementation Test; Golgi apparatus; growth and development; homeostasis; leaves; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; Molecular Sequence Data; Multigene Family; mutagenesis; Organ Specificity - drug effects; Organ Specificity - genetics; phylogenetic analysis; Phylogeny; plant growth; plant micronutrients; Plant Proteins - genetics; Plant Proteins - metabolism; RNA, Messenger - genetics; RNA, Messenger - metabolism; Saccharomyces cerevisiae - metabolism; site‐directed mutagenesis; Stress, Physiological - drug effects; Stress, Physiological - genetics; Subcellular Fractions - metabolism; transporters; Triticum - drug effects; Triticum - genetics; Triticum - metabolism; Triticum aestivum; virus‐induced gene silencing; wheat; yeasts; site-directed mutagenesis; Monocotyledones; Site directed mutagenesis; Plant ecology; Identification; Phylogeny; virus-induced gene silencing; Cereal crop; Golgi apparatus; Characterization; Virus; Gene silencing; phylogenetic analysis; Gramineae; Analysis; Angiospermae; Multigene family; Spermatophyta; Copper; Triticum aestivum
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.12263

Copper is an essential micronutrient for plant growth and development, and copper transporter plays a pivotal role for keeping copper homeostasis. However, little is known about copper transporters in wheat. Here, we report a novel copper transporter gene family, TaCT1, in common wheat. Three TaCT1 homoeologous genes were isolated and assigned to group 5 chromosomes. Each of the TaCT1 genes (TaCT1‐5A, −5B or −5D) possesses 12 transmembrane domains. TaCT1 genes exhibited higher transcript levels in leaf than in root, culm and spikelet. Excess copper down‐regulated the transcript levels of TaCT1 and copper deficiency‐induced TaCT1 expression. Subcellular experiments localized the TaCT1 to the Golgi apparatus. Yeast expression experiments and virus‐induced gene silencing analysis indicated that the TaCT1 functioned in copper transport. Site‐directed mutagenesis demonstrated that three amino acid residues, Met³⁵, Met³⁸ and Cys³⁶⁵, are required for TaCT1 function. Phylogenetic and functional analyses suggested that homologous genes shared high similarity with TaCT1 may exist exclusively in monocot plants. Our work reveals a novel wheat gene family encoding major facilitator superfamily (MFS)‐type copper transporters, and provides evidence for their functional involvement in promoting copper uptake and keeping copper homeostasis in common wheat.