title: Isolation and expression features of hexose kinase genes under various abiotic stresses in the tea plant (Camellia sinensis).
abstract: Hexokinases (HXKs, EC 2.7.1.1) and fructokinases (FRKs, EC 2.7.1.4) play important roles in carbohydrate metabolism and sugar signaling during the growth and development of plants. However, the HXKs and FRKs in the tea plant (Camellia sinensis) remain largely unknown. In this manuscript, we present the molecular characterization, phylogenetic relationships, conserved domains and expression profiles of four HXK and seven FRK genes of the tea plant. The 11 deduced CsHXK and CsFRK proteins were grouped into six main classes. All of the deduced proteins, except for CsFKR7, possessed putative ATP-binding motifs and a sugar recognition region. These genes exhibited tissue-specific expression patterns, which suggests that they play different roles in the metabolism and development of source and sink tissues in the tea plant. There were variations in CsHXKs and CsFRKs transcript abundance in response to four abiotic stresses: cold, salt, drought and exogenous abscisic acid (ABA). Remarkably, CsHXK3 and CsHXK4 were significantly induced in the leaves and roots under cold conditions, CsHXK1 was apparently up-regulated in the leaves and roots under salt and drought stresses, and CsHXK3 was obviously stimulated in the leaves and roots under short-term treatment with exogenous ABA. These findings demonstrate that CsHXKs play critical roles in response to abiotic stresses in the tea plant. Our research provides a fundamental understanding of the CsHXK and CsFRK genes of the tea plant and important information for the breeding of stress-tolerant tea cultivars.
authors.affiliation: National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Na-Na
authors.initials: NN
authors.lastname: Li
authors.affiliation: National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; College of Horticulture, Northwest Agriculture and Forestry University, Yangling 712100, China.
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Qian
authors.affiliation: National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.affiliation: National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Cao
authors.affiliation: National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China.
authors.forename: Xin-Yuan
authors.initials: XY
authors.lastname: Hao
authors.affiliation: National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China. Electronic address: yjyang@tricaas.com.
authors.forename: Ya-Jun
authors.initials: YJ
authors.lastname: Yang
authors.affiliation: National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Hangzhou 310008, China. Electronic address: xcw75@tricaas.com.
authors.forename: Xin-Chao
authors.initials: XC
authors.lastname: Wang
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D028241:Camellia sinensis / Q000201:enzymology* / Q000235:genetics* / Q000502:physiology; D017124:Conserved Sequence; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D009928:Organ Specificity / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics*
chemical_list: D010940:Plant Proteins
keywords: Abiotic stress; Fructokinase; Gene expression; Hexokinase; Tea plant