title: Identification and expression analyses of the alanine aminotransferase (AlaAT) gene family in poplar seedlings.
abstract: Alanine aminotransferase (AlaAT, E.C.2.6.1.2) catalyzes the reversible conversion of pyruvate and glutamate to alanine and α-oxoglutarate. The AlaAT gene family has been well studied in some herbaceous plants, but has not been well characterized in woody plants. In this study, we identified four alanine aminotransferase homologues in Populus trichocarpa, which could be classified into two subgroups, A and B. AlaAT3 and AlaAT4 in subgroup A encode AlaAT, while AlaAT1 and AlaAT2 in subgroup B encode glutamate:glyoxylate aminotransferase (GGAT), which catalyzes the reaction of glutamate and glyoxylate to α-oxoglutarate and glycine. Four AlaAT genes were cloned from P. simonii × P. nigra. PnAlaAT1 and PnAlaAT2 were expressed predominantly in leaves and induced by exogenous nitrogen and exhibited a diurnal fluctuation in leaves, but was inhibited in roots. PnAlaAT3 and PnAlaAT4 were mainly expressed in roots, stems and leaves, and was induced by exogenous nitrogen. The expression of PnAlaAT3 gene could be regulated by glutamine or its related metabolites in roots. Our results suggest that PnAlaAT3 gene may play an important role in nitrogen metabolism and is regulated by glutamine or its related metabolites in the roots of P. simonii × P. nigra.
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), School of Forestry, Northeast Forestry University, Harbin 150040, China.|College of Life Science, Northeast Forestry University, Harbin 150040, China.
authors.forename: Zhiru
authors.initials: Z
authors.lastname: Xu
authors.affiliation: College of Life Science, Northeast Forestry University, Harbin 150040, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), School of Forestry, Northeast Forestry University, Harbin 150040, China.|School of Forestry, Northeast Forestry University, Harbin 150040, China.
authors.forename: Chunpu
authors.initials: C
authors.lastname: Qu
authors.affiliation: College of Life Science, Northeast Forestry University, Harbin 150040, China.
authors.forename: Yanbo
authors.initials: Y
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), School of Forestry, Northeast Forestry University, Harbin 150040, China.
authors.forename: Bingqing
authors.initials: B
authors.lastname: Hao
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), School of Forestry, Northeast Forestry University, Harbin 150040, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), School of Forestry, Northeast Forestry University, Harbin 150040, China.
authors.forename: Zhongye
authors.initials: Z
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), School of Forestry, Northeast Forestry University, Harbin 150040, China.
authors.forename: Han
authors.initials: H
authors.lastname: Yang
authors.affiliation: School of Forestry, Northeast Forestry University, Harbin 150040, China.
authors.forename: Chengjun
authors.initials: C
authors.lastname: Yang
authors.affiliation: College of Life Science, Northeast Forestry University, Harbin 150040, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Saline-alkali Vegetation Ecology Restoration in Oil Field (SAVER), Ministry of education, Alkali Soil Natural Environmental Science Center (ASNESC), Northeast Forestry University, Harbin 150040, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding (Northeast Forestry University), School of Forestry, Northeast Forestry University, Harbin 150040, China.|School of Forestry, Northeast Forestry University, Harbin 150040, China.
authors.forename: Guanjun
authors.initials: G
authors.lastname: Liu
mesh_terms: D000410:Alanine Transaminase / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005973:Glutamine / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D005810:Multigene Family; D009584:Nitrogen / Q000378:metabolism; D010802:Phylogeny; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics; D018547:Plant Stems / Q000201:enzymology / Q000235:genetics; D032107:Populus / Q000201:enzymology / Q000235:genetics*; D036226:Seedlings / Q000201:enzymology / Q000235:genetics*
chemical_list: D007527:Isoenzymes; D010940:Plant Proteins; D005973:Glutamine; D000410:Alanine Transaminase; D009584:Nitrogen