Hypoxically inducible barley alanine aminotransferase: cDNA cloning and expression analysis

• Published in: Plant molecular biology Vol. 24; no. 3; pp. 417 - 427
• Main Authors: Muench, D.G. (Alberta Univ., Edmonton, Alta. (Canada). Dept. of Genetics), Good, A.G
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-02-1994
• Subjects: ADN; ALANINA AMINOTRANSFERASA; ALANINE AMINOTRANSFERASE; Alanine Transaminase - biosynthesis; Alanine Transaminase - genetics; Alanine Transaminase - isolation & purification; Amino Acid Sequence; Anaerobiosis; ANOXIA; ANOXIE; Base Sequence; Biological and medical sciences; Cell Hypoxia; Cloning, Molecular; DNA; DNA, Complementary - metabolism; Enzyme Induction; ESTRES; Fundamental and applied biological sciences. Psychology; Gene Expression; Hordeum - enzymology; Hordeum - genetics; HORDEUM VULGARE; Kinetics; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; NUCLEOTIDE SEQUENCE; Open Reading Frames; Plants - enzymology; Polymerase Chain Reaction; RACINE; RAICES; RNA, Messenger - biosynthesis; RNA, Messenger - metabolism; ROOTS; SECUENCIA NUCLEICA; Sequence Homology, Amino Acid; SEQUENCE NUCLEIQUE; Space life sciences; STRESS; Monocotyledones; Homology; Cereal crop; Regulation(control); Messenger RNA; Gramineae; Angiospermae; Molecular cloning; Aminoacid sequence; Hordeum vulgare; Weed; Root; Nucleotide sequence; Enzyme; Transferases; Sequence alignment; Panicum miliaceum; Tissue specificity; Plant leaf; Gene expression; Complementary DNA; Transaminases; Alanine transaminase; Spermatophyta; Comparative study
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1007/bf00024110

A 1.75 kb cDNA containing the entire coding sequence of the hypoxically inducible alanine aminotransferase (AlaAT) from barley roots was isolated and sequenced. This clone has an open reading frame of 1446 bp, and a deduced amino acid sequence of 482 residues, giving an estimated protein molecular mass of 52,885 Da. RNA blot analysis of barley root tissue showed a 4-fold increase of a single AlaAT-2 mRNA band after 12-24 hours of hypoxic stress, followed by a decrease in message levels after 48 h of hypoxic conditions. AlaAT-2 protein concentration increased in a similar pattern to AlaAT activity in root tissue, to almost 6-fold the aerobic level after 96 h of hypoxic stress. AlaAT-2 activity increased more than 2-fold in roots of Panicum miliaceum exposed to hypoxia, and is the same isoform as the light inducible AlaAT in P. miliaceum leaves. The unique expression patterns of AlaAT-2 in root and leaf tissue upon exposure to different environmental stimuli is also discussed.