Koizuka N, Tanaka Y, Morohashi Y. Isolation of a cDNA Clone for alpha-Amylase in Mung Bean Cotyledons : Analysis of alpha-Amylase mRNA Levels in Cotyledons during and following Germination of Mung Bean Seeds.
PLANT PHYSIOLOGY 1990;
94:1488-91. [PMID:
16667859 PMCID:
PMC1077404 DOI:
10.1104/pp.94.3.1488]
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Abstract
A cDNA was isolated that codes for alpha-amylase in mung bean (Vigna radiata) cotyledons, and the nucleotide sequence was determined. The deduced amino acid sequence (421 amino acid residues) is about 65% homologous with those of barley alpha-amylases. By comparing the deduced sequence with the sequence of the purified alpha-amylase, it was inferred that 23 N-terminal amino acids of a nascent polypeptide represent a signal peptide. Northern blot analysis showed that the levels of alpha-amylase mRNA are in parallel with the activities of alpha-amylase synthesis in cotyledons. Under the conditions where the solute leakage from cotyledons is accelerated during imbibition, a rapid increase in the amount of the alpha-amylase mRNA occurs. We postulate that a factor(s) which regulates in an inhibitory manner the alpha-amylase expression at the transcriptional level may be present in dry cotyledons and be removed by leakage.
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