Submergence-Induced ADH and ALDH Gene Expression in Japonica and Indica Rice with Contrasting Levels of Seedling Vigor under Submergence Stress

Abstract

ABSTRACTADH and ALDH gene expression was studied by reverse transcriptase polymerase chain reaction (RT-PCR) using selected indica and japonica rice cultivars showing vigorous and non-vigorous post-germination seedling growth under submergence stress. Transcript amount of ADH1, ADH2 and ALDH2a increased dramatically under submergence irrespective of dark/light conditions in both indica and japonica rice, whereas ALDH2b gene expression was greatly suppressed. Submergence-induced increases of the transcript levels also occurred in floating rice as well as in selected chromosome segment substitution lines that were derived from crosses between ‘Nipponbare’ and ‘Kasalath’. However, no cultivar and line differences were observed in their transcript levels under submergence. Our results suggest that the expression of ADH1, ADH2 and ALDH2a genes is highly responsive to submergence stress but is not a major determinant of the cultivar/genotype-specific level of seedling vigor under submergence.