Thawda Myint^1,, Sigit Ismawanto¹, Parameswari Namasivayam¹, Suhaimi Napis¹, Mohd Puad Abdulla¹

In plants, ethanolic fermentation occurs during limited oxygen condition and under certain environmental stresses. Many of the observations reported on the ADH1 gene during environmental stress conditions were obtained from studies that used single isoforms of the gene ADH1 even though many isoforms of the genes are known to be operational in plants based the complete genome sequence of more than 20 different plant species. Here, the Arabidopsis plants were exposed to polyethylene glycol-induced drought stress and the whole set of ADH (EC.1.1.1.1) genes as well as the enzyme activity of ADH in response to PEG-induced water stress condition was presented and discussed. At enzyme levels, both the root and leaf NADH-ADH activities were increased 5.9 and 4.4 folds when treated with 5% (w/v) PEG-20,000. At gene level, the majority of the ADH1 gene AT1G77120 and two of the ADH-like genes (AT1G64710 and AT5G24760) were up-regulated in the leaf and root. The result suggests that ADH1 together with other two more ADH-likes genes were responsive in the leaf and root operating along side during the PEG-induced water stress and these evidences support the conclusion that the capacity of ethanolic fermentation was enhanced in response to drought.

Arabidopsis, PEG induced water stress, RWC, proline, chlorophyll, alcohol dehydrogenase