Abstract
Glycinebetaine (betaine) highly accumulates as a compatible solute in many chenopods and has been considered to play a role in the protection from salt stress. The betaine biosynthesis pathway involves betainealdehyde dehydrogenase, choline monooxygenase, phosphoethanolamine N-methyltransferase, S-adenosyl-L-methionine synthetase. We examined the transcriptional regulation patterns of these genes in chenopods. The patterns of these genes in the leaves highly resembled each others in halophyte Atriplex nummularia and leaf beet (Beta vulgaris). However, the regulation patterns of these genes did not so resembled each others in spinach (Spinacia oleracea), which is more sensitive to salt stress than the above two plants. A. nummularia and leaf beet may have a system for regulating the expression of the enzymes in order to maintain specific pool sizes of metabolic intermediates in the leaves. The details of the gene expressions will be presented.
