The Arabidopsis SUCROSE UNCOUPLED-6 gene is identical to ABSCISIC ACID INSENSITIVE-4 : involvement of abscisic acid in sugar responses.
Huijser, Casper 1 2 *; Kortstee, Anne 1 2; Pego, Jonatas 1 2 +; Weisbeek, Peter 2; Wisman, Ellen 3 ++; Smeekens, Sjef 1
[Article] Plant Journal. 23(5):577-585, September 2000.

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Summary: In plants, sugars act as signalling molecules that control many aspects of metabolism and development. Arabidopsis plants homozygous for the recessive sucrose uncoupled-6 (sun6) mutation show a reduced sensitivity to sugars for processes such as photosynthesis, gene expression and germination. The sun6 mutant is insensitive to sugars that are substrates for hexokinase, suggesting that SUN6 might play a role in hexokinase-dependent sugar responses. The SUN6 gene was cloned by transposon tagging and analysis showed it to be identical to the previously described ABSCISIC ACID INSENSITIVE-4 (ABI4) gene. Our analysis suggests the involvement of abscisic acid and components of the abscisic acid signal transduction cascade in a hexokinase-dependent sugar response pathway. During the plant life cycle, SUN6/ABI4 may be involved in controlling metabolite availability in an abscisic acid- and sugar-dependent way.

(C) 2000 Blackwell Science Ltd.