The establishment and maintenance of auxin maxima in vascular plants is regulated by auxin biosynthesis and polar intercellular auxin flow. The disruption of normal auxin biosynthesis in mouse-ear cress (Arabidopsis thaliana) leads to severe abnormalities, suggesting that spatiotemporal regulation of auxin biosynthesis is fundamental for normal growth and development. We have shown previously that the induction of the SHORT-INTERNODES/STYLISH (SHI/STY) family member STY1 results in increased transcript levels of the YUCCA (YUC) family member YUC4 and also higher auxin levels and auxin biosynthesis rates in Arabidopsis seedlings. We have also shown previously that SHI/STY family members redundantly affect development of flowers and leaves. Here, we further examine the function of STY1 by analyzing its DNA and protein binding properties. Our results suggest that STY1, and most likely other SHI/STY members, are DNA binding transcriptional activators that target genes encoding proteins mediating auxin biosynthesis. This suggests that the SHI/STY family members are essential regulators of auxin-mediated leaf and flower development. Furthermore, the lack of a shoot apical meristem in seedlings carrying a fusion construct between STY1 and a repressor domain, SRDX, suggests that STY1, and other SHI/STY members, has a role in the formation and/or maintenance of the shoot apical meristem, possibly by regulating auxin levels in the embryo.

Background-Cytosolic aldehyde dehydrogenase, or ALDH1A1, functions in ethanol detoxification, metabolism of neurotransmitters, and synthesis of retinoic acid. Because the promoter region of a gene can influence gene expression, the ALDH1A1 promoter regions were studied to identify polymorphism, to assess their functional significance, and to determine whether they were associated with a risk for developing alcoholism.

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were C. J. Peter Eriksson and Tatsushige Fukunaga. The presentations were (1) 4-Methylpyrazole as a tool in the investigation of the role of ADH in the actions of alcohol in humans, by Taisto Sarkola and C. J. Peter Eriksson; (2) ADH2 polymorphism and flushing in Asian populations, by Wei (6) ADH genotypes and alcohol use in Europeans, by John B. Whitfield.T HE BULK OF human alcohol metabolism takes place in the liver, where alcohol is first oxidized by alcohol dehydrogenase (ADH) to acetaldehyde, which is then oxidized by aldehyde dehydrogenase (ALDH) to acetate. All alcohol effects primarily can be derived from alcohol per se and/or its metabolism, including redox changes and the production of acetaldehyde and acetate. The rate of alcohol oxidation is the crucial factor that determines the metabolic consequences during alcohol intoxication. The hepatic NADH reoxidation together with the functional ADH and ALDH activities regulate the steady-state alcohol oxidation rate. Thus, any genetic polymorphism that affects functional ADH and ALDH activities may be relevant for the biological actions of alcohol.The first gene shown to affect the biological actions of alcohol was ALDH2. Deficiency of the ALDH2 enzyme, common in Asian populations, follows the pattern of a classical inborn error of metabolism, with dominant inheritance and high penetrance of the phenotype, which involves facial flushing due to blood vessel vasodilation, tachycardia, nausea, and headache in response to alcohol intake. These reactions, caused by inhibited acetaldehyde metabolism and subsequently elevated acetaldehyde levels, make alcohol drinking less pleasant and protect the individual from high consumption and alcoholism. Virtually no case of alcoholism has been reported in those individuals (about 5% to 10% of the entire Asian population) who are homozygous for the genotype (ALDH2*2/ *2). The heterozygous individuals with one *2-allele (30% to 40% of the entire Asian population) can drink but develop a number of side effects that include flushing. Within these individuals, the average alcohol consumption is less than in the *1/*1 population, but still alcoholism may develop.The relevance of the ADH system for the actions of alcohol is less well known than is the case with ALDH. Although seven ADH genes have been mapped to chromosome 4 in humans, relevant polymorphism has been found only for ADH2 and ADH3 (Smith, 1986). The kinetic differences among ADH2 isozymes are much more striking than those among the ADH3 isozymes. For example, the maximum rate of reaction (V max ) of ␤ 2 (encoded by ADH2*2) homodimers is around 40 times that of ␤ 1 (encoded by ADH2*1) homodimers, whereas the V max of ␥ 1