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Abstracte soybean is relatively sensitive to disturbances arising from ooding before its emergence from the soil. When young soybean seedlings at an early stage are transferred to ooding anaerobic conditions, alcohol dehydrogenase (Adh) mRNA and Adh protein increase temporarily in the root tips, where active cell division demands high energy production. Since there is little information on the signi cance of the up-regulation of Adh for the tolerance of soybeans to ooding stress, we examined the response to ooding in transgenic soybean lines in which the soybean Adh (GmAdh2) gene was introduced under the control of a constitutive promoter. Acquired transgenic soybean seeds from one out of 14 transgenic lines were subjected to ooding stress. Growth inhibition of soybean seedlings caused by ooding stress was reduced in soybeans with the GmAdh2 transgene. Protein analysis and enzyme assay at the early stage of growth of the soybean seedlings con rmed that Adh expressions and activities in transgenic soybeans were increased compared to control soybeans. ese results indicated that the introduced GmAdh2 gene might have induced some change in glycolysis and alcohol fermentation, and improved the germination of transgenic soybeans under ooding stress. Key words:Alcohol dehydrogenase, ooding, soybean, transformation, transgenic soybean.Soybeans are generally intolerant of flooding stress. In many regions of Japan, soybean seeds are sown in a paddy eld during the summer-rainy season, and excess rainfall after sowing can often lead to soil flooding. Flooding a er sowing causes severely decreased crop yields. ese lower yields may result from the collapse of cotyledons due to rapid imbibitions of water (Nakayama et al. 2004) and from serious damage to the root system. Accordingly, it is important to understand the mechanism of the ooding stress responses in order to improve crop yields. However, the flooding stress responses in soybeans are not well characterized.Studies of the responses of soybean seedlings to flooding stress showed that flooding inhibits root elongation and hypocotyl pigmentation (Hashiguchi et al. 2009) and a ects the expression of some proteins involved in the processes of fermentation (Russell et al. 1990), the scavenging of reactive oxygen species (Shi et al. 2008), glycolysis, protein storage, and defense against disease (Hashiguchi et al. 2009). Since alcoholic fermentation is the major fermentation pathway of glycolysis in anaerobic plants (Rees et al. 1987;Komatsu et al. 2010a), the mechanism of tolerance to ooding stress should include the upregulation of genes engaged in glycolysis and alcohol fermentation. Under low oxygen stress conditions, plants activate alcohol fermentation in which pyruvate is used as a starting substrate. Pyruvate decarboxylase (Pdc, EC 4.1.1.1) catalyzes the rst step and converts pyruvate to acetaldehyde.en, alcohol dehydrogenase (Adh, EC 1.1.1.1) converts acetaldehyde to ethanol, with the concomitant regeneration of NAD + for glycolysis. Adh is a fermentative enzyme that...

A Gram-positive polychlorinated-biphenyl (PCB) degrader, Rhodococcus jostii RHA1, degrades PCBs by cometabolism with biphenyl. A two-component BphS1T1 system encoded by bphS1 and bphT1 (formerly bphS and bphT) is responsible for the transcription induction of the five gene clusters, bphAaAbAcAdC1B1, etbAa1Ab1CbphD1, etbAa2Ab2AcD2, etbAdbphB2, and etbD1, which constitute multiple enzyme systems for biphenyl/PCB degradation. The bphS2 and bphT2 genes, which encode BphS2 and BphT2, virtually identical to BphS1 (92%) and BphT1 (97%), respectively, were characterized. BphS2T2 induced the activation of the bphAa promoter in a host, Rhodococcus erythropolis IAM1399, in the presence of a variety of aromatics, including benzene, toluene, ethylbenzene, xylenes, isopropylbenzene, and chlorinated benzenes, as effectively as BphS1T1. The substrate spectrum of BphS2T2 was the same as that of BphS1T1, except for biphenyl, which is a substrate only for BphS1T1. BphS2T2 activated transcription from the five promoters of biphenyl/PCB degradation enzyme gene clusters as effectively as BphS1T1. The targeted disruptions of the bphS1, bphS2, bphT1, and bphT2 genes indicated that all these genes are involved in the growth of RHA1 on aromatic compounds. The hybrid system with bphS1 and bphT2 and that with bphS2 and bphT1 were constructed, and both systems conducted induced activation of the bphAa promoter, indicating cross-communication. These results indicated that RHA1 employs not only multiple enzyme systems, but also dual regulatory systems for biphenyl/PCB degradation. Comparison of the sequences, including bphS2T2, with the bphS1T1-containing sequences and the corresponding sequences in other rhodococcal degraders suggests that bphS2T2 might have originated from bphS1T1.

Agrobacterium tumefaciens KAT23 isolated from peach root causes crown gall disease in a number of grain legume plants, including the common bean (Phaseolus vulgaris) and soybean (Glycine max). KAT23 caused tumor formation in each of these plants more effectively than strain C58. Biotype determination suggested that this strain is biotype II. KAT23 was able to utilize nopaline as a carbon source. Partial sequence analysis indicated that KAT23 harbors a nopaline-type Ti plasmid, designated pTiKAT23, which was highly homologous with other nopaline-type Ti plasmids (pTiC58 and pTiSAKURA). KAT23 transferred not only the T-DNA of the Ti plasmid but also introduced T-DNA of the binary vector efficiently. The common bean inoculated with KAT23 (pIGFP121-Hm) showed crown galls, and some plants showed beta-glucuronidase (GUS) and sGFP (S65T) gene expression. This virulent ability of KAT23 indicates its potential application to legumes, especially to soybean transformation.