The SE7 somaclonal line of finger millet (Eleusine coracana) achieved increased grain yield in field trials that apparently resulted from a higher number of inflorescences and seeds per plant, compared with the wild type. Levels of endogenous cytokinins, especially those of highly physiologically active iso-pentenyl adenine, were increased during early inflorescence development in SE7 plants. Transcript levels of cytokinin-degrading enzymes but not of a cytokinin-synthesizing enzyme were also decreased in young leaves, seedlings, and initiating inflorescences of SE7. These data suggest that attenuated degradation of cytokinins in SE7 inflorescences leads to higher cytokinin levels that stimulate meristem activity and result in production of more inflorescences. Gene expression was compared between SE7 and wild-type young inflorescences using the barley 12K cDNA array. The largest fraction of up-regulated genes in SE7 was related to transcription, translation, and cell proliferation, cell wall assembly/biosynthesis, and to growth regulation of young and meristematic tissues including floral formation. Other up-regulated genes were associated with protein and lipid degradation and mitochondrial energy production. Down-regulated genes were related to pathogen defence and stress response, primary metabolism, glycolysis, and the C:N balance. The results indicate a prolonged proliferation phase in SE7 young inflorescences characterized by up-regulated protein synthesis, cytokinesis, floral formation, and energy production. In contrast, wild-type inflorescences are similar to a more differentiated status characterized by regulated protein degradation, cell elongation, and defence/stress responses. It is concluded that attenuated degradation of cytokinins in SE7 inflorescences leads to higher cytokinin levels, which stimulate meristem activity, inflorescence formation, and seed set.

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Transgenic apple (Malus · domestica Borkh.) 'Florina' plants were obtained by Agrobacterium-mediated transformation. The efficiency of gene transfer was 7.9%, calculated as a number of explants producing at least one transgenic shoot, after co-cultivation of leaf explants from in vitro-grown shoots in a thin layer of the A. tumefaciens C58C1 strain with the binary vector pCMB-B:GUS. Polymerase chain reaction revealed that all the clones contained the nptII and rolB genes, while four of them did not contain the gus gene. Southern blot analysis confirmed the integration of the nptII and rolB genes, with one to three copies per genome being present. All independent rolB-transgenic lines were able to produce roots in vitro on the hormone free medium, while the plants, transformed with the vector pIB16.1, or untransformed control plants did not root, and only half of shoots of MM106 rootstock rooted on this medium. The average root number in the rolB-transgenic clones ranged from 4 to 7.7. Pretreatment with indole-3-butyric acid caused root formation in all transgenic and control plants and significantly increased root number in the rolBtransgenic lines, compared to untransformed plants. RolB-transgenic plants, grown in vivo in greenhouse for 2 years, did not differ phenotypically from the wild type line with the exception of root parts. All rolBtransformed plants produced altered root systems containing more fine roots leading to significantly increased fresh root weight in five plant lines.Abbreviations: BA -6-benzyladenine; bp -base pair; gus -b-glucuronidase gene; IBA -indole-3-butyric acid; LB medium -Luria-Bertani medium; nptII -neomycin phosphotransferase; pat -phosphinothricin acetyltransferase