0172169 - UEB-Q 20013048 RIV US eng J - Journal Article
Werner, T. - Motyka, Václav - Strnad, Miroslav - Schmülling, T.
Regulation of plant growth by cytokinin.
Proceedings of the National Academy of Sciences of the United States of America. Roč. 98, č. 18 (2001), s. 10487-10492. ISSN 0027-8424. E-ISSN 1091-6490
R&D Projects: GA ČR GA522/00/1346
Institutional research plan: CEZ:AV0Z5038910
Keywords : Cytokinin * regulation of plant growth
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 10.890, year: 2001

Cytokinins are a cass of plant-specific hormones that play a central role during the cell cycle and influence numerous developmental programs. Because of the lack of biosynthetic and signaling mutants, the regulatory roles of cytokinins are not well understood. We genetically engineered cytokinin oxidase expression in transgenic tobacco plants to reduce their endogenous cytokinin content. Cytokinin-deficient plants developed stunted shoots with smaller apical meristems. The plastochrone was prolonged, and leaf cell production was only 3-4% that of wild type, indicating an absolute requirement of cytokinins for leaf growth. In contrast, root meristems of transgenic plants esere enlarged and gave rise to faster growing and more branched roots. These results suggest that cytokinins are an important regulatory factor of plant meristem activity and morphogenesis, with opposing roles in shoots and roots.
Permanent Link: http://hdl.handle.net/11104/0069211