Čeština
EnglishOver-expression of a zeatin O-glucosylation gene in maize leads to growth retardation and tasselseed formation.
Rodo AP, Brugiere N., Vankova R., Malbeck J., Olson J.M., Haines S.C., Martin R.C., Habben J.E., Mok D.W.S., Mok M.C.
JOURNAL OF EXPERIMENTAL BOTANY 59:: 2673-2686, 2008
Keywords: cytokinin, Zea mays, corn, zeatin O-glucosyltransferase, tasselseed, plant development
Abstract: To study the effects of cytokinin O-glucosylation in monocots, maize (Zea mays) transformants harboring the ZOG1 gene (encoding a zeatin O-glucosyltransferase from Phaseolus lunatus) under the control of the constitutive ubiquitin (Ubi) promoter were generated. The roots and leaves of the transformants had highly increased levels of zeatin-O-glucoside. The vegetative characteristics of hemizygous and homozygous Ubi:ZOG1 plants resembled those of cytokinin deficiency, including shorter stature, thinner stems, narrower leaves, smaller meristems, and increased root mass and branching. Transformant leaves had higher chlorophyll content than non-transformed sibs and also higher levels of active cytokinins. Senescence was delayed when plants were grown in the spring/summer. Modifications of the reproductive phase were unexpected. While hemizygous transformants had reduced tassels with fewer spikelets but normal viable pollen, homozygotes had very small tassels and feminized tassel florets, resembling tasselseed phenotypes. This novel finding demonstrates a link between cytokinins and sex-specific floral development in monocots.
DOI:
IEB authors: Radomíra Vaňková
JOURNAL OF EXPERIMENTAL BOTANY 59:: 2673-2686, 2008
Keywords: cytokinin, Zea mays, corn, zeatin O-glucosyltransferase, tasselseed, plant development
Abstract: To study the effects of cytokinin O-glucosylation in monocots, maize (Zea mays) transformants harboring the ZOG1 gene (encoding a zeatin O-glucosyltransferase from Phaseolus lunatus) under the control of the constitutive ubiquitin (Ubi) promoter were generated. The roots and leaves of the transformants had highly increased levels of zeatin-O-glucoside. The vegetative characteristics of hemizygous and homozygous Ubi:ZOG1 plants resembled those of cytokinin deficiency, including shorter stature, thinner stems, narrower leaves, smaller meristems, and increased root mass and branching. Transformant leaves had higher chlorophyll content than non-transformed sibs and also higher levels of active cytokinins. Senescence was delayed when plants were grown in the spring/summer. Modifications of the reproductive phase were unexpected. While hemizygous transformants had reduced tassels with fewer spikelets but normal viable pollen, homozygotes had very small tassels and feminized tassel florets, resembling tasselseed phenotypes. This novel finding demonstrates a link between cytokinins and sex-specific floral development in monocots.
DOI: