Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 1.37

ANALYSIS OF THE ROLE OF C4-3, A TOBACCO GENE EXPRESSED DURING FLOWER GROWTH, IN THE DEVELOPMENT OF ANTHERS

V. CECCHETTI*, M. POMPONI*, S. D'ANGELI*, M.M. ALTAMURA*, G.B. TORNIELLI**, M. PEZZOTTI***, P. COSTANTINO*, M. CARDARELLI***

*) Università La Sapienza Roma

**) Università degli Studi Verona

***) CNR Roma

auxin, rolB, anther development, C4-3

Auxin has a substantial role in floral organ development. We demonstrated an effect of auxin in the process of anther development and dehiscence by means of the localised expression of the Agrobacterium rhizogenes rolB oncogene that induces a cell-autonomous state of auxin hypersensitivity. Tobacco pDMC1:rolB plants, that express the rolB oncogene under the control of the meiosis specific promoter AtDMC1, are male sterile due to alterations in meiosis causing a reduced number of pollen grains as well as a severe delay in anther dehiscence that causes pollen release when the stigma is no longer receptive to impollination. Moreover these plants display reduced stamen growth due to shorter filaments as compared to controls. Real-time RT-PCR analysis of mRNA extracted from male sterile pDMC1:rolB anthers, at meiotic and posmeiotic stages, shows an increase in the transcript level of C4-3, a c-DNA overexpressed in tobacco protoplasts expressing rolB. Remarkably, tobacco plants transformed with an antisense C4-3 c-DNA under the control of the CaMV35S promoter show an increase in stamen lenght, suggesting a role for C4-3 in filament elongation.