Interallelic complementation at the Arabidopsis CRE1 locus uncovers independent pathways for the proliferation of vascular initials and canonical cytokinin signalling
Por:
García-Ponce De Léon B., Franco Zorrilla J.M., Rubio V., Dahiya P., Paz-Ares J., Leyva A.
Publicada:
1 ene 2004
Resumen:
The differentiation of vascular tissue plays a central role in root architecture and its functionality. Regardless of its importance, the molecular mechanisms involved in the inception of vascular morphogenesis and their interaction with hormones are only now beginning to be understood. The characterisation of the WOODEN LEG (wol/cre1 mutant), impaired in procambial cell proliferation and the identification of WOL/CRE1 as a cytokinin receptor, provided the first genetic evidence pointing to a role of cytokinins in the formation of vascular initials. However, the striking wol phenotype in vascular differentiation is unique among all the available cre7 alleles collection. In this work, we identified a mutant with identical deficiencies in vascular differentiation as wol. Complementation analysis revealed that this mutant rescued the wol short-root phenotype. However, genetic characterisation of the mutant showed that the mutation was located at the CRE1 locus, indicating that both alleles displayed interallelic complementation. Trans-heterozygotes characterisation showed that these plants fully restored the deficiency in vascular differentiation but not the canonical cytokinin signalling. Furthermore, we show that, as measured in root growth inhibition, calli regeneration assays and northern analysis, the original wol allele is in fact more sensitive to cytokinins than the transheterozygous plants, or some cre1 alleles showing wild-type vascular morphogenesis. Thus, there is no strict correlation between the phenotype in vascular differentiation displayed by the cre1/wol alleles and canonical cytokinin signalling. These results indicate that at least partially independent regulatory circuits may operate in procambial cell proliferation and in cytokinin responsiveness exerted through the CRE1 receptor.
Filiaciones:
García-Ponce De Léon B.:
Depto. de Genet. Molec. de Plantas, Ctro. Nac. de Biotecnología, Camp. Univ. Auton. Madrid C., 28049 Madrid, Spain
Instituto de Biotzecnología, UNAM, Av Universidad 2001, Cuernavaca Morelos, Mexico
Franco Zorrilla J.M.:
Depto. de Genet. Molec. de Plantas, Ctro. Nac. de Biotecnología, Camp. Univ. Auton. Madrid C., 28049 Madrid, Spain
Rubio V.:
Depto. de Genet. Molec. de Plantas, Ctro. Nac. de Biotecnología, Camp. Univ. Auton. Madrid C., 28049 Madrid, Spain
Dept. Molec., Cell. Devmtl. Biol., Yale University, New Haven, CT 06520-8104, United States
Dahiya P.:
Dept. of Cell and Devmtl. Biology, John Innes Center, Colney Lane, Norwich NR4 7UH, United Kingdom
Paz-Ares J.:
Depto. de Genet. Molec. de Plantas, Ctro. Nac. de Biotecnología, Camp. Univ. Auton. Madrid C., 28049 Madrid, Spain
Leyva A.:
Depto. de Genet. Molec. de Plantas, Ctro. Nac. de Biotecnología, Camp. Univ. Auton. Madrid C., 28049 Madrid, Spain
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