© 2007 Heron Publishing—Victoria, Canada
Two SCARECROW-LIKE genes are induced in response to exogenous auxin in rooting-competent cuttings of distantly related forest species
Conchi Sánchez (1), Jesús M. Vielba (1), Enrique Ferro (1), Guillermo Covelo (2), Alicia Solé (3), Dolores Abarca (3), Belén S. de Mier (3) and Carmen Díaz-Sala (3, 4)
1. Department of Plant Physiology, Instituto de Investigaciones Agrobiológicas de Galicia (CSIC), Apartado 122, 15080, Santiago
de Compostela, Spain / 2. Department of Biochemistry and Molecular Biology, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain / 3. Department of Plant Biology, University of Alcalá, 28871 Alcalá de Henares, Madrid, Spain / 4. Corresponding author (carmen.diazsala@uah.es) / Received August 31, 2006; accepted January 12, 2007; published online July 3, 2007
Summary
We characterized SCARECROW-LIKE genes induced by auxin in rooting-competent cuttings of two distantly related forest species (Pinus radiata D. Don and Castanea sativa Mill.) before the activation of cell division that results in adventitious root formation. The predicted protein sequences
contain domains characteristic of the GRAS protein family and show a strong similarity to the SCARECROW-LIKE proteins, indicating conserved functions of these proteins. Quantitative RT-PCR analysis showed that these genes are expressed
at relatively high levels in roots. Induction of increased mRNA levels in rooting-competent cuttings of both species in response
to exogenous auxin was observed within the first 24 h of the root induction process, a time when cell reorganization takes
place, but before the resumption of cell division and the appearance of adventitious root primordia. These results suggest
that SCARECROW-LIKE genes play a role during the earliest stages of adventitious root formation.
Keywords:
chestnut, pine, root meristem, vegetative propagation.
