An AGAMOUS-related MADS-box gene, XAL1 (AGL12), regulates root meristem cell proliferation and flowering transition in Arabidopsis
Por:
Tapia-López R., García-Ponce B., Dubrovsky J.G., Garay-Arroyo A., Pérez-Ruíz R.V., Kim, SH, Acevedo F., Pelaz S., Alvarez-Buylla E.R.
Publicada:
1 mar 2008
Resumen:
MADS-box genes are key components of the networks that control the transition to flowering and flower development, but their role in vegetative development is poorly understood. This article shows that the sister gene of the AGAMOUS (AG) clade, AGL12, has an important role in root development as well as in flowering transition. We isolated three mutant alleles for AGL12, which is renamed here as XAANTAL1 (XAL1): Two alleles, xal1-1 and xal1-2, are in Columbia ecotype and xal1-3 is in Landsberg erecta ecotype. All alleles have a short-root phenotype with a smaller meristem, lower rate of cell production, and abnormal root apical meristem organization. Interestingly, we also encountered a significantly longer cell cycle in the strongest xal1 alleles with respect to wild-type plants. Expression analyses confirmed the presence of XAL1 transcripts in roots, particularly in the phloem. Moreover, XAL1Tb-glucuronidase expression was specifically up-regulated by auxins in this tissue. In addition, mRNA in situ hybridization showed that XAL1 transcripts were also found in leaves and floral meristems of wildtype plants. This expression correlates with the late-flowering phenotypes of the xal1 mutants grown under long days. Transcript expression analysis suggests that XAL1 is an upstream regulator of SOC, FLOWERING LOCUS T, and LFY. We propose that XAL1 may have similar roles in both root and aerial meristems that could explain the xal1 late-flowering phenotype. © 2008 American Society of Plant Biologists.
Filiaciones:
Univ Nacl Autonoma Mexico, Inst Ecol, Genet Mol Lab, Mexico City 04510, DF, Mexico
Univ Nacl Autonoma Mexico, Inst Biotecnol, Dept Biol Mol Plantas, Cuernavaca 62191, Morelos, Mexico
ICREA and LGMV, IBMB-CSIC C, 08034 Barcelona, Spain
All Open Access, Hybrid Gold
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