Vázquez-Santana, Sonia , Orozco-Arroyo, Gregorio , Flores-Renteria, Lluvia , Montero-Alfaro, Odeth , Alfaro-Pereira, Isabel , Márquez-Guzmán, Judith , Cruz-García, Felipe .
Carpel development genes and dioecy in the cactus Opuntia stenopetala.
Opuntia stenopetala is a member of the Cactaceae family and is a dioecious species with separated male and female individuals. In this species, sexual organ differentiation is initiated in both male and female flowers but it is not concluded. The functionally male flowers present a phenotype without stigma, incomplete ovule development, and in some cases, the ovary cavity is empty or absent. In female flowers only one phenotype is observed, plants present male sterility, which is related with pollen abortion, since microspores do not complete meiosis, instead of, they undergo programmed cell death. Genetics and molecular processes that led to dioecy are poorly understood. As a first approach, we are studying, genes that could be associated to the male phenotype of O. stenopetala. We looked for pistil mutants in Arabidopsis thaliana, in particular those with a stigmaless phenotype, since in O. stenopetala this defect is constant in the male flowers of a wild population. We found at least three mutants with a stigmaless phenotype in A. thaliana. Genes affected in these mutants are STYLISH (STY), CRABS CLAW (CRC) and TOUSLED (TSL). STY encodes a protein with a putative zinc-binding RING-finger-like domain and it is required for stylar and stigmatic tissue development. CRC encodes a member of YABBY family and it has been thought as a transcription factor that regulates carpel development. TSL encodes a nuclear localized serine/threonine protein kinase. The tsl mutants show an unfused gynoecium in their apical parts and develop reduced amounts of stylar and stigmatic tissues, indicating that TSL promotes the formation and fusion of these tissues. We have cloned from O. stenopetala partial cDNAs, which are orhologs of STY, CRC and TSL. Expression analysis by Northern-blot and RT-PCR shows that neither OsSTY nor OsCRC has expression differences in styles nor anthers from female or male flowers. However, when we analyzed OsTSL expression, we found that this gene is overexpressed in styles from male flowers. Data are discussed in the framework of dioecious evolution. DGAPA IN21610; PAIP 629015
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1 - Universidad Nacional Autónoma de México, Biología Comparada, Facultad de Ciencias, Ciudad Universitaria, Mexico, DF, 04510, México
2 - Universidad Nacional Autónoma de México, Bioquimica
3 - Universidad Nacional Autónoma de México, Biología Comparada
O. stenopetala unisexuallity
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM