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The CRABS CLAW ortholog from California poppy ( Eschscholzia californica, Papaveraceae) , EcCRC , is involved in floral meristem termination, gynoecium differentiation and ovule initiation
Author(s) -
Orashakova Svetlana,
Lange Matthias,
Lange Sabrina,
Wege Stefanie,
Becker Annette
Publication year - 2009
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2009.03807.x
Subject(s) - biology , gynoecium , ovule , meristem , agamous , genetics , arabidopsis , homeotic gene , gene , botany , phenotype , mutant , stamen , embryo , pollen
Summary The Arabidopsis transcription factor CRABS CLAW ( CRC ) is a major determinant of carpel growth and fusion, and, in concert with other redundantly acting genes, of floral meristem termination. Its rice ortholog, however, has additional functions in specifying carpel organ identity. We were interested in understanding the history of gene function modulation of CRC ‐like genes during angiosperm evolution. Here, we report the identification and functional characterization of EcCRC , the Californica poppy ( Eschscholzia californica ) CRC ortholog. The downregulation of EcCRC by virus‐induced gene silencing (VIGS) produces additional organ whorls that develop exclusively into gynoecia, resulting in a reiteration of the fourth whorl. Additionally, defects in carpel polarity and ovule initiation are apparent, and the observed phenotype is restricted to the gynoecium. Our results further show that the history of CRC ‐like genes during angiosperm evolution is characterized by gains of function, independent of duplication processes in this gene subfamily. Moreover, our data indicate that the ancestral angiosperm CRC ‐like gene was involved in floral meristem termination and the promotion of abaxial cell fate in the gynoecium, and that in the lineage leading to Arabidopsis, additional genes have been recruited to adopt some of these functions, resulting in a high degree of redundancy.