Journal article

Publication year: 2013

Pages: 289-301

Journal: Development Genes and Evolution

Volume number: 223

Issue number: 5

ISSN: 0949-944X

eISSN: 1432-041X

DOI Link: https://doi.org/10.1007/s00427-013-0446-8

Publisher: Springer

Abstract: 
In angiosperms, the shoot apical meristem is at the origin of leaves and
stems and is eventually transformed into the floral meristem. Class I knotted-like homeobox (KNOX I) genes are known as crucial regulators of shoot meristem formation and maintenance. KNOX I genes maintain the undifferentiated state of the apical meristem and are locally downregulated upon leaf initiation. In Arabidopsis, KNOX I genes, especially SHOOTMERISTEMLESS (STM), have been shown to regulate flower development and the formation of carpels. We investigated the role of STM-like genes in the reproductive development of Eschscholzia californica, to learn more about the evolution of KNOX I gene function in basal eudicots. We identified two orthologs of STM in Eschscholzia, EcSTM1 and EcSTM2, which are predominantly expressed in floral tissues. In contrast, a KNAT1/BP-like and a KNAT2/6-like KNOX I
gene are mainly expressed in vegetative organs. Virus-induced gene
silencing (VIGS) was used to knockdown gene expression, revealing that
both EcSTM genes are required for the formation of reproductive organs. Silencing of EcSTM1 resulted in the loss of the gynoecium and a reduced number of stamens. EcSTM2-VIGS flowers had reduced and defective gynoecia and a stronger reduction in the number of stamen than observed in EcSTM1-VIGS. Co-silencing of both genes led to more pronounced phenotypes. In addition, silencing of EcSTM2 alone or together with EcSTM1
resulted in altered patterns of internodal elongation and sometimes in
other floral defects. Our data suggest that some aspects of STM function present in Arabidopsis evolved already before the basal eudicots diverged from core eudicots.

Harvard Citation style: Stammler, A., Meyer, S., Plant, A., Townsley, B., Becker, A. and Gleissberg, S. (2013) Duplicated STM-like KNOX I genes act in floral meristem activity in Eschscholzia californica (Papaveraceae), Development Genes and Evolution, 223(5), pp. 289-301. https://doi.org/10.1007/s00427-013-0446-8

APA Citation style: Stammler, A., Meyer, S., Plant, A., Townsley, B., Becker, A., & Gleissberg, S. (2013). Duplicated STM-like KNOX I genes act in floral meristem activity in Eschscholzia californica (Papaveraceae). Development Genes and Evolution. 223(5), 289-301. https://doi.org/10.1007/s00427-013-0446-8