BpMADS4 has a central role in inflorescence initiation in silver birch (Betula pendula).

Acceleration of flowering would be beneficial for breeding trees with a long juvenile phase; conversely, inhibition of flowering would prevent the spread of transgenes from the genetically modified trees. We have previously isolated and characterized several MADS genes from silver birch (Betula pendula Roth). In this study, we investigated the more detailed function of one of them, BpMADS4, a member of the APETALA1/FRUITFULL group of MADS genes.

Functional characterization of SEPALLATA3 and AGAMOUS orthologues in silver birch.

The development of flowers is regulated by a complex network of transcriptional activators and repressors, many of which belong to the MADS box gene family. In this study, we describe two MADS box genes of silver birch (Betula pendula Roth), BpMADS1 and BpMADS6, which are similar to SEPALLATA3 and AGAMOUS in Arabidopsis thaliana, respectively. In situ hybridization showed that BpMADS1 was expressed in the inflorescence meristem at a very early stage, but not later.

A new SBP-box gene BpSPL1 in silver birch (Betula pendula).

The SBP-box gene family represents a group of plant-specific genes encoding putative transcription factors. Thus far, SBP-domain protein binding sites have been found in the promoters of Arabidopsis APETALA1 and Antirrhinum SQUAMOSA. A putative SBP-domain binding element has been observed in the promoter of BpMADS5, a close homologue of Arabidopsis FRUITFULL in silver birch (Betula pendula).

Glutamine synthetase isozymes in germinating barley seeds.

Glutamine synthetase (GS; EC 6.3.1.