Differential expression of the soybean BiP gene family

The soybean binding protein (BiP) gene family consists of at least four mem bers designated soyBiPA, soyBiPB, soyBiPC and soyBiPD. We have performed im munoblotting of two-dimensional (2D) gels and RT-PCR assays with gene-speci fic primers to analyze the differential expression of this gene family in v arious soybean organs. The 2D gel profiles of the BiP forms from different organs were distinct and suggested that the BiP genes are under organ-speci fic regulation. In fact, while all four BiP transcripts were detected in le aves by gene-specific reverse transcriptase-polymerase chain reaction (RT-P CR) assays, different subsets were detected in the other organs. The soyBiP D was expressed in all organs, whereas the expression of the soyBiPB was re stricted to leaves. The soyBiPA transcripts were detected in leaves, roots and seeds and soyBiPC RNA was confined to leaves, seeds and pods. Our data are consistent with organ-specific expression of the soybean BiP gene famil y. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.