Plant BiP gene family: differential expression, stress induction and protective role against physiological stresses

In contrast to yeast or mammalian counterpart, BiP (Binding Protein) from several plant species, such as maize, tobacco, Arabidopsis and soybean, is encoded by a multigene family. A systematic characterization and analysis of soybean BiP expression have provided evidence for the existence of multiple, complex regulatory mechanisms controlling plant BiP gene expression. In support of this observation, the soybean BiP gene family has been shown to exhibit organ-specific expression and differential regulation in response to abiotic stresses through distinct signaling pathways. As a member of the stress-regulated HSP70 family of protein, the elucidation of plant BiP function and regulation is likely to lead do new strategies to enhance crop tolerance to environmental stress. Consistent with this observation, transgenic plants overexpressing soybean BiP have demonstrated to exhibit increased tolerance to ER (endoplasmic reticulum) stressors during seed germination and enhanced tolerance to water deficit during plant growth.