ABSTRACT
Soybean (Glycine max (L.) Merr.) is one of the most important crops for oil and protein resource. Improvement of stress tolerance will be beneficial for soybean seed production.
Six GmPHD genes encoding Alfi n1-type PHD fi nger protein were identifi ed and their expressions differentially responded to drought, salt, cold, and ABA treatments. The six GmPHDs were nuclear proteins and showed ability to bind the cis-element “GTGGAG.” The N-terminal domain of GmPHD played a major role in DNA binding. Using a protoplast assay system, we fi nd that GmPHD1 to GmPHD5 had transcriptional suppression activity whereas GmPHD6 did not have. In yeast assay, the GmPHD6 can form homodimer and heterodimer with the other GmPHDs except GmPHD2. The N-terminal plus the variable regions but not the PHD-fi nger is required for the dimerization. Transgenic Arabidopsis plants overexpressing the GmPHD2 showed salt tolerance when compared with the wild type plants. This tolerance was likely achieved by diminishing the oxidative stress through regulation of downstream genes.
