The Soybean GH2/4 Gene That Encodes a Glutathione S-Transferase Has a Promoter That Is Activated by a Wide Range of Chemical Agents

Transcriptional activation of the soybean (Glycine max) GH2/4 gene (also referred to as Gmhsp26-A) and increase in abundance of the GH2/4 mRNA (also referred to as pCE54) have been previously shown to occur following treatment of soybean seedlings with auxins, nonauxin analogs, heavy metals, and a variety of other agents. To determine whether the GH2/4 promoter is responsive to an array of different agents, we have analyzed the inducibility of the GH2/4 promoter fused to the beta-glucuronidase reporter gene in transgenic tobacco (Nicotiana tabacum) plants. We have shown that a wide variety of chemical agents induce this promoter in a tissue-specific and concentration-dependent manner. In addition, we have used an affinity-purified antibody raised against recombinant GH2/4 protein to show that the GH2/4 protein increases in response to auxin application and is localized in the cytosol of soybean cells. Recombinant GH2/4 protein can be purified to homogeneity on a glutathione-agarose resin, and the purified protein has glutathione S-transferase activity when assayed with the substrate 1-chloro-2,4-dinitrobenzene.