1. Study Of The Cold Tolerance Induced By Hrf1in Sweet Corn2. Expression Of DvCRP1/2in Dunalie-lla Viridis Under The Stress Of Cd²⁺ And The Combination Analysis Of Gst-dvcr-p1/2with Cu²⁺

In previous studies, Hrf1protein（a kind of Harpinxoofrom Xanthomonas oryzaepv. oryzae）fused with His tag could improve the speed and the rate of germination ofsweet corn W22-su1/su1significantly and increase the activity of the catalase (CAT)under the cold stress. The objective of this work was to demonstrate the mechanismof this cold tolerance. After treated with Hrf1, no significant change of total proteinand starch were detected in seeds under the cold stress. Superoxide dismutase (SOD)was induced highly at RNA and protein levels in seeds after Hrf1treatment comparedwith contrast under the cold stress. Conductivity increased distinctly and malondialde-hyde (MDA) level was not changed seriously in the leaves at the3rd leaf stage aftertreated with Hrf1under the cold stress. Furthermore, the expression of pyrroline-5-carboxylate synthetase-1(P5CS1) was also increased. The fresh and the dry weight ofseedlings went up. These results indicated that Hrf1could improve the cold toleranceof sweet corn W22-su1/su1and enhance plants growth by maintaining the cell membr-ane stability, improving the expression of plant antioxidase and osmotic stress resista-nce genes. Yeast two hybridization assay showed that Hrf1and its’two homologs(Hrf2and Hrf3) could interact with maize Harpin binding protein (Hrbp). Interesting-ly, Hrf2could interact with itself. This study provides some clues about the mechanis-m of plant cold tolerance induced by Hrf1.