Characterization of Root-Specific a -Dioxygenasel Promoter in Tomato

摘要

The availability of tissue-specific promoters can dramatically increase the successful application of transgenic technology. For isolation of root-specific promoter, 11 tomato ESTs, predicted as expressed in a tissue-specific manner by in silico Audio's test, were selected for further analysis. An EST encoding alpha-Dioxygenasel (OL-DOX1) gene, catalyzing the oxygenation of fatty acids to yield oxylipin, was selected t(tbe root-specific based on RT-PCR analysis. Promoter region of 0.-DOX1 was isolated by PCR method. Putative czs-acting elements, such as root-specificity and phytohormones responsiveness, were predicted by Plant cis-acting regulatory DNA elements program (PLACE). Promoter deletion fragments were amplified based on putative cis-actingelement analysis, then cloned into pCAMBIA1391z for driving the expression of beta-glucuronidase (GUS) gene. These constructs were transformed into Arabiopsis thaliana by floral dip method. T_1 transgenic seeds were harvested for further characterization. The GUS expression of transgenic line S1DOX1P10 and S1DOX1P05 was only observed in root tissues. Phytohormones and salt-responsiveness in these transgenic Arabidopsis were also shown by Histochemical GUS staining. The promoter could be used as a usefultool for expression of foreign gene in plant root.