Expression Analysis And Functional Exploration Of Atdtx18, A Member Of Mate Family In Arabidopsis

A new family of secondary transporters is referred as the MATE(multidrug and toxic compound extrusion)family. These proteins mediate resistance to a wide range of cationic dyes, aminoglycosides and other structurally diverse antibiotics and drugs. In Arabidopsis, MATE family contain at least 56 distinct genes. Microarray analysis shows most of these genes response to external biotic or abiotic stress. These results imply MATEs may play an important roles in plant tolerance to external stresses. One of the candidate, mediating signal transduction between external stress and MATEs is Jasmonic acid. As we all know, JA is one of the stress-inducible phytohormones, involved in response to wounding, pathogens, osmotic stress and ozone.In this paper, AtDTX18, one of MATE family gene, is chosen as a target for expression pattern analysis and functional characteristic.The main results of this paper are as follows:1) Semi-quantities RT-PCR and promoter gus fusion transgenic plant analysis show that treatment of wild type plant with MJ result in a rapid induction of AtDTX18 expression. We also find the level of AtDTX18 transcript significantly reduced in mutant coil and ein2, that block either jasmonate (coil) or ethylene( ein2) signaling pathways. These findings suggest the expression of AtDTX18 requires both hormone-signaling pathways.2) Using green fluorescent protein (GFP)fusions, the protein localizes to a organelle.3) Comparing with the wild type plant, we find the overexpressed transgenic plants have differentiable changes in color and the shape of leave. Furthermore the transgenic plants show partial sterile. So we speculate overexpression of AtDTX18 affect the biosynthesis of some colored metabolite. Aberrant accumulation of this substance in flower may affect the fertility of this plant.4) We also find the expression level of PDF1.2 reduced in mutant atdtx18 background. PDF1. 2 is known as a JA and ET signal response protein, involved in pathogen induced signal pathway. Whether AtDTX18 is also function as a pathogen-related protein remains further identified.