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Multidrug and Toxic Compound Extrusion-Type Transporters Implicated in Vacuolar Sequestration of Nicotine in Tobacco Roots1[C][W]
- Publication Year :
- 2009
- Publisher :
- American Society of Plant Biologists, 2009.
-
Abstract
- Nicotine is a major alkaloid accumulating in the vacuole of tobacco (Nicotiana tabacum), but the transporters involved in the vacuolar sequestration are not known. We here report that tobacco genes (NtMATE1 and NtMATE2) encoding transporters of the multidrug and toxic compound extrusion (MATE) family are coordinately regulated with structural genes for nicotine biosynthesis in the root, with respect to spatial expression patterns, regulation by NIC regulatory loci, and induction by methyl jasmonate. Subcellular fractionation, immunogold electron microscopy, and expression of a green fluorescent protein fusion protein all suggested that these transporters are localized to the vacuolar membrane. Reduced expression of the transporters rendered tobacco plants more sensitive to the application of nicotine. In contrast, overexpression of NtMATE1 in cultured tobacco cells induced strong acidification of the cytoplasm after jasmonate elicitation or after the addition of nicotine under nonelicited conditions. Expression of NtMATE1 in yeast (Saccharomyces cerevisiae) cells compromised the accumulation of exogenously supplied nicotine into the yeast cells. The results imply that these MATE-type proteins transport tobacco alkaloids from the cytosol into the vacuole in exchange for protons in alkaloid-synthesizing root cells.
- Subjects :
- Nicotine
DNA, Complementary
DNA, Plant
Organic Cation Transport Proteins
Sequence Homology, Amino Acid
Green Fluorescent Proteins
Molecular Sequence Data
Cyclopentanes
Transfection
Plant Roots
Drug Resistance, Multiple
Alkaloids
Genes, Reporter
Tobacco
Vacuoles
Oxylipins
Cloning, Molecular
Sequence Alignment
Research Article
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.pmid..........9dc6c66dc606b01db6fc7c8eff7dfd2d