NtPDR1, a plasma membrane ABC transporter from Nicotiana tabacum, is involved in diterpene transport

Abstract

ATP-binding cassette transporters are involved in the active transport of a wide variety of metabolites in prokaryotes and eukaryotes. One subfamily, the Pleiotropic Drug Resistance (PDR) transporters, or full-size ABCG transporters, are found only in fungi and plants. NtPDR1 was originally identified in Nicotiana tabacum suspension cells (BY2), in which its expression was induced by microbial elicitors. To obtain information on its expression in plants, we generated NtPDR1-specific antibodies and, using Western blotting, found that this transporter is localized in roots, leaves, and flowers and this was confirmed in transgenic plants expressing the ß-glucuronidase reporter gene fused to the NtPDR1 promoter region. Expression was seen in the lateral roots and in the long glandular trichomes of the leaves, stem, and flowers. Western blot analysis and in situ immunolocalization showed NtPDR1 to be localized in the plasma membrane. Induction of NtPDR1 expression by various compounds was tested in N. tabacum BY2 cells. Induction of expression was observed with the hormones methyl jasmonate and naphthalene acetic acid and diterpenes. Constitutive ectopic expression of NtPDR1 in N. tabacum BY2 cells resulted in increased resistance to several diterpenes. Transport tests directly demonstrated the ability of NtPDR1 to transport diterpenes. These data suggest that NtPDR1 is involved in plant defense through diterpene transport.

Arabidopsis ABCG34 contributes to defense against necrotrophic pathogens by mediating the secretion of camalexin

“…However, we did not find any conditions that allowed time-dependent loading of camalexin into cells. Similar difficulties in carrying out transport assays were reported for sclareol in BY2 cells (2). Direct transport assays of these secondary metabolites await further understanding of the chemical nature and permeability of the chemicals through lipid membranes.…”

“…Nicotiana plumbaginifolia PDR1/ABC1 and Nicotiana tabacum PDR1 are induced by jasmonate, a defense-related hormone highly expressed in the leaf epidermal cells and trichomes, and transport sclareol, a diterpene alcohol secreted by Nicotiana species in response to pathogen attack (2)(3)(4). Two functionally redundant Nicotiana benthamiana full-size ABCG transporters, NbABCG1 and NbABCG2, are essential for resistance to Phytophthora infestans.…”

The Role of Arabidopsis ABCG9 and ABCG31 ATP Binding Cassette Transporters in Pollen Fitness and the Deposition of Steryl Glycosides on the Pollen Coat

“…ABCG26 contributes to the deposition of pollen exine on the pollen surface (Quilichini et al, 2010;Xu et al, 2010;Choi et al, 2011;Dou et al, 2011). However, the functions of ABCGs are not restricted to lipid transfer, as many members of this group of proteins are also involved in biotic and abiotic stress responses, most likely by transporting terpenoids and their derivatives, as reported for Arabidopsis and other plants (Kang et al, 2011;Kuromori et al, 2011;Xi et al, 2012;Bienert et al, 2012;Crouzet et al, 2013). Despite numerous reports of ABC proteins having roles in lipid and terpenoid transport, so far, plant transporters have not been reported to be involved in the transport of sterols or their derivatives.…”

Mutant Allele-Specific Uncoupling of PENETRATION3 Functions Reveals Engagement of the ATP-Binding Cassette Transporter in Distinct Tryptophan Metabolic Pathways

“…The expression of plant genes encoding PDR proteins is often stimulated by microbial infection and defense phytohormones, such as salicylic acid (SA) and jasmonic acid. For example, tobacco (Nicotiana tabacum) PDR1, which is induced by Phytophthora infestans elicitins, flagellin, and methyl jasmonate, directly transports diterpenes in tobacco Bright Yellow-2 suspension cells (Sasabe et al, 2002;Crouzet et al, 2013). NtPDR5 is induced by methyl jasmonate and wounding and plays a role in herbivore resistance (Bienert et al, 2012).…”