A pleiotropic drug resistance transporter in Nicotiana tabacum is involved in defense against the herbivore Manduca sexta

Abstract

SUMMARYPleiotropic drug resistance (PDR) transporters are a group of membrane proteins belonging to the ABCG subfamily of ATP binding cassette (ABC) transporters. There is clear evidence for the involvement of plant ABC transporters in resistance to fungal and bacterial pathogens, but not in the biotic stress response to insect or herbivore attack. Here, we describe a PDR transporter, ABCG5/PDR5, from Nicotiana tabacum. GFP fusion and subcellular fractionation studies revealed that ABCG5/PDR5 is localized to the plasma membrane. Staining of transgenic plants expressing the GUS reporter gene under the control of the ABCG5/PDR5 transcription promoter and immunoblotting of wild-type plants showed that, under standard growth conditions, ABCG5/ PDR5 is highly expressed in roots, stems and flowers, but is only expressed at marginal levels in leaves. Interestingly, ABCG5/PDR5 expression is induced in leaves by methyl jasmonate, wounding, pathogen infiltration, or herbivory by Manduca sexta. To address the physiological role of ABCG5/PDR5, N. tabacum plants silenced for the expression of ABCG5/PDR5 were obtained. No phenotypic modification was observed under standard conditions. However, a small increase in susceptibility to the fungus Fusarium oxysporum was observed. A stronger effect was observed in relation to herbivory: silenced plants allowed better growth and faster development of M. sexta larvae than wild-type plants, indicating an involvement of this PDR transporter in resistance to M. sexta herbivory.

Beyond cellular detoxification: a plethora of physiological roles for MDR transporter homologs in plants

“…Interestingly, AtABCG36, AtABCG37, and AtABCG30 are involved in root exudation of phytochemicals (Badri et al, 2009, 2012). Recent studies implicate the tobacco NtPDR5 in herbivore defense (Bienert et al, 2012), while the wheat PDR carrier LR34 confers resistance to fungal pathogens (Krattinger et al, 2009; Risk et al, 2013). Thus, plant full-size ABCG proteins play a preponderant role in metal and xenobiotic detoxification as well as in biotic stress resistance, but also fulfill functions in phytohormone transport.…”

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

“…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). Nicotiana plumbaginifolia PDR1 transports diterpene sclareol and is induced by pathogen colonization or jasmonic acid treatment (Stukkens et al, 2005).…”