MATE Transporter-Dependent Export of Hydroxycinnamic Acid Amides

Abstract

The ability of Arabidopsis thaliana to successfully prevent colonization by Phytophthora infestans, the causal agent of late blight disease of potato (Solanum tuberosum), depends on multilayered defense responses. To address the role of surfacelocalized secondary metabolites for entry control, droplets of a P. infestans zoospore suspension, incubated on Arabidopsis leaves, were subjected to untargeted metabolite profiling. The hydroxycinnamic acid amide coumaroylagmatine was among the metabolites secreted into the inoculum. In vitro assays revealed an inhibitory activity of coumaroylagmatine on P. infestans spore germination. Mutant analyses suggested a requirement of the p-coumaroyl-CoA:agmatine N4-p-coumaroyl transferase ACT for the biosynthesis and of the MATE transporter DTX18 for the extracellular accumulation of coumaroylagmatine. The host plant potato is not able to efficiently secrete coumaroylagmatine. This inability is overcome in transgenic potato plants expressing the two Arabidopsis genes ACT and DTX18. These plants secrete agmatine and putrescine conjugates to high levels, indicating that DTX18 is a hydroxycinnamic acid amide transporter with a distinct specificity. The export of hydroxycinnamic acid amides correlates with a decreased ability of P. infestans spores to germinate, suggesting a contribution of secreted antimicrobial compounds to pathogen defense at the leaf surface.

Two tonoplast MATE proteins function as turgor-regulating chloride channels in Arabidopsis

“…3 D and E). The DTX33 and DTX35 transporters were not significantly permeable to organic acids, including citric acid and malate, in contrast to the MATE transporters described previously, including those mediating aluminum tolerance (18)(19)(20)(21)(22)29). It is noteworthy that both DTX members are slightly permeable to nitrate, which can be an abundant inorganic anion in plant cells under certain soil conditions.…”

“…We then measured the transport activity of isolated vacuoles from fluorescence-labeled cells by patch-clamp procedure (28). Several studies indicated that DTX/ MATE-type proteins transport organic acids, such as citric acid (18)(19)(20)(21)(22)29). We examined the possibility that DTX33 and DTX35 may function as anion transporters, like those reported earlier.…”

“…1073/pnas.1616203114/-/DCSupplemental. recent study indicates that DTX18 exports hydroxycinnamic acid amides to the leaf surface, inhibiting germination of Phytophthora infestans spores (22).…”

Jasmonic acid/ethylene signaling coordinates hydroxycinnamic acid amides biosynthesis through ORA59 transcription factor

“…As expected, the AtACT gene expression was strongly reduced in both coi1‐1 and ein2‐1 mutants compared with the WT. Recently, the key Multidrug And Toxin Extrusion (MATE) transporter gene DTX18 was characterized for extracellular accumulation of HCAA (Dobritzsch et al ., ). Interestingly, our results showed that the DTX18 expression pattern was similar to AtACT in the different genetic backgrounds (Figure S5).…”

A PAMP‐triggered MAPK cascade inhibits phosphatidylinositol 4,5‐bisphosphate production by PIP5K6 in Arabidopsis thaliana

“…A possible biologically relevant role for a PAMP‐induced decrease in PtdIns(4,5)P 2 may thus be to mediate a transient halt of endocytotic recycling of activated plasma membrane proteins with roles in defense, possibly to enable optimal activity against surrounding microbes before being recycled from the plasma membrane. Besides RbohD (Kadota et al ., ; Li et al ., ), this may also affect the multidrug exporter DTX18 (Dobritzsch et al ., ). It should be noted that the proposed flg22‐triggered delay in CME of plasma membrane proteins appears to contrast with reported flg22‐induced endocytosis of FLS2 (Robatzek et al ., ; Ben Khaled et al ., ; Frescatada‐Rosa et al ., ).…”