Phospholipase D‐derived phosphatidic acid promotes root hair development under phosphorus deficiency by suppressing vacuolar degradation of PIN‐FORMED2

Abstract

Summary Root hair development is crucial for phosphate absorption, but how phosphorus deficiency affects root hair initiation and elongation remains unclear. We demonstrated the roles of auxin efflux carrier PIN‐FORMED2 (PIN2) and phospholipase D (PLD)‐derived phosphatidic acid (PA), a key signaling molecule, in promoting root hair development in Arabidopsis thaliana under a low phosphate (LP) condition. Root hair elongation under LP conditions was greatly suppressed in pin2 mutant or under treatment with a PLDζ2‐specific inhibitor, revealing that PIN2 and polar auxin transport and PLDζ2‐PA are crucial in LP responses. PIN2 was accumulated and degraded in the vacuole under a normal phosphate (NP) condition, whereas its vacuolar accumulation was suppressed under the LP or NP plus PA conditions. Vacuolar accumulation of PIN2 was increased in pldζ2 mutants under LP conditions. Increased or decreased PIN2 vacuolar accumulation is not observed in sorting nexin1 (snx1) mutant, indicating that vacuolar accumulation of PIN2 is mediated by SNX1 and the relevant trafficking process. PA binds to SNX1 and promotes its accumulation at the plasma membrane, especially under LP conditions, and hence promotes root hair development by suppressing the vacuolar degradation of PIN2. We uncovered a link between PLD‐derived PA and SNX1‐dependent vacuolar degradation of PIN2 in regulating root hair development under phosphorus deficiency.

A secretory phospholipase D hydrolyzes phosphatidylcholine to suppress rice heading time

“…Liposomal binding was performed as described [ 55 , 56 ] with few modifications. Briefly, Dioleoyl PC and dioleoyl PA (Avanti Polar Lipids, USA) were dissolved in chloroform and dried under nitrogen.…”

KAI2 promotes Arabidopsis root hair elongation at low external phosphate by controlling local accumulation of AUX1 and PIN2

“…KAI2 mediates local PIN2 accumulation at low but does not explain its increase at high external P i Similar to AUX1, the auxin exporter PIN-FORMED2 (PIN2) contributes to RH elongation at low P i and PIN2-GFP accumulates in response to ACC. 35,36 We used ethylene insensitive root 1 (eir1-1/pin2) mutants to examine whether PIN2 is required for RH elongation in response to KAR 2 and ACC at medium P i . As previously reported for pin2, eir1-1 had shorter RHL than the wild type; 36 moreover, it did not respond to KAR 2 and ACC (Figures S4D and S4E), showing that PIN2 is required for the RHL response to these compounds.…”

New Era of Diacylglycerol Kinase, Phosphatidic Acid and Phosphatidic Acid-Binding Protein

“…Yeast : Pah1 [ 183 ], Opi1p [ 38 , 184 ], Spo20p [ 38 , 185 , 186 ], Sso1p [ 187 ], Sec18p [ 188 , 189 ], Ups1 [ 190 , 191 ], Chm7 [ 192 ]. Plant : ABI1 [ 193 ], PP2CA [ 194 ], TGD2 [ 195 , 196 ], TGD4 [ 197 ], AtPDK1 [ 198 ], MKK7/9 [ 199 ], SnRK2.4 [ 200 ], PID [ 201 ], AtSphK1 [ 202 ], RGS1 [ 203 ], PEPC [ 204 ], LHY [ 205 ], CCA1 [ 205 ], Werewolf [ 206 ], AHL4 [ 207 ], AKT2 [ 208 ], MAP65-1 [ 209 ], RbohD160 [ 210 ], 14-3-3 protein [ 211 ], MtDef4 [ 211 ], NsD7 [ 212 ], SNX [ 213 ].…”