ReviewRegulationofUbiquitinationIsCentraltothePhosphateStarvationResponseWenboPan,1,2YaorongWu,1,*andQiXie1,2,*Assessileorganisms,plantshavedevelopednumerousstrategiestoovercomethelimitingavailabilityoftheessentialnutrientphosphateinnature.Recentstudiesrevealthatpost-translationalmodification(PTM)byubiquitinationisanimportantandcentralregulationmechanismintheplantphosphatestarvationresponse(PSR).Ubiquitinationpreciselymodulatesthestabilityandtraffickingofproteinsinresponsetotheheterogeneousphosphatesupplement.Inductionofautophagyprovidesnovelinsightsintothemolecularmechanismsunderphosphatestarvation.Inthisreview,wepresentanddiscussnovelfindingsontheregulationofdiversePSRsthroughubiquitination.Resolvingtheseregulationmechanismswillpavethewaytoimprovephosphateacquisitionandutilizationefficiencyincrops.OverviewofthePhosphateStarvationResponseandtheUbiquitinationSystemPhosphorusisanessentialelementforplantgrowthandamajorfactorlimitingcropproductionworldwide[1,2].However,only~20%ofappliedphosphorusfertilizer(mainlyinorganicphos-phate,Pi)isavailableforplants;inaddition,theexcessPifertilizerwashedoutintolakes,rivers,andotherwaterbodiescausessevereenvironmentalpollution.Unveilingthemolecularmecha-nismoftheplantPSRandimprovingPiacquisitionandutilizationefficiencyarekeyinsolvingtheseissues[2–4].Plantshaveevolvednumerousmorphological,physiological,biochemical,andmolecularmechanismstoimprovePiacquisitionefficiencyandPiutilizationefficiency(PUE)underPistar-vation:thePSR[1,3–8].First,plantsmodulatetheirrootsystemarchitecturebydevelopingshorterprimaryrootsandincreasinglateralrootlengthanddensitytoincreasetherootsurfacearea[5].Second,plantsimprovePiuptakeandtranslocationbyregulatingtheexpressionandactivityofPitransporters,suchasPHOSPHATETRANSPORTER1s(PHT1s)andPHOSPHATE1(PHO1).Third,plantssecreteorganicacidsandenzymes,suchasphospha-tases,toactivatePiinthesoilandincreasetheirassociationwithmycorrhizatoenhancePiuptake.Furthermore,Pistarvationalsomodulatesplantmetabolismpathways,s...
