A new oxidative pathway of nitric oxide production from oximes in plants  

作　　者：Pedro Lopez-Gomez Javier Buezo Marina Urra Alfonso Cornejo Raquel Esteban Jorge Fernandez de los Reyes Estibaliz Urarte Estefania Rodriguez-Dobreva Alejandro Chamizo-Ampudia Alejandro Eguaras Sebastian Wolf Daniel Marino Victor Martinez-Merino Jose F.Moran 

机构地区：[1]Institute for Multidisciplinary Research in Applied Biology(IMAB),Department of Sciences,Public University of Navarre(UPNA),Avda.de Pamplona 123,31192 Mutilva,Spain [2]Institute for Advanced Materials and Mathematics(INAMAT2),Department of Sciences,Public University of Navarre(UPNA),Campus de Arosadia,31006 Pamplona,Spain [3]Department of Plant Biology and Ecology,University of the Basque Country(UPV/EHU),Sarriena s/n,Apdo.644,48080 Bilbao,Spain [4]Center for Plant Molecular Biology(ZMBP),University of Tubingen,Geschwister-Scholl-Platz,72074 Tubingen,Germany [5]Institute of Natural Resources and Agrobiology of Salamanca(IRNASA),Department of Plant-Microorganism Interactions,Spanish National Research Council(CSIC),Cordel de Merinas,40-52,37008,Salamanca,Spain [6]Department of Biochemistry,Area of Molecular Biology,Veterinary Faculty,University of Leon,Campus de Vegazana,s/n.,24071 Leon,Spain

出　　处：《Molecular Plant》2024年第1期178-198,共21页分子植物（英文版）

基　　金：supported by grants AGL2014-52396,AGL2017-86293-P,and PID2022-142968NB-I00 from MCIN/AEI/10.13039/501100011033/FEDER,UE,and a grant from the Public University of Navarre(PID-2020-117703GB-I00)(to J.F.M.)and the UPV/EHU-GV IT-1018-16 program(Basque Government)(to R.E.).M.U.is a recipient of a predoctoral fellowship from the Government of Navarre,Spain.J.B.and P.L.-G.have received pre-doctoral fellowships from the Public University of Navarre,Spain.P.L.-G is currently financed by a postdoctoral contract funded by the Spanish National Research Council(20224AT017).J.B.is also a recipient of the"Requalification of the Spanish University System for 2021-2023,Public University of Navarra"fellowship,funded by the European Union-Next Generation(EU).

摘　　要：Nitric oxide(NO)is an essential reactive oxygen species and a signal molecule in plants.Although several studies have proposed the occurrence of oxidative NO production,only reductive routes for NO production,such as the nitrate(NO_(3)^(-))-upper-reductase pathway,have been evidenced to date in land plants.However,plants grown axenically with ammonium as the sole source of nitrogen exhibit contents of nitrite and NO3−,evidencing the existence of a metabolic pathway for oxidative production of NO.We hypothesized that oximes,such as indole-3-acetaldoxime(IAOx),a precursor to indole-3-acetic acid,are intermediate oxidation products in NO synthesis.We detected the production of NO from IAOx and other oximes catalyzed by peroxidase(POD)enzyme using both 4-amino-5-methylamino-2′,7′-difluorescein fluorescence and chemiluminescence.Flavins stimulated the reaction,while superoxide dismutase inhibited it.Interestingly,mouse NO synthase can also use IAOx to produce NO at a lower rate than POD.We provided a full mechanism for POD-dependent NO production from IAOx consistent with the experimental data and supported by density functional theory calculations.We showed that the addition of IAOx to extracts from Medicago truncatula increased the in vitro production of NO,while in vivo supplementation of IAOx and other oximes increased the number of lateral roots,as shown for NO donors,and a more than 10-fold increase in IAOx dehydratase expression.Furthermore,we found that in vivo supplementation of IAOx increased NO production in Arabidopsis thaliana wild-type plants,while prx33-34 mutant plants,defective in POD33-34,had reduced production.Our data show that the release of NO by IAOx,as well as its auxinic effect,explain the superroot phenotype.Collectively,our study reveals that plants produce NO utilizing diverse molecules such as oximes,POD,and flavins,which are widely distributed in the plant kingdom,thus introducing a long-awaited oxidative pathway to NO production in plants.This knowledge has essential implications f

关 键 词：ammonium oxidation AUXIN nitric oxide OXIME PEROXIDASE root phenotype 

分 类 号：Q94[生物学—植物学]