The NADPH-oxidase AtrbohB plays a role in Arabidopsis seed after-ripening.
*Seeds can enter a state of dormancy, in which they do not germinate under optimal environmental conditions. Dormancy can be broken during seed after-ripening in the low-hydrated state. *By screening enhancer trap lines of Arabidopsis, we identified a role for the NADPH-oxidase AtrbohB in after-ripening. Semiquantitative PCR was used to investigate AtrbohB transcripts in seeds. These methods were complemented with a pharmacological approach using the inhibitor diphenylene iodonium chloride (DPI) and biomechanical measurements in the Brassicaceae seed model system cress (Lepidium sativum) as well as protein carbonylation assays. *atrbohB mutants fail to after-ripen and show reduced protein oxidation. AtrbohB pre-mRNA is alternatively spliced in seeds in a hormonally and developmentally regulated manner. AtrbohB is a major producer of superoxide in germinating Arabidopsis seeds, and inhibition of superoxide production by diphenylene iodonium (DPI) leads to a delay in Arabidopsis and cress seed germination and cress endosperm weakening. *Reactive oxygen species produced by AtrbohB during after-ripening could act via abscisic acid (ABA) signalling or post-translational protein modifications. Alternative splicing could be a general mechanism in after-ripening: by altered processing of stored pre-mRNAs seeds could react quickly to environmental changes.
Müller
Kerstin
K
Faculty of Biology, Institute for Biology II, Botany/Plant Physiology, University of Freiburg, Freiburg, Germany.
Carstens
Anna Catharina
AC
Linkies
Ada
A
Torres
Miguel Angel
MA
Leubner-Metzger
Gerhard
G
D000040:Abscisic Acid; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D056625:Endosperm; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000235:genetics / Q000502:physiology*; D029686:Lepidium / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D009861:Onium Compounds; D050050:Protein Carbonylation; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D012639:Seeds / Q000235:genetics / Q000502:physiology*; D013481:Superoxides
D029681:Arabidopsis Proteins; D009861:Onium Compounds; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D013481:Superoxides; C007517:diphenyleneiodonium; D000040:Abscisic Acid; D019255:NADPH Oxidases