The Arabidopsis organelle-localized glycyl-tRNA synthetase encoded by EMBRYO DEFECTIVE DEVELOPMENT1 is required for organ patterning.
Leaves develop as planar organs, with a morphology that is specialized for photosynthesis. Development of a planar leaf requires genetic networks that set up opposing adaxial and abaxial sides of the leaf, which leads to establishment of dorsoventral polarity. While many genes have been identified that regulate adaxial and abaxial fate there is little information on how this is integrated with cellular function. EMBRYO DEFECTIVE DEVELOPMENT1 (EDD1) is a nuclear gene that encodes a plastid and mitochondrial localized glycyl-tRNA synthetase. Plants with partial loss of EDD1 function have changes in patterning of margin and distal regions of the leaf. In combination with mutations in the MYB domain transcription factor gene ASYMMETRIC LEAVES1 (AS1), partial loss of EDD1 function results in leaves with reduced adaxial fate. EDD1 may influence leaf dorsoventral polarity through regulating the abaxial fate genes KANADI1 (KAN1) and ETTIN (ETT)/AUXIN RESPONSE FACTOR3 (ARF3) since these genes are upregulated in the edd1 as1 double mutant. SCABRA3 (SCA3), a nuclear gene that encodes the plastid RNA polymerase is also required for leaf adaxial fate in the absence of AS1. These results add a novel component to networks of genetic regulation of leaf development and suggest that organelles, particularly plastids, are required in leaf patterning. Potentially, signalling from organelles is essential for coordination of different cell fates within the developing leaf.
John Innes Centre, Norwich, NR4 7UH, UK.
Alexis
A
Moschopoulos
Paul
P
Derbyshire
Mary E
ME
Byrne
D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D006032:Glycine-tRNA Ligase / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism; D018515:Plant Leaves / Q000254:growth & development*; D018087:Plastids / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
C456239:ASYMMETRIC LEAVES1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C109765:ETT protein, Arabidopsis; C430846:KANADI protein, Arabidopsis; D009687:Nuclear Proteins; D014157:Transcription Factors; C114546:edd1 protein, Arabidopsis; D000604:Amino Acyl-tRNA Synthetases; D006032:Glycine-tRNA Ligase