Essential Roles of the Linker Sequence Between Tetratricopeptide Repeat Motifs of Ethylene Overproduction 1 in Ethylene Biosynthesis

Ethylene Overproduction 1 (ETO1) is a negative regulator of ethylene biosynthesis. However, the regulation mechanism ETO1 remains largely unclear. Here, novel eto1 allele ( eto1-16 ) was isolated with typical triple phenotypes due to an amino acid substitution G480C in uncharacterized linker sequence between TPR1 and TPR2 motifs. Further genetic biochemical experiments confirmed mutation site. Sequence analysis revealed that G480 conserved not only two paralogs, EOL1 EOL2, Arabidopsis , but also homologous protein other species. The glycine mutations eto1-11 eto1-12 do influence mRNA abundance which reflected by secondary structure similar WT. According protein-protein interaction analysis, abnormal root phenotype might be caused disruption type 2 1-aminocyclopropane-1-carboxylic (ACC) synthases (ACSs) proteins. Overall, these data suggest tetratricopeptide repeat (TPR) motifs TPR or region are essential for bind downstream mediators, strengthens our knowledge balancing ACSs.