ARS | Publication request: Eukaryotic release factor 1-2 is involved in GA signaling pathway and regulates cell elongation in petioles

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 10, 2009
Publication Date: April 10, 2009
Citation: Zhou, X., Cooke, P.H., Li, L. 2009. Eukaryotic release factor 1-2 is involved in GA signaling pathway and regulates cell elongation in petioles. Meeting Abstract.

Technical Abstract: Eukaryotic release factor 1 (eRF1) is responsible for recognition of the stop codons in mRNAs during protein synthesis. Accumulating evidence indicates that eRF1 functions in other processes in addition to translation termination. The physiological role of eRF1-2, a member of eRF1 family, was examined in Arabidopsis and cauliflower. eRF1-2 was found to localize in both cytoplasm and nuclear, which is consistent with its role in protein translation termination. Overexpression and knockout of eRF1-2 in Arabidopsis reversely regulated the plant responses to paclobutrazol, an inhibitor of GA biosynthesis. The eRF1-2 overexpressing transgenic lines showed enhanced sensitivity to paclobutrazol and exogenous GA restored their normal growth. In contrast, the loss-of-function erf1-2 mutant exhibited resistance to paclobutrazol, suggesting that eRF1-2 is a negative regulator in the GA signaling pathway. Analysis of transcript levels of GA biosynthetic and signaling component genes indicated that eRF1-2 probably participates in the GA signaling pathway through regulating the expression of GA3ox2 and affecting bioactive GA synthesis. Furthermore, alteration of the eRF1-2 expression also affected flowering time and shoot meristem tissue development in Arabidopsis. Transgenic cauliflower plants containing reduced transcript levels of erf1-2 were generated by RNA interference. The cauliflower transgenic lines displayed longer petioles, low levels of free sugars, and enhanced accumulation of anthocyanins. Cytological study of petiole epidermal cells revealed that the longer petioles were attributed to increased cell elongation. Taken together, these data provide evidence in supporting a novel role of eRF1-2 in GA signaling pathway in modulating plant growth and development.