ABA IS MORE EFFECTIVE THAN ME-JA ON EXPRESSION OF SOME SENESCENCE-ASSOCIATED NACS IN ARABIDOPSIS

Abstract

Leaf senescence is an active and well-regulated degeneration process. Recent studies have shown that NAC transcription factors play an important role in the regulation of leaf senescence. ANAC019, ANAC055 and ANAC029 belong to same NAC sub-group (NAC-a) and they indicated as senescence-associated genes. The hormonal regulation of leaf senescence is a complex phenomenon and still not fully elucidated. ABA and me-JA are stress related plant hormones and accelerate leaf senescence. At the same time, these hormones not only stimulate leaf senescence but also make changes in gene expression. This study aimed to confirm to the effects of me-JA and ABA on the expression of ANAC019, ANAC055 and ANAC029 genes during leaf senescence in Arabidopsis thaliana. For this purpose, ABA and me-JA were applied to 34 day-old Arabidopsis leaves. After 6h of treatment, qPCR was performed to investigate relative expression of these genes on harvested leaves. The data showed that the expression level of ANAC019 was increased by ABA treatment but decreased after me-JA treatment. ABA treatment show increased expression of ANAC019, ANAC055 and ANAC029 genes while me-JA has induced effect on expression of ANAC055 gene. These results indicate that ABA is more effective than me JA on expression of senescence-associated NACs, ANAC019, ANAC055 and ANAC029, in Arabidopsis.