The Senescence-Associated Endonuclease, PhENDO1, Is Upregulated by Ethylene and Phosphorus Deficiency in Petunia

The upregulation of endonuclease activities and subsequent decreases in the nucleic acid content leaves petals are characteristics senescence that allow for nutrient remobilization from dying organs. We previously identified a 43-kDa activity (PhNUC1) was upregulated Petunia × hybrida during senescence. PhNUC1 has optimal at neutral pH, is enhanced by Co2+, degrades both DNA RNA. peptide sequence senescing 2-dimensional gel electrophoresis used to clone gene (PhENDO1) encoding senescence-associated protein. PhENDO1 expression unpollinated pollinated flowers ethylene treatment. When petunias were grown under deficient conditions, P-starvation, lesser extent N-starvation, induced PhENDO1. endogenous down regulated using virus silencing (VIGS), in-gel assays confirmed decreased corollas PhENDO1-silenced (pTRV2:PhCHS:PhENDO1) plants compared controls (pTRV2:PhCHS). Down regulating did not alter flower longevity. While may be involved catabolism senescence, this VIGS sufficient delay