Fig. 1.

Ethylene signalling affects total phosphorus changes and PhPT1 expression during petunia corolla senescence. (A) Natural senescence of unpollinated corollas from Petunia×hybrida ‘Mitchell Diploid’ (MD) wild-type plants and transgenic petunias with reduced sensitivity to ethylene (35S::etr1-1; lines Z00-35-10 and 44568). Flower longevity varied among MD and etr1-1 lines, therefore corollas were collected for nutrient and gene expression analyses at three stages of development (non-senescing—early, middle, and late) and three stages of senescence (senescing—early, middle, and late). (B) Corolla phosphorus content (mean ±SD, n=3) in MD and etr1-1 transgenic lines (Z00-35-10 and 44568) during flower development and senescence. (C) PhPT1 transcript levels (mean ±SD, n=3) in corollas. Relative mRNA abundance compared to PhACTIN was determined by quantitative RT-PCR. ND indicates expression levels were not determined.