Isolation and expression patterns of two novel senescence-associated genes RhAA and RhCG in rose (Rosa hybrida)

The functional life and marketability of flowers is restricted by senescence and / or abscission. Many senescence-associated genes have been identified in the Arabidopsis plant. In this research, we isolated two full length clones of RhAA and RhCG in rose (Rosa hybrida) and compared the expression patterns of these genes in cultivars with short ('Cool Water') and long ('Marroussia') shelf lives. The RhAA gene is more similar to unknown proteins Cucurbita maxima, Gossypium arboretum and senescence-associated protein Medicago truncatula, while the RhCG is closer to the unknown proteins Pisum sativum and Dendrobium catenattum. The results of quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that the RhAA was expressed at higher levels in at the bud and open stages in most tissues of 'Cool water' compared with 'Marroussia' in response to the ethylene treatment. In gynoecia, the RhCG gene showed the highest level of expression in both cultivars at the second and seventh stages. It seems that the RhAA and RhCG were encoding a plant-specific protein of unknown function, which may relate to in the degradative and remobilization processes of senescence.