The raspberry bushy dwarf virus 1b gene enables pollen grains to function efficiently in horizontal pollen transmission.

Horizontal pollen transmission by the raspberry bushy dwarf virus 1b deletion mutant (RBΔ1bstop), which is defective in virus virulence, was significantly decreased compared to wild-type raspberry bushy dwarf virus (wtRBDV). We assessed accumulation of viral genomic (g) RNAs in pollen grains from RBΔ1bstop-infected plants and found that the pollen grains had less viral gRNA than those from wtRBDV-infected plants. In addition, pollen grains from 1b-expressing transgenic plants (1b-plants) infected with RBΔ1bstop were more efficient in horizontal virus transmission to healthy plants after pollination than pollen from RBΔ1bstop-infected wild type plants. Moreover, viral gRNA accumulation in pollen grains from RBΔ1bstop-infected 1b-plants was higher than in pollen from RBΔ1bstop-infected wild type plants. We suggest that 1b increases the amount of viral gRNAs released from elongating pollen grains.

Evaluation of the Nutraceutical and Cosmeceutical Potential of Two Cultivars of Rubus fruticosus L. under Different Cultivation Conditions.

BACKGROUND: The starting point for the development of new, functional products derived from Rubus fruticosus L. is to determine the optimal cultivation conditions that produce maximal yield of fruits containing desirable bioactive properties. Towards that goal, the effect of soil, soil/peat mixture and light intensity on the nutraceutical and cosmeceutical potential of two cultivars ('Thornfree' and 'Loch Ness') of Rubus fruticosus L. were evaluated. METHODS: The assessment was carried out employing a range of methods for evaluating fruit properties associated with promoting good health such as total antioxidant capacity, secondary metabolites content (vitamin C, polyphenols, flavonoids and anthocyanins) and inhibition analysis of skin-regulating enzymes. RESULTS: 'Thornfree' cultivar produced fruits in all light conditions, while 'Loch Ness' did not produce fruits in low light conditions. The results showed that in Rubus fruticosus L. fruit, the chemical composition and bioactivity are strongly affected by both genetics factors and growing conditions. Extract from 'Thornfree' fruits obtained under low light and soil/peat conditions displayed superior properties such as high antioxidant capacity, high concentrations of phenolics, flavonoids and anthocyanins and high inhibitory potency towards the enzymes tyrosinase and elastase. This extract was used for the development of a topical skin care cream with excellent compatibility and stability. CONCLUSION: Our findings conclude that Rubus fruticosus L. cultivation may be efficiently and effectively manipulated through conventional cultivation techniques to produce promising bioactive ingredients with potential use in commercial cosmetics and pharmaceuticals.