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.

中文翻译：

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覆盆子丛生矮化病毒 1b 基因使花粉粒能够在花粉水平传播中有效发挥作用。


与野生型覆盆子丛矮病毒（wtRBDV）相比，病毒毒力有缺陷的覆盆子丛矮病毒1b缺失突变体（RBΔ1bstop）的花粉水平传播显着降低。我们评估了 RBΔ1bstop 感染植物花粉粒中病毒基因组 (g) RNA 的积累，发现花粉粒中的病毒 gRNA 少于 wtRBDV 感染植物。此外，与来自感染RBΔ1bstop的野生型植物的花粉相比，来自感染RBΔ1bstop的表达1b的转基因植物（1b-植物）的花粉在授粉后将病毒水平传播到健康植物的效率更高。此外，感染 RBΔ1bstop 的 1b 植物花粉中的病毒 gRNA 积累量高于感染 RBΔ1bstop 的野生型植物花粉中的病毒 gRNA 积累。我们认为 1b 增加了从拉长的花粉粒中释放的病毒 gRNA 的数量。