Phytopathology. 2014 Sep;104(9):964-9. doi: 10.1094/PHYTO-10-13-0294-R.
Embryo infection is important for efficient seed transmission of viroids. To identify the major pattern of seed transmission of viroids, we used in situ hybridization to histochemically analyze the distribution of Potato spindle tuber viroid (PSTVd) in each developmental stage of petunia (flowering to mature seed stages). In floral organs, PSTVd was present in the reproductive tissues of infected female × infected male and infected female × healthy male but not of healthy female × infected male before embryogenesis. After pollination, PSTVd was detected in the developed embryo and endosperm in all three crosses. These findings indicate that PSTVd is indirectly delivered to the embryo through ovule or pollen during the development of reproductive tissues before embryogenesis but not directly through maternal tissues as cell-to-cell movement during embryogenesis.
胚胎感染对于病毒的有效种子传播很重要。为了确定病毒的主要种子传播模式，我们使用原位杂交技术对矮牵牛（开花至成熟种子阶段）的各个发育阶段中马铃薯纺锤块茎类病毒（PSTVd）的分布进行了组织化学分析。在花器官中，PSTVd 存在于受感染的雌性×受感染的雄性和受感染的雌性×健康雄性的生殖组织中，但在胚胎发生之前不存在于健康的雌性×受感染的雄性中。授粉后，在所有三种杂交中均检测到发育中的胚胎和胚乳中的 PSTVd。这些发现表明，在胚胎发生之前生殖组织发育过程中，PSTVd 通过胚珠或花粉间接传递给胚胎，而不是通过胚胎发生过程中的母组织进行细胞间运动直接传递给胚胎。
