Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153-8902, Japan.
Mol Plant Pathol. 2003 Jul 1;4(4):259-69. doi: 10.1046/j.1364-3703.2003.00174.x.
SUMMARY Cross-protection is a procedure that has been utilized to protect crops against virulent strains of viruses by pre-treatment with closely related attenuated strains of the virus. We constructed a mutant of crucifer tobamovirus Cg, which is analogous to L(11)A, an attenuated strain of Tomato mosaic virus-L (ToMV-L). This mutant, named CgYD, caused few disease symptoms and could spread throughout Arabidopsis thaliana Col-0 plants. Initial infection with CgYD was shown to efficiently cross-protect against a challenge with wild-type Cg. Thus, we have established in Arabidopsis a powerful system for investigating mechanisms of cross-protection. Using this system, we showed that cross-protection was not overcome, even if a higher concentration of the virion, or purified virion RNA, were used in the challenge. We also demonstrated that cross-protection requires that the second virus be very similar in sequence to Cg, which is a characteristic of RNA silencing. However the RNA dependent RNA polymerase SDE1/SGS2 associated with post-transcriptional gene silencing was not required for cross-protection.
摘要 交叉保护是一种通过用相关的弱毒株预先处理来保护作物免受强毒株病毒侵害的方法。我们构建了拟南芥菜花叶病毒 Cg 的一个突变株，类似于番茄花叶病毒-L（ToMV-L）的弱毒株 L(11)A。该突变株命名为 CgYD，引起的病症很少，能够在拟南芥 Col-0 植株中传播。最初的 CgYD 感染能有效地对野生型 Cg 的攻击产生交叉保护。因此，我们在拟南芥中建立了一个强大的系统来研究交叉保护的机制。利用该系统，我们表明，即使在挑战中使用更高浓度的病毒粒子或纯化的病毒粒子 RNA，交叉保护也不会被克服。我们还表明，交叉保护需要第二个病毒与 Cg 非常相似，这是 RNA 沉默的一个特征。然而，与转录后基因沉默相关的 RNA 依赖的 RNA 聚合酶 SDE1/SGS2 并不需要用于交叉保护。
