摘要
Plants resist viral infection through multiple mechanisms.These include physical barriers,activation of NUCLEOTIDE-BINDING LEUGINE-RICH REPEAT PROTEINS(NLRs),autophagy,biosyn-thesis of defense-related phytohormones,and RNA interference(RNAi).RNAI suppresses the expression of viral RNA and is conserved across several eukaryotic kingdoms.During infection,RNA-DEPENDENT RNA POLYMERASES(RDRs)amplify viral RNA fragments into double-stranded RNAs(dsRNAs).