Geminiviral Triggers and Suppressors of Plant Antiviral Immunity

Geminiviruses are circular single-stranded DNA plant viruses encapsidated into geminate virion particles, which infect many crops and vegetables and, hence, represent significant agricultural constraints worldwide. To maintain their broad-range host spectrum and establish productive infection, the geminiviruses must circumvent a potent plant antiviral immune system, which consists of a multilayered perception system represented by RNA interference sensors and effectors, pattern recognition receptors (PRR), and resistance (R) proteins. This recognition system leads to the activation of conserved defense responses that protect plants against different co-existing viral and nonviral pathogens in nature. Furthermore, a specific antiviral cell surface receptor signaling is activated at the onset of geminivirus infection to suppress global translation. This review highlighted these layers of virus perception and host defenses and the mechanisms developed by geminiviruses to overcome the plant antiviral immunity mechanisms.