Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Center of Analysis and Measurement, Zhejiang University, Hangzhou, China.
PLoS Pathog. 2019 Feb 21;15(2):e1007607. doi: 10.1371/journal.ppat.1007607. eCollection 2019 Feb.
Most plant viruses are vectored by insects and the interactions of virus-plant-vector have important ecological and evolutionary implications. Insect vectors often perform better on virus-infected plants. This indirect mutualism between plant viruses and insect vectors promotes the spread of virus and has significant agronomical effects. However, few studies have investigated how plant viruses manipulate plant defenses and promote vector performance. Begomoviruses are a prominent group of plant viruses in tropical and sub-tropical agro-ecosystems and are transmitted by whiteflies. Working with the whitefly Bemisia tabaci, begomoviruses and tobacco, we revealed that C2 protein of begomoviruses lacking DNA satellites was responsible for the suppression of plant defenses against whitefly vectors. We found that infection of plants by tomato yellow leaf curl virus (TYLCV), one of the most devastating begomoviruses worldwide, promoted the survival and reproduction of whitefly vectors. TYLCV C2 protein suppressed plant defenses by interacting with plant ubiquitin. This interaction compromised the degradation of JAZ1 protein, thus inhibiting jasmonic acid defense and the expression of MYC2-regulated terpene synthase genes. We further demonstrated that function of C2 protein among begomoviruses not associated with satellites is well conserved and ubiquitination is an evolutionarily conserved target of begomoviruses for the suppression of plant resistance to whitefly vectors. Taken together, these results demonstrate that ubiquitination inhibition by begomovirus C2 protein might be a general mechanism in begomovirus, whitefly and plant interactions.
大多数植物病毒是由昆虫传播的，病毒-植物-媒介的相互作用具有重要的生态和进化意义。昆虫媒介通常在感染病毒的植物上表现更好。这种植物病毒和昆虫媒介之间的间接互利共生促进了病毒的传播，并具有重要的农艺学影响。然而，很少有研究调查植物病毒如何操纵植物防御并促进媒介性能。双生病毒是热带和亚热带农业生态系统中一种重要的植物病毒群体，由粉虱传播。我们与粉虱烟粉虱合作，发现缺乏卫星 DNA 的双生病毒 C2 蛋白负责抑制植物对粉虱媒介的防御。我们发现，番茄黄曲叶病毒（TYLCV）感染植物后，该病毒是世界上最具破坏性的双生病毒之一，促进了粉虱媒介的存活和繁殖。TYLCV C2 蛋白通过与植物泛素相互作用来抑制植物防御。这种相互作用破坏了 JAZ1 蛋白的降解，从而抑制了茉莉酸防御和 MYC2 调控的萜烯合酶基因的表达。我们进一步证明，与卫星无关的双生病毒 C2 蛋白的功能在双生病毒中得到很好的保守，泛素化是双生病毒抑制植物对白粉虱媒介抗性的一个保守目标。综上所述，这些结果表明，双生病毒 C2 蛋白抑制泛素化可能是双生病毒、粉虱和植物相互作用中的一种普遍机制。
