Table_3_Risk Assessment of Infectious Endogenous Banana Streak Viruses in Guadeloupe.XLSX

Infectious alleles of endogenous banana streak viruses (eBSVs) are present in the genome of all banana interspecific cultivars, including plantains and cooking types. Activation of these infectious eBSV alleles by biotic and abiotic stresses leads to spontaneous infections by cognate viruses and raises concerns about their ability to promote outbreaks of banana streak viruses under field cultivation conditions. We undertook a comprehensive risk assessment study of infectious eBSV alleles of species BSOLV, BSGFV and BSIMV in banana interspecific cultivars in Guadeloupe, a tropical island of the Caribbean where bananas are grown for export and local markets. We carried out a prevalence survey of BSOLV, BSGFV and BSIMV species in a range of cultivars grown in Guadeloupe. Our results suggest that BSOLV and BSGFV infections arise from the activation of infectious eBSVs rather than vector-borne transmission and point to a correlation between altitude and infection rates in interspecific hybrids with AAB genotypes. We studied the dynamics of activation of infectious eBSOLV and eBSGFV alleles by tissue culture and field cultivation in a range of cultivars. We showed that tissue culture and field cultivation trigger distinct activation pathways, resulting in distinct activation patterns. We also showed that activation decreased over time during cell culture and field cultivation and that BSV infections arising from the activation of infectious eBSV alleles cause symptomless infections in the most cultivated plantain in Guadeloupe, French Clair. Overall, our study shows that the risk of BSV outbreaks resulting from the activation of infectious eBSVs in plantain originating from vegetative multiplication is negligible in Guadeloupe.

所有香蕉种间栽培品种（包括大蕉与食用蕉类）的基因组中，均存在内源性香蕉线条病毒（endogenous banana streak viruses, eBSVs）的传染性等位基因。生物与非生物胁迫可激活这些传染性eBSV等位基因，引发同源病毒的自发侵染，这引发了学界对其在大田种植条件下诱发香蕉线条病毒暴发的能力的担忧。本研究针对加勒比热带岛屿瓜德罗普（当地香蕉兼具出口与本地市场种植属性）的香蕉种间栽培品种中，BSOLV、BSGFV与BSIMV物种的传染性eBSV等位基因开展了全面的风险评估。我们针对瓜德罗普境内种植的多个栽培品种，开展了BSOLV、BSGFV与BSIMV的流行率调查。研究结果显示，BSOLV与BSGFV的侵染源于传染性eBSVs的激活，而非媒介昆虫传播，同时表明海拔高度与AAB基因型种间杂种的病毒侵染率存在显著相关性。我们还针对多个栽培品种，探究了组织培养与大田种植条件下传染性eBSOLV与eBSGFV等位基因的激活动态变化。结果表明，组织培养与大田种植会触发不同的病毒激活通路，进而形成不同的激活模式。此外我们还发现，在细胞培养与大田种植过程中，病毒激活程度会随时间推移逐渐降低；且在瓜德罗普种植面积最广的大蕉品种French Clair中，由传染性eBSV等位基因激活引发的BSV侵染表现为无症状侵染。综上，本研究表明，在瓜德罗普地区，由无性繁殖大蕉的传染性eBSVs激活引发的BSV暴发风险可忽略不计。