Insect Control & Cotton Disease Research Unit, Plains Area, Agricultural Research Service, United States Department of Agriculture, College Station, Texas, United States of America.
PLoS One. 2020 Dec 3;15(12):e0242988. doi: 10.1371/journal.pone.0242988. eCollection 2020.
Southern green stink bug [Nezara viridula (L.)] adults and other pentatomid pests can transmit pathogens (e.g., the bacterium Pantoea agglomerans) that cause disease in cotton (Gossypium hirsutum L.) and other high-value cash crops worldwide. First instars of N. viridula were recently shown to ingest P. agglomerans strain Sc1R with rifampicin-resistance, and to retain the pathogen to the 2nd instar. The objective of this study was to determine the acquisition of P. agglomerans Sc1R by early instars of N. viridula and determine persistence of P. agglomerans Sc1R across subsequent stadia. In three trials, early instars (1st and 2nd) were exposed to P. agglomerans Sc1R and subsequently maintained to adulthood; cohorts were sampled at 3rd and 5th instars, as well as adults. In every trial, P. agglomerans Sc1R was detected in all stadia, including adults, but significantly higher frequencies of infection than expected were observed at the initial stage of infection (either 1st or 2nd instar). Higher densities of P. agglomerans Sc1R were detected in 1st and 2nd instars, and lower densities were observed in subsequent stadia. Densities of innate microbiota were generally lower when the initial stage of exposure was at 1st instar than when the initial stage of exposure was at the 2nd instar. Overall, half of the adults possessed P. agglomerans Sc1R. These findings demonstrated that N. viridula nymphs can acquire P. agglomerans Sc1R and retain the pathogen to adulthood. Potential avenues of research to further elucidate the implications of nymphs harboring pathogens to adulthood are discussed.
南方绿椿象[Nezara viridula（L.）]成虫和其他半翅目害虫可传播病原体（例如 Pantoea agglomerans 细菌），导致全球棉花（Gossypium hirsutum L.）和其他高价值经济作物患病。最近研究表明，南方绿椿象的 1 龄若虫可摄取携带利福平抗性的 P. agglomerans 菌株 Sc1R，并将病原体保留到 2 龄。本研究旨在确定南方绿椿象早期若虫对 P. agglomerans Sc1R 的获得情况，并确定 P. agglomerans Sc1R 在随后的各个龄期的持续存在情况。在三项试验中，早期若虫（1 龄和 2 龄）暴露于 P. agglomerans Sc1R，随后饲养至成虫；在 3 龄和 5 龄以及成虫时采集样本。在每一项试验中，均在所有龄期（包括成虫）中检测到 P. agglomerans Sc1R，但在感染的初始阶段（1 龄或 2 龄）观察到的感染频率明显高于预期。在 1 龄和 2 龄若虫中检测到更高密度的 P. agglomerans Sc1R，而在随后的龄期中观察到的密度较低。当暴露的初始阶段为 1 龄时，固有微生物群的密度通常低于暴露的初始阶段为 2 龄时。总体而言，有一半的成虫携带 P. agglomerans Sc1R。这些发现表明，南方绿椿象若虫可以获得 P. agglomerans Sc1R 并将病原体保留到成虫期。讨论了进一步阐明携带病原体的若虫成虫的潜在研究途径。
