Scully Erin D, Donze-Reiner Teresa, Wang Haichuan, Eickhoff Thomas E, Baxendale Frederick, Twigg Paul, Kovacs Frank, Heng-Moss Tiffany, Sattler Scott E, Sarath Gautam
Stored Product Insect and Engineering Research Unit, Center for Grain and Animal Health Research USDA-ARS, Manhattan, KS 66502, USA.
Department of Biology, West Chester University, West Chester, PA 19382, USA.
Funct Plant Biol. 2016 Dec;43(12):1134-1148. doi: 10.1071/FP16104.
Knowledge of specific peroxidases that respond to aphid herbivory is limited in C4 grasses, but could provide targets for improving defence against these pests. A sorghum (Sorghum bicolor (L.) Moench) peroxidase (SbPrx-1; Sobic.002G416700) has been previously linked to biotic stress responses, and was the starting point for this study. Genomic analyses indicated that SbPrx-1 was part of a clade of five closely related peroxidase genes occurring within a ~30kb region on chromosome 2 of the sorghum genome. Comparison of this ~30-kb region to syntenic regions in switchgrass (Panicum virgatum L.) and foxtail millet (Setaria italica L.) identified similar related clusters of peroxidases. Infestation of a susceptible sorghum cultivar with greenbugs (Shizaphis graminum Rondani) induced three of the five peroxidases. Greenbug infestation of switchgrass and foxtail millet plants showed similar inductions of peroxidases. SbPrx-1 was also induced in response to aphid herbivory in a greenbug-resistant sorghum line, Cargill 607E. These data indicate that this genomic region of C4 grasses could be valuable as a marker to assess potential insect resistance in C4 grasses.
在C4禾本科植物中，关于对蚜虫取食有反应的特定过氧化物酶的了解有限，但这可能为改善对这些害虫的防御提供靶点。一种高粱（Sorghum bicolor (L.) Moench）过氧化物酶（SbPrx-1；Sobic.002G416700）先前已与生物胁迫反应相关联，并且是本研究的起点。基因组分析表明，SbPrx-1是高粱基因组第2号染色体上一个约30kb区域内五个紧密相关的过氧化物酶基因进化枝的一部分。将这个约30kb的区域与柳枝稷（Panicum virgatum L.）和谷子（Setaria italica L.）的同线区域进行比较，发现了类似的过氧化物酶相关簇。用麦二叉蚜（Shizaphis graminum Rondani）侵染一个易感高粱品种会诱导五个过氧化物酶中的三个。对柳枝稷和谷子植株进行麦二叉蚜侵染显示出过氧化物酶有类似的诱导情况。在一个抗麦二叉蚜的高粱品系Cargill 607E中，SbPrx-1也因蚜虫取食而被诱导。这些数据表明，C4禾本科植物的这个基因组区域作为评估C4禾本科植物潜在抗虫性的标记可能很有价值。
