Herbivory By Greenbug (Schizaphis graminum) or Yellow Sugarcane Aphid (Sipha flava) Elicit Differential Transcriptional and Metabolic Responses in Switchgrass (Panicum virgatum)

Switchgrass (Panicum virgatum) is being grown as a biomass feedstock. While it is still in breeding development to improve its feedstock characteristics, land area devoted to switchgrass is continually increasing. As switchgrass production becomes wide spread, pressure from insect pests are likely to arise and could compromise biomass yields. Aphids are one such pest, and as recently observed with sorghum, the emergence of sugarcane aphid as a new pest can have a strong negative impacts on yields. Understanding how switchgrass responds to, resists, and/or tolerates aphid infestation will provide useful traits to include in breeding programs to limit the potential impact of aphid pests on biomass yields.

In this study, a stabilized population of switchgrass originally derived from random Summer ♀ x Kanlow ♂ crosses was used to query plant responses to infestation by two different aphid species, namely greenbug (GB; Schizaphis graminum) and yellow sugarcane aphid (YSA; Sipha flava). Plants were infested with one or the other aphid, and non-infested plants served as controls. Four pooled replicates of five individual plants each were collected at three time points (5, 10, and 15 days after infestation). Transcriptomes (RNA-Seq) and metabolomes (LC-MS) were analyzed from control, GB-infested, and YSA-infested plants in order to identify common and species-specific responses to aphid infestation in switchgrass. Data indicates both common and unique plant responses to these individual pests.