Reprogramming of sorghum proteome in response to sugarcane aphid infestation

Authors: GROVER, SAJJAN - University Of Nebraska; BETANCURT CARDONA, JUAN - University Of Nebraska; ZOGLI, PRINCE - University Of Nebraska; ALVAREZ, SOPHIE - University Of Nebraska; NALDRETT, MICHAEL - University Of Nebraska; Sattler, Scott; LOUIS, JOE - University Of Nebraska

Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/14/2022
Publication Date: 7/1/2022
Citation: Grover, S., Betancurt Cardona, J., Zogli, P., Alvarez, S., Naldrett, M., Sattler, S.E., Louis, J. 2022. Reprogramming of sorghum proteome in response to sugarcane aphid infestation. Plant Science. https://doi.org/10.1016/j.plantsci.2022.111289.
DOI: https://doi.org/10.1016/j.plantsci.2022.111289

Interpretive Summary: Sorghum is a major drought tolerant grain and forage crop for the U.S., but this crop is susceptible to insect pests. Sugarcane aphids are a key sucking-insect pest of sorghum, and they can cause significant yield losses. Plants have a complex network of signals, which they use to induce their chemical defenses to respond to insect attack. In this study, researchers from Lincoln, NE determined how sorghum proteins levels changed in response to aphid feeding through techniques referred to as proteomics. The sorghum SC265 line was used in the study because this line previously showed resistance to sugarcane aphids. A total of 4211 different proteins were identified from sorghum plants, and the levels of 158 proteins were altered compared to sorghum without aphids after 1 and 7 days of aphid feeding. This experiment showed that the levels of several plant defense-related proteins were decreased, but the levels of other plant defense- and signaling-related proteins were increased. To understand how these changes affect the aphids, a technique call electrical penetration graph (EPG) was used to examine aphid feeding behavior. EPG analyses revealed that that aphid spent significantly longer time feeding on the plants that were previously free of aphids than the ones that aphids had fed upon for either 1 day or 7-days. Overall, this study provided insights into the mechanisms, which are responsible for changes in defense related proteins. This research may result in new strategies to develop novel plant pathways for aphid resistance and new ways to identify aphid-resistant sorghum lines for plant breeding.

Technical Abstract: Sugarcane aphids (SCA; Melanaphis sacchari Zehntner) is a key piercing-sucking type pest of sorghum (Sorghum bicolor) which cause significant yield losses. While feeding on host plants, complex signaling networks are invoked from recognition of insect attack to induction of plant defenses. Consequently, these signaling networks lead to the production of insecticidal compounds or limited access to nutrients to insects. Previously, several studies are published on the transcriptomics analysis of sorghum in response to SCA infestation, but no information is available on the physiological changes of sorghum at proteome level. We used SCA resistant sorghum genotype SC265 for the global proteomics analysis after 1 and 7 days of SCA infestation using TMT-plex technique. Peptides matching a total of 4211 proteins were identified and 158 proteins were differentially expressed at day 1 and 7. Overall, proteome profiling of SC265 after SCA infestation at days 1 and 7 revealed the suppression of plant defense-related proteins and upregulation of plant defense and signaling-related proteins, respectively. The plants defense responses based on proteome data were validated using electrical penetration graph (EPG) technique to observe change in aphid feeding. EPG data analyses revealed that SCA spent significantly longer time in phloem phase on control plants compared to the corresponding1 day and 7-day infested sorghum plants. Overall, our study provides insights into underlying mechanisms that contribute to sorghum resistance to SCA.