Effects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghum
Abstract Background Sugarcane aphid (Melanaphis sacchari) outbreaks in sorghum that were first reported in 2013 are now the most significant threat to this crop in all major sorghum production areas in the U.S. The outcomes of interactions between sugarcane aphid and sorghum and thus the severity of...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2018-10-01
|
| Series: | BMC Genomics |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s12864-018-5095-x |
| _version_ | 1818275525176590336 |
|---|---|
| author | Mahnaz Kiani Adrianna Szczepaniec |
| author_facet | Mahnaz Kiani Adrianna Szczepaniec |
| author_sort | Mahnaz Kiani |
| collection | DOAJ |
| description | Abstract Background Sugarcane aphid (Melanaphis sacchari) outbreaks in sorghum that were first reported in 2013 are now the most significant threat to this crop in all major sorghum production areas in the U.S. The outcomes of interactions between sugarcane aphid and sorghum and thus the severity of the outbreaks depend on sorghum genotype and potentially also on the phenology of sorghum. Mechanisms underlying these interactions are not known, however. Thus, the goal of this research was to characterize transcriptional changes in a commercially available resistant and a susceptible genotype of sorghum at 2- and 6-wk post-emergence exposed to M. sacchari herbivory. The effects of sorghum age and genotype on the daily change in aphid densities were also evaluated in separate greenhouse experiments. Results A higher number of diffentially expressed genes (DEGs) was recovered from the 2-wk plants exposed to aphid herbivory compared to the 6-wk plants across genotypes. Further, gene ontology and pathway analysis indicated a suite of transcriptional changes in the resistant genotype that were weak or absent in the susceptible sorghum. Specifically, the aphid-resistant genotype exposed to M. sacchari up-regulated several genes involved in defense, which was particularly evident in the 2-wk plants that showed the most robust transcriptional responses. These transcriptional changes in the younger resistant sorghum were characterized by induction of hormone-signaling pathways, pathways coding for secondary metabolites, glutathion metabolism, and plant-pathogen interaction. Furthermore, the 2-wk resistant plants appeared to compensate for the effects of oxidative stress induced by sugarcane aphid herbivory with elevated expression of genes involved in detoxification. These transcriptional responses were reflected in the aphid population growth, which was significantly faster in the susceptible and older sorghum than in the resistant and younger plants. Conclusion This experiment provided the first insights into molecular mechanisms underlying lower population growth of M. sacchari on the resistant sorghum genotype. Further, it appears that the younger resistant sorghum was able to mount a robust defense response following aphid herbivory, which was much weaker in the older sorghum. Several pathways and specific genes provide specific clues into the mechanisms underlying host plant resistance to this invasive insect. |
| first_indexed | 2024-12-12T22:31:08Z |
| format | Article |
| id | doaj.art-e86a63bcbf1a4ec9aed907af66c568b2 |
| institution | Directory Open Access Journal |
| issn | 1471-2164 |
| language | English |
| last_indexed | 2024-12-12T22:31:08Z |
| publishDate | 2018-10-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Genomics |
| spelling | doaj.art-e86a63bcbf1a4ec9aed907af66c568b22022-12-22T00:09:37ZengBMCBMC Genomics1471-21642018-10-0119111810.1186/s12864-018-5095-xEffects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghumMahnaz Kiani0Adrianna Szczepaniec1Department of Entomology, Texas A&M AgriLife ResearchDepartment of Entomology, Texas A&M AgriLife ResearchAbstract Background Sugarcane aphid (Melanaphis sacchari) outbreaks in sorghum that were first reported in 2013 are now the most significant threat to this crop in all major sorghum production areas in the U.S. The outcomes of interactions between sugarcane aphid and sorghum and thus the severity of the outbreaks depend on sorghum genotype and potentially also on the phenology of sorghum. Mechanisms underlying these interactions are not known, however. Thus, the goal of this research was to characterize transcriptional changes in a commercially available resistant and a susceptible genotype of sorghum at 2- and 6-wk post-emergence exposed to M. sacchari herbivory. The effects of sorghum age and genotype on the daily change in aphid densities were also evaluated in separate greenhouse experiments. Results A higher number of diffentially expressed genes (DEGs) was recovered from the 2-wk plants exposed to aphid herbivory compared to the 6-wk plants across genotypes. Further, gene ontology and pathway analysis indicated a suite of transcriptional changes in the resistant genotype that were weak or absent in the susceptible sorghum. Specifically, the aphid-resistant genotype exposed to M. sacchari up-regulated several genes involved in defense, which was particularly evident in the 2-wk plants that showed the most robust transcriptional responses. These transcriptional changes in the younger resistant sorghum were characterized by induction of hormone-signaling pathways, pathways coding for secondary metabolites, glutathion metabolism, and plant-pathogen interaction. Furthermore, the 2-wk resistant plants appeared to compensate for the effects of oxidative stress induced by sugarcane aphid herbivory with elevated expression of genes involved in detoxification. These transcriptional responses were reflected in the aphid population growth, which was significantly faster in the susceptible and older sorghum than in the resistant and younger plants. Conclusion This experiment provided the first insights into molecular mechanisms underlying lower population growth of M. sacchari on the resistant sorghum genotype. Further, it appears that the younger resistant sorghum was able to mount a robust defense response following aphid herbivory, which was much weaker in the older sorghum. Several pathways and specific genes provide specific clues into the mechanisms underlying host plant resistance to this invasive insect.http://link.springer.com/article/10.1186/s12864-018-5095-xMelanaphis sacchariSorghum bicolorPlant-insect interactionRNA-seqPlant defenses |
| spellingShingle | Mahnaz Kiani Adrianna Szczepaniec Effects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghum BMC Genomics Melanaphis sacchari Sorghum bicolor Plant-insect interaction RNA-seq Plant defenses |
| title | Effects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghum |
| title_full | Effects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghum |
| title_fullStr | Effects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghum |
| title_full_unstemmed | Effects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghum |
| title_short | Effects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghum |
| title_sort | effects of sugarcane aphid herbivory on transcriptional responses of resistant and susceptible sorghum |
| topic | Melanaphis sacchari Sorghum bicolor Plant-insect interaction RNA-seq Plant defenses |
| url | http://link.springer.com/article/10.1186/s12864-018-5095-x |
| work_keys_str_mv | AT mahnazkiani effectsofsugarcaneaphidherbivoryontranscriptionalresponsesofresistantandsusceptiblesorghum AT adriannaszczepaniec effectsofsugarcaneaphidherbivoryontranscriptionalresponsesofresistantandsusceptiblesorghum |