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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Peanut and Small Grains Research Unit » Research » Publications at this Location » Publication #378743
Research Project: Genetic Mechanisms and Improvement of Insect Resistance in Wheat, Barley, and Sorghum

Location: Peanut and Small Grains Research Unit

Title: Elevated production of reactive oxygen species is related to host plant resistance to sugarcane aphid in sorghum

Author
item PANT, SHANKAR
item Huang, Yinghua

Submitted to: Plant Signaling and Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2020
Publication Date: 12/3/2020
Citation: Pant, S.R., Huang, Y. 2020. Elevated production of reactive oxygen species is related to host plant resistance to sugarcane aphid in sorghum. Plant Signaling and Behavior. http://doi.org/10.1080/15592324.2020.1849523.
DOI: https://doi.org/10.1080/15592324.2020.1849523

Interpretive Summary: Sugarcane aphid is a devastating insect pest that causes severe damage to sorghum plants and huge reduction in crop production in the U.S. and elsewhere. ARS scientists in Stillwater, Oklahoma conducted research on exploring molecular mechanisms of host plant resistance to sugarcane aphids recently. One of the research efforts was focused on examining production of reactive oxygen species (ROS) in plants that were attacking by the aphids and analyzing altered expression of related plant enzymes in response to aphid attack. In this report, their recent results showed that those aphid-induced reactive chemical species such as hydrogen peroxide (H2O2) were rapidly produced in the aphid-attacking plants. Significant increase in H2O2 accumulation was observed in resistant genotype at all time points surveyed as compared to susceptible plants. In addition, some related ROS enzymes were induced in aphid-challenged plants, leading to much higher expression in resistant plants compared to susceptible plants. On other hand, their research data exhibited aphid survival and fecundity were significantly inhibited in resistant plants when compared to susceptible plants. Taken together, those findings suggest that the elevated accumulation of H2O2 and the strong up-regulation of the antioxidant genes in sorghum may have contributed to host plant resistance to sugarcane aphid in resistant cultivar but the weak expression of those antioxidant genes in susceptible cultivar resulted in the failure of attempting defense against sugarcane aphid. In summary, the resulted information will contribute to a better understanding of the molecular mechanisms of host plant defense against sugarcane aphids.

Technical Abstract: Sugarcane aphid (Melanaphis sacchari) is a phloem feeding insect that severely affects growth and productivity of sorghum and other related crops. While growing body of knowledge is accumulating regarding plant and insect interactions, the role of reactive oxygen species (ROS) against aphid infestation in sorghum has not been established yet. Here, we demonstrated involvement of hydrogen peroxide (H2O2) and ROS detoxification enzymes in host plant resistance to sugarcane aphid in sorghum. We assessed the H2O2 accumulation and expression patterns of selected ROS scavenging enzymes including ascorbate peroxidase (APX), glutathione S transferase (GST), superoxide dismutase (SOD) and catalase (CAT)) in response to sugarcane aphid infestation at 3, 6, 9 and 12 days post infestation (dpi) in resistant (Tx2783) and susceptible (Tx7000) sorghum genotypes, respectively. Significant increase in H2O2 accumulation was observed in resistant genotype at all time points surveyed as compared to susceptible plants. Gene expression analysis also revealed that antioxidant genes were induced in both genotypes in responding to attack by sugarcane aphid, , but much stronger in the resistant line. Furthermore, aphid survival and fecundity were significantly inhibited in resistant plants compared to susceptible plants. Taken together, our results suggest that the elevated accumulation of H2O2 and the strong upregulation of the antioxidant genes in sorghum may have contributed to host plant resistance in Tx2783 against sugarcane aphid but the weak expression of those antioxidant genes in Tx7000 resulted in the failure of attempting defense against sugarcane aphid. This report also provides the experimental evidence for the role of ROS involvement in the early defensive response to attack by sugarcane aphid in sorghum.