Date of this Version
Ikuze, E., Grover, S., Puri, H., Sattler, S., Louis, J. 2022. Understanding the Role of CCoAOMT Gene in Sorghum Defense Against Sugarcane Aphids. Undergraduate Honors Thesis. University Of Nebraska-Lincoln.
Sorghum (Sorghum bicolor) is a beneficial, economic food crop cultivated around the globe. Since 2013, sorghum production in the United States has been negatively impacted by the attack of a piercing-sucking insect pest, sugarcane aphid (SCA; Melanaphis sacchari). Caffeoyl-coenzyme A O-methyltransferase (CCoAOMT), an enzyme that contributes to lignin modification, is suspected to increase/trigger sorghum resistance to SCA. This study used the sorghum reference line, RTx430 (wild-type), and two CCoAOMT gene overexpression lines, CCoAOMT9a and CCoAOMT28b, to assess the role of the CCoAOMT gene in sorghum resistance to SCA. Using the choice and no-choice assays, we have identified that the overexpression of CCoAOMT provided enhanced resistance to SCA compared to RTx430 plants. The Electrical Penetration Graph (EPG) analysis unveiled that the SCA spent significantly less time in the sieve element phase of CCoAOMT28b overexpression plants compared to RTx430 plants. Our study collectively demonstrates that the overexpression of the CCoAOMT gene provides enhanced resistance to SCA and deters the aphid from prolonged feeding from the sieve elements compared to the RTx430 plants.