D3377: Exploring resistance traits in perennial sorghum against sugarcane aphid

Perennial crops offer sustainable benefits over annual crops, providing both economic and environmental advantages. Sorghum (Sorghum bicolor) is a multipurpose crop used for foodgrains, fodder, and biofuel production. Sugarcane aphid (SCA; Melanaphis sacchari) is an economically important pest of sorghum, which can reduce yields up to 50% under high infestations. In this study, we investigated the natural variation in 50 perennial sorghum lines against SCA and identified SCA-resistant and SCA-susceptible perennial sorghum genotypes. Subsequently, we employed temporal transcriptomic analysis to identify defense-related pathways that interact together to reduce aphid growth in the resistant perennial sorghum genotype compared to the susceptible and wild-type (WT) plants. Interestingly, we found that the expression levels of genes related to the production of oxylipins were significantly higher in the SCA-resistant perennial sorghum genotype, in comparison to the SCA-susceptible and WT plants at early time points. Additionally, we observed higher expressions of genes related to the production of reactive oxygen species (ROS) in the SCA-resistant perennial sorghum genotype against SCA-susceptible perennial sorghum and the WT plants. Together, our findings suggest that the SCA-resistant sorghum perennial plants adapt to activate defense signaling mechanisms to alleviate SCA infestation, investing resources at the early stages of infestation. Identifying novel sources of perennial sorghum resistance to SCA will have a broader impact on future sorghum breeding programs.