Lipid signaling in plant defense: Unraveling sorghum-aphid interactions

Lipids form the building blocks of the cell membrane that shares a prime role in enhancing plant defense against a wide range of biotic and abiotic stresses. Sorghum, the world’s fifth most important cereal crop, suffers severe yield losses by attack from the sugarcane aphid (SCA; Melanaphis sacchari). Here, we employed electrospray ionization mass spectrometry (ESI-MS) technique to unravel the lipidome profiling in SCA-resistant (SC265) and susceptible (SC1345) sorghum lines at early (1, 48 h) and late (7 dpi) time-points before and after SCA infestation. As opposed to the susceptible line, SCA feeding drastically reduced the overall lipids in the SCA-resistant sorghum line. RNA-sequencing revealed that a Patatin-like protein (SbPLP) gene with putative lipid acyl hydrolase activity was induced significantly in the resistant line (SC265) at 7 dpi. Furthermore, Virus Induced Gene Silencing (VIGS) was utilized to knockdown the transcript to validate its role in sorghum resistance to SCA. Our aphid bioassays show that SbPLP-silenced plants supported higher SCA counts compared to the control plants. Comparison of SCA feeding behavior using Electrical Penetration Graph (EPG) technique revealed that aphids spent significantly more time in the sieve elements of the SbPLP-silenced plants compared to the control plants. The present study would help us to unravel the role of lipids in modulating sorghum defense against aphids and our result provide valuable perspectives on harnessing plant lipid profiles for biotechnological applications and agricultural improvement.