Unravelling the impact of cassava mosaic disease caused by Sri Lankan cassava mosaic virus infection: Insights from proteomics analysis of photosynthesis‐ and respiration‐related proteins

Abstract Sri Lankan cassava mosaic virus (SLCMV) poses a significant threat to global food security by affecting the production of cassava ( Manihot esculenta ) in South‐east Asia. It causes mosaic patterns on the leaves, disrupts photosynthesis and respiration, and alters carbohydrate accumulation in the tubers. This study aimed to identify proteins associated with cassava mosaic disease symptoms in three cassava cultivars: resistant (TMEB419), tolerant (Kasetsart 50, KU50) and susceptible (Rayong 11, R11) to SLCMV. These cultivars were inoculated with SLCMV using top‐cleft grafting and monitored at 21, 32 and 67 days post‐inoculation (dpi). The disease severity differed among the cultivars following SLCMV inoculation. Liquid chromatography–tandem mass spectrometry (LC–MS/MS)‐based proteomics analysis identified 541 differentially expressed proteins (DEPs), including photosynthesis‐ and respiration‐associated proteins such as RuBisCO large subunit‐binding protein α (LSBP), chlorophyll a ‐ b binding protein, photosystem I reaction centre subunit III (PSI‐F), glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and fructose‐bisphosphate aldolase (FBA). A protein–protein interaction network revealed interactions among PSI, PSII, cytochrome complex proteins and electron transporter proteins. Chlorophyll(ide) b reductase NYC1, upregulated in R11 (susceptible) at 21 and 32 dpi, interacted with chlorophyllase‐related proteins, suggesting that it has a role in altering chlorophyll metabolism. Reverse transcription‐quantitative PCR gene expression analysis confirmed upregulation of genes related to photosynthesis and respiration in KU50 and R11, predominantly at 21 or 32 dpi. These findings provide valuable insights into cassava responses to SLCMV infection, especially at the protein level and are key for developing resistant cultivars and effective disease management strategies in future research.