Clavibacter michiganensis Downregulates Photosynthesis and Modifies Monolignols Metabolism Revealing a Crosstalk with Tomato Immune Responses

The gram-positive pathogenic bacterium Clavibacter michiganensis subsp. (Cmm) causes bacterial canker disease in tomato, affecting crop yield and fruit quality. To understand how tomato plants respond, the dynamic expression profile of host genes was analyzed upon Cmm infection. Symptoms became evident from third day. As progressed, population increased planta, reaching highest level at six days remained constant till twelfth day post inoculation. These two time points were selected for transcriptomics. A progressive down-regulation key encoding components photosynthetic apparatus observed. Two temporally separated defense responses observed, which to an extent interdependent. During primary response, phenylpropanoid pathway diverted towards synthesis monolignols away S-lignin. In dicots, lignin polymers mainly consist G- S-units, playing important role defense. twist G-lignin enrichment is consistent with previous findings, highlighting a response generate early protective barrier achieve tight interplay between recomposition mechanism. Upon progression infection, temporal deactivation phenylpropanoids coincided upregulation that belong secondary mechanism, supporting elegant reprogramming transcriptome establish robust suppress pathogen invasion. This high-throughput analysis reveals reorganization plant mechanisms infection implement array barriers preventing invasion spread.