Aberrant protein metabolism of tomato fruits infected by Clavibacter michiganensis pv. michiganense

Abstract

Summary An interrelated study of protein content, protease activity and total amino acid content of the fruit tissue of tomato cvs. “Pusa-Ruby” and “Punjab-Chuhara” was carried out during 24–120h of pathogenesis by Clavibacter michiganensis pv. michiganense. The trends of changes were the same in the fruit tissue of both cultivars but being slightly more pronounced in the cv. “Punjab-Chuhara”. At 48 h of pathogenesis there was a remarkable increase in the protein content of the bacterium-infected fruit over that of the healthy fruit. Concurrently protease activity and amount of total amino acids decreased. Later on, during 72–96 h of pathogenesis the amount of protein in diseased fruit was considerably lowered due to infection of the bacterium. At 72 h there was a higher protease activity and good amount of release of amino-acids in the infected fruits for their use up by the bacterium. The same trend, although at a lower degree persisted in 96 h infected fruit. However, in 120 h infected fruit there was a slight build up of protein with lesser protease activity and low release of amino acids.