Causes of blackening of infected spots of tomato fruits

ABSTRACT

Fruits of tomato infected with some pathogens especially Alternaria lycopersici showed substantial increases in levels of the aromatic amino-acids alpha amino butyric acid, tryptophane, tyrosine and phenylalanine when compared with the respective amino acids in the healthy plants of the same fruits. Also, total phenolic compounds and simple phenolic fractions namely salicylic acid, orcinol, gallic acid and syringic acid as well as indole acetic acid and indole acetonitrile were increased in the infected tissue. Blackening of the infected spots was connected with the substantial increases of these compounds, the formation and transformation of which are responsive to the invading pathogens and to resist the resulting diseases