An influence of physiologically active compounds on biochemical changes during ripening of fleshy fruits and their resistance to infection

During ripening and keeping, the fruits are injured with different intensity. A softening of tissues during ripening is effect of polygalacturonase activity. The investigation of ethylene biosynthesis simultaneously with detection of activity of protein inhibitor of polygalacturonase (PIPG) under the influence of treatments by physiologically active compounds permit to obtain the data about molecular mechanisms of ripening and plant immunity, and also to propose the biotechnological methods of optimization of these function. The authors studied the change of the intensity of ethylene biosynthesis and accumulation of PIPG in apple fruits ( Malus domestica Borkh.) of early and late varieties (Antonovka common, Moskovskoe late, Moskovskoe green, Studencheskoe, Mantuanskoe) and banana ( Musa acuminata Colla) during the ripening and under the action of growth regulator and inhibitor of ethylene biosynthesis. The authors estimated also the speed of ripening and the degree of fruits resistance to 11 species of microorganisms, which were pathogenic and nonpathogenic for studied cultures. The treatment of the fruits by ethacide, degradading in fruits with ethylene production, results in intensified accumulation of 1-aminocyclopropane-1-carboxylic acid and release of ethylene, which causes acceleration in fruits ripening. The treatment by astaxanthin retards a process of ripening. The treatment by aminoethoxyvinylglycine, aminooxyacetic acid and CoCl 2 inhibits ethylene biosynthesis in fruits and slows down their ripening. The delay in fruits ripening is accompanied by increasing in PIPG content and also by accumulation of oligouronids, which stimulate the reactions, prevented the development of diseases.