Plant growth regulators from fungus Alternaria porri

Abstract

The objective of this research was the isolation and identification of plant growth regulators from secondary metabolites of plant pathogenic fungi. Five plant pathogenic fungi (Alternaria porri, Trichoderma virens, Sclerotium rolfsii, Phytophthora parasitica and Trichoderma hazeanium) were selected for further plant growth regulators screening test. The crude ethyl acetate from the liquid culture of A. porri showed the highest inhibitory effect against lettuce seedling (Brassica pekinensis Rupr.). This crude extract was isolated to yield 5 compounds. They were altersolanol A (1), altersolanol B (2), altersolanol C (3) and two possible structural compounds (4 and 5). The structures of all compounds were determined on the basis of their NMR and also comparison with the literature data. The biological activity on plant growth regulators of lettuce and Echinochloa crus-galli Beauv. seedling, the major component 1showed completely inhibition of both plants at concentration of 1,000 ppm, while 2and 3showed close inhibitory activity to 1. However, 4and 5gave low activity.