The cellulolytic activity and symbiotic potential of dark septate endophytic fungus Phialocephala fortinii to promote non-mycorrhizal plants growth

Abstract

The endophytic fungi have attracted much attention to investigating their ability to degrade cellulose and promote plant growth as double functional roles. The objective of this study was to investigate the cellulase activity and the ability of dark septate endophytic fungus (DSE) Phialocephala fortinii to promote non-mycorrhizal plants. This study consisted of carboxy-methylcellulose degradation activity of DSE isolates, cellulase activity, and the effect of cellulolytic DSE to promote non-mycorrhizal plants growth assays. The results showed P. fortinii III.Pi.I8 had the largest cellulolytic index than P. fortinii CKG.II.10.1 and P. eryngii for 7 days of incubation time. The cellulase activity pattern of all P. fortinii isolates was rather similar to P. eryngii for the incubation time of 7 to 35 days. Phialocephala fortinii III.Pi.I8, CKG.II.10.1, and CKG.I.11 increased the growth of Brassica oleracea var. capitata by 7.63, 92.5, and 47.7%, and Spinacia oleracea by 58.5, 283, and 303%, respectively, over to the control plant. Heavy colonization of P. fortinii occurred both in B. oleracea var. capitata and S. oleracea roots. This study proved that although P. fortinii has cellulase activity but did not cause disease symptoms in non-mycorrhizal plants so that it can potentially be multifunctional as cellulose decomposer and plant growth promoter.