Gibberellin producing Neosartorya sp. CC8 reprograms Chinese cabbage to higher growth

Gibberellins production by soil fungi received little attention, although substantial work has been carried out on other growth promoting aspects of soil borne fungi. We investigated gibberellins production and growth promoting capacity of a novel fungal strain of Neosartorya, which was isolated from the roots of Chinese cabbage (Bassica rapa L. ssp. pekinensis). Fungal culture filtrates (CF) obtained from pure cultures of 16 endophytic fungi were bioassayed on Waito-C, in order to investigate plant growth promoting capacity of these fungi. The fungal isolate CC-8 induced maximum shoot length of Waito-C (13.0 cm) as compared to control treatments. In a separate experiment, the CF of fungus CC-8 significantly promoted plant length and biomass of Chinese cabbage. The fungal CF also increased endogenous bioactive GA1 and GA4 contents of Chinese cabbage. Gibberellin analysis of CF of CC-8 showed presence of both physiologically active and non active gibberellins in higher concentrations (GA1, 1.42 ng/ml; GA3, 5.93 ng/ml; GA4, 11.36 ng/ml; GA7, 3.25 ng/ml; GA9, 0.79 ng/ml; GA15, 1.18 ng/ml). The culture filtrate of CC-8 produced higher amounts of GA3, GA4, GA7 and GA9 than wild type Fusarium fujikuroi, a well known gibberellins producing fungus. The fungal isolate CC-8 was later identified as a new strain of Neosartorya species on the basis of traditional and advance molecular techniques.

► In this study we reported a new strain of Neosartorya as plant growth promoting endophytic fungus. ► This fungal strain was found secreting gibberellins, and GA production was casual factor of plant growth promotion. ► GA production was reported for the first time for Neosartorya.