Mycobacteria are hidden endophytes in the shoots of rock plant [Pogonatherum paniceum (Lam.) Hack.] (Poaceae)

Abstract

A mycobacterium was isolated from micropropagated Pogonatherum paniceum and identified as a close relative of Mycobacterium cookii. The endophyte diversity in the shoots of potted and micropropagated P. paniceum plants was studied by culture-independent techniques. Group- and strain-specific PCR demonstrated that the P. paniceum plants harboured the isolated Mycobacterium strain as a minority. Altogether 101 clones of the PCR products were sequenced. The shoots of potted P. paniceum plants harboured unculturable endophytes in the families Phyllobacteriaceae, Hyphomicrobiaceae, Sphingobacteriaceae, Enterobacteriaceae, Alcaligenaceae and Mycobacteriaceae. Among the unculturable Mycobacteriaceae strains related to Mycobacterium chubuense, M. poriferae, M. obuense, M. fortuitum, M. neoaurum, M. diernhoferi, M. intracellulare and M. cookii were identified. Three unique sequences that clustered with M. llatzarense and M. mucogenicum were identified in micropropagated plants. According to the results, the shoots and micropropagated tissues of rock plant are inhabited by mycobacteria, which should stimulate further studies on the diversity of unculturable mycobacteria in edible crop plants.