Enhancement of rutin production in Fagopyrum tataricum hairy root cultures with its endophytic fungal elicitors.

Tartary buckwheat (Fagopyrum tataricum) is a potentially important source of rutin, a natural bioactive flavonoid with antihyperglycemic, antioxidative, antihypertensive, and anti-inflammatory properties. This study examines the effects of endophytic fungi on rutin production in the hairy root cultures of F. tataricum. Without obvious changes in the appearance of the hairy roots, the exogenous fungal mycelia elicitors efficiently stimulated the hairy root growth and rutin biosynthesis, and the stimulation effect was mainly dependent on the mycelia elicitor species, as well as its treatment dose. Two endophytic fungal isolates Fat9 (Fusarium oxysporum) and Fat15 (Alternaria sp.) were screened as promising candidates for promoting F. tataricum hairy root growth and rutin production. With application of polysaccharide (PS) of endophyte Fat9 (200 mg/L), and PS of endophyte Fat15 (100 mg/L) to the hairy root cultures on day 25, the rutin yield was increased to 45.9 mg/L and 47.2 mg/L, respectively. That was about 3.1- to 3.2-fold in comparison with the control level of 14.6 mg/L. Moreover, the present study revealed that the accumulation of rutin resulted from the stimulation of the phenylpropanoid pathway by mycelia PS treatments. This may be an efficient strategy for enhancing rutin production in F. tataricum hairy root culture provided with its endophytic mycelia elicitors.