Hydrogen sulfide promoted cell differentiation, antioxidant ability, and flavonoids accumulation in Ginkgo biloba L. suspension cells

Hydrogen sulfide (H2S) as the third gasotransmitter could regulate many physiological processes such as growth and stress responses in plants. However, few studies focused on H2S affecting cell differentiation and secondary metabolism of suspension cells. In this study, we investigated the impact of sodium hydrogen sulfide (NaHS) doses (0, 0.5, 1.0, 3.0 mM) as H2S-donor at different time points on cell differentiation, antioxidant capacity, and accumulation of flavonoids (Fla) and terpene lactones (Lac) in Ginkgo biloba L. suspension cells. Results showed that distinct asymmetric division with a large and a small cell appeared in suspension cells under three NaHS treatments. Especially, the cells became enlarged, rounded and compact, and resembled embryonic cell mass in treated 3.0 mM. The 0.5 and 1.0 mM NaHS treatments efficiently promoted the growth, enhanced the enzyme activities such as SOD, POD, PAL, and 4CL (4-coumarate-Coenzyme A ligase), etc., as well as increased the levels of chlorophyll, carotenoid, AsA (Ascorbic acid), and total Fla or Lac in suspension cells. The best treatment was 1.0 mM treated for 4 or 7 days, and total Fla and Lac increased by 18.7% (4d) and 76.1% (7d) compared with the control, respectively. The high dose (3.0 mM) of NaHS treatment for 7 days restrained cells growth by decreasing photosynthetic pigments levels, and enhanced lipid peroxidation by increasing MDA content (141.5%) and the relative electrical conductivity levels (82.9%) compared to the control. High-dose NaHS also inhibited the above enzyme activities and total Flc and Lac accumulations. However, short-term 3.0 mM NaHS treatment (1d) could increase total Fla and Lac levels. This study provided new insights into the cell differentiation and the production of secondary metabolites in cell culture of G. biloba.