Effects of LaCl3 on photosynthesis and the accumulation of tanshinones and salvianolic acids in Salvia miltiorrhiza seedlings

The effects of LaCl3 on the growth, photosynthetic gas-exchange characteristics, chlorophyll fluorescence, and the accumulation of tanshinones and salvianolic acids in Salvia miltiorrhiza seedlings were investigated. The results showed that the increase in photosynthesis induced by LaCl3 might be attributed to the enhanced stomatal conductance of the leaves and the increased level of the photochemical efficiency of PS II. The accumulation of tanshinone IIA and cryptotanshinone was markedly increased with the application of LaCl3 at 20 and 60 mg/L, while tanshinone I was only slightly increased. The content of salvianolic acid B was, however, decreased with the treatment of LaCl3 at 200 mg/L.