Effects of Salicylic Acid and Methyl Jasmonate on Sucrose Metabolism and Phenolic Compounds Accumulation in Salvia miltiorrhiza Bunge Seedlings

Salvia miltiorrhiza seedling was used as material in the experiment to investigate accumulation of phenolic compounds and sucrose metabolism of the seedling responding to salicylic acid(SA) and methyl jasmonate(MeJA) foliar application.The results showed that the MeJA treatment promoted activity of acid invertase(pH 5.0) in both the leaves and roots and accelerated sucrose hydrolysis in the seedlings,thus resulted in the decrease of sucrose content in the roots;while tanshensu sodium(which is biosynthesized through tyrosine-derived pathway),protocatechuic acid and caffeic acid(all the two compounds were produced through phenylpropanoid pathway),rosmarinic acid(which is produced through both tyrosine-derived pathway and phenylpropanoid pathway),salvianolic acid B(which is generated from tanshensu,caffeic acid and rosmarinic acid) as well as total polyphenol contents in the roots were significantly increased too.However,the activity of acid invertase in both the leaves and roots and the activity of neutral invertase in the leaves were decreased by the SA treatment to the seedlings,thus inhibited sucrose hydrolysis and significantly increased sucrose content in the shoots.The content of sucrose in the roots did not change significantly;Meantime,tanshensu sodium production was decreased,whereas the contents of protocatechuic acid,caffeic acid and rosmarinic acid in roots were significantly increased,the contents of salvianolic acid B and total polyphenol exhibited no significant changes.This indicates that sucrose metabolism correlate with tanshensu biosynthesis via tyrosine-derived pathway,but rarely influence protocatechuic acid,caffeic acid and rosmarinic acid production through phenylpropanoid pathway in the plant.