茉莉酸甲酯和水杨酸对丹参幼苗中蔗糖代谢和酚酸类物质积累的影响

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

以丹参幼苗为材料,研究了茉莉酸甲酯(MeJA)和水杨酸(SA)对其地上地下部分蔗糖代谢和根系中酚酸类物质积累的影响.结果显示:(1)外源施用MeJA能够显著增强幼苗叶片和根中酸性蔗糖转化酶活性,促进蔗糖降解,减少根系中蔗糖含量;同时根中丹参素(来源于酪氨酸-衍生物支路)、原儿茶酸(类苯丙烷支路的中间产物)、咖啡酸(来源于类苯丙烷支路)、迷迭香酸(来源于类苯丙烷支路和酪氨酸-衍生物支路)、丹酚酸B(丹参素、咖啡酸、迷迭香酸的衍生物)以及总酚酸含量均显著增加.(2)外施SA可显著降低幼苗叶片和根中酸性蔗糖转化酶活性及叶片中性蔗糖转化酶活性,抑制蔗糖降解,显著增加地上部分蔗糖含量,根中蔗糖含量和对照相比差异不显著;同时根中丹参素含量减少,但原儿茶酸、咖啡酸以及迷迭香酸含量增加,丹酚酸B和总酚酸类物质含量与对照相比差异不显著.因此推测,植物中蔗糖代谢影响丹参素合成的酪氨酸-衍生物支路,而不影响原儿茶酸、咖啡酸及迷迭香酸等合成的类苯丙烷支路.

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.