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作 者 ：马泓思1；潘亚婕1；王艳1；尹静1*；詹亚光1,2；赵微1；张梦岩1；梁　甜1

期 刊 ：植物研究 2015年 35卷 1期 页码：117-126

关键词：白桦；悬浮培养；MeJA；三萜化合物；Ca2+；

Keywords:BetulaplatyphyllaSuk., suspensionculture, MeJA, triterpenoid, Ca2+,

摘 要 ：以白桦细胞为试材，通过在悬浮培养第七天进行MeJA、CaCl₂及其互作处理，研究Ca²⁺在MeJA诱导白桦三萜合成中的作用。结果表明，MeJA处理后显著促进白桦细胞中总三萜和齐墩果酸的合成，分别于48 h达到最高积累量46.90和1.31 mg·g^-1。MeJA+EGTA和MeJA+LaCl₃·7H₂O处理，均降低了MeJA对三萜合成的促进作用，仍显著高于对照。抗逆酶结果显示，CaCl₂和MeJA+CaCl₂处理均不同程度的提高了CAT、PAL和APX的活性，而SOD的活性则受到Ca²⁺的抑制；两种钙离子抑制剂加入后显著影响抗逆酶的活性。MeJA处理早期（2 h），三萜途径各关键酶基因FPS、SS、SE、BPW、BPY显著上调表达。MeJA+LaCl₃·7H₂O处理早期（2 h）除BPW降低外，BPY、BPX2、SS和SE表达量均高于MeJA单独处理；而同MeJA处理相比，MeJA+EGTA处理2 h，BPW、BPX2、SS、SE和FPS表达量均下调。暗示Ca²⁺参与了MeJA诱导白桦防御系统启动和三萜物质合成，但两种Ca²⁺抑制剂EGTA和LaCl₃在三萜合成中的作用效果和机制存在差异。

Abstract:We investigated the role of Ca²⁺ in the MeJA-induced biosynthesis of triterpenoid by treating suspending cells of Betula platyphylla with CaCl₂, MeJA and combining with inhibitors of Ca²⁺. MeJA could promote the synthesis of total triterpenes and oleanolic acid in the cells significantly, which, respectively reached the peak of 46.90 and 1.31 mg·g^-1 after 48 hours’ treatment. The induction effect of MeJA decreased after treating by MeJA+EGTA and MeJA+LaCl₃·7H₂O. The accumulation amount of oleanolic acid were still higher than that of the control. By analyzing the activity of defense enzyme, the activities of CAT, PAL, APX were enhanced after treated by CaCl₂ and MeJA+CaCl₂, while the SOD was inhibited by Ca²⁺. After adding two inhibitors of Ca²⁺, all enzymes were effected significantly. The expression of key enzyme genes in the triterpene pathway such as FPS, SS, SE, BPW, BPY BPX2 was significantly upregulated after two hours’ MeJA treatment. The expression of BPW was reduced after two hours’ treating with MeJA+LaCl₃·7H₂O. The expression of BPY, BPX2, SS and SE regulated by MeJA+LaCl₃·7H₂O were higher than those treated by MeJA. Meanwhile the expression of BPW, BPX2, SS, SE and FPS were down-regulated at two hours after MeJA+EGTA treatment compared with MeJA treatment. Therefore, Ca²⁺ played a role in triterpenoid biosynthesis induced by MeJA, but two Ca²⁺ inhibitors had different effect and mechanism in triterpenoid biosynthesis.

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