盐胁迫条件下玉米萜类合成相关基因的表达分析

萜类是植物生长发育中具有重要作用的次级代谢产物，某些萜类可被生物和非生物胁迫诱导产生。用200 mmol/L NaCl溶液处理商用玉米品种天塔五号（F1）及其父母本三叶期幼苗，qRT-PCR结果发现萜类合成途径中的萜烯合酶基因2（terpene synthase 2, TPS2）、萜烯合酶基因3（terpene synthase 3, TPS3）、牻牛儿基牻牛儿基焦磷酸合成酶基因4（geranylgeranyl diphosphate synthase 4, GGPS4）在三组材料中表达量随胁迫时间延长均先上调再下调，且F1表达量显著高于亲本。F1自交F2代耐盐性及基因表达情况分析表明，F2代中三个基因表达仍与耐盐性呈正相关。对盐胁迫条件下总类胡萝卜素及各成分含量、生物量、光合指标、叶绿素和脯氨酸含量进行测定，发现F1耐盐能力明显优于亲本，表明 TPS2、TPS3、GGPS4 基因高水平表达与F1发挥耐盐优势、抵御逆境胁迫有一定相关性。

The Expression and Analysis of Terpene Synthesis Related Genes in Maize under the Condition of Salt Stress

Terpenes are important secondary metabolites that play a vital role in plant growth and development, some of which can be induced in response to biotic and abiotic stresses. The Tianta 5(F1) and its parent lines were treated with 200 mmol/L NaCl when they were at three-leaf stage. The qRT-PCR results showed the expression level of terpene synthase 2(TPS2), terpene synthase 3(TPS3) and geranylgeranyl diphosphate synthase 4(GGPS4) genes were up-regulated then down-regulated of all lines under salt stress, and the expression level of F1 was much higher than its parent lines.The expression level of three genes was positively correlated with the salt resistance of F2.The content and composition of carotenoids, biomass, photosynthetic indicators, content of chlorophyll and free proline were detected. The results showed that the salt tolerance of F1 was significantly higher than the parent lines. In conclusion, the high expression of TPS2, TPS3 and GGPS4 has a certain correlation with the resistance of salt and other abiotic stress of F1.