盐胁迫对加工番茄叶片番茄红素β-环化酶基因表达量的影响

Effect of Salt Stress on Expression of Lycopene Cyclase Gene in Processing Tomato Leaves

以加工番茄品种"石红305"、"里格尔87-5"以及"LA2711"为试材,采用半定量RT-PCR法初步检测了不同浓度盐胁迫下加工番茄叶片中番茄红素β?环化酶(Lyc-β)基因的表达水平,以期探索盐胁迫对加工番茄类胡萝卜素代谢影响的分子机理。结果表明:一定范围的盐浓度可以上调或下调Lyc-β基因的表达,且随着盐浓度的增加,不同加工番茄品种叶片中Lyc-β基因的表达量呈现不均一变化,这可能与品种的基因型以及耐盐性有关;利用HPLC方法对相应叶片中β?胡萝卜素含量进行测定后发现,Lyc-β基因的表达与β?胡萝卜素含量的变化相符,这也在一定程度上说明盐胁迫可通过调控Lyc-β基因的表达量来影响β?胡萝卜素的代谢。

Taking three tomato cultivars ＇ Shihong305 ＇, ＇ Ligeer 87 -5 ＇ and ＇ LA2711 ＇ as material, the expression of lycopene cyclase gene （Lyc-β） of processing tomato leaves under the conditions of different salinity level was checked using semi-quantitative RT-PCR,in order to study the molecular mechanism of carotenoids synthesis in processing tomato leaves under salt stress. The results showed that the expression of Lyc-β gene could be up or down regulated at the certain range of salinity,it also found that different cultivars changed differently when the salinity level increased, which eould be related to the tomato＇s genotype and their ability of salt tolerance. HPLC was used for delermination of β-carotene content in corresponding leaves, the results illustrated that the change of Lyc-β gene expression was correlated with the change of β-carotene content in the leaves. This study further revealed that salt stress could affect the metabolism of β-carotene synthesis by regulating the expression of lycopene cyelase gene.