光源或培养基成分对金花茶愈伤组织中DFR、LAR与PPO基因表达及总儿茶素含量的影响

Effects of light or medium components on gene expression of DFR, LAR and PPO and content of catechins in calli of Camellia nitidissima

关键词:  光,激素,碳源,苯丙氨酸,相关性分析

Key words:  light, hormone, carbon  source, PHE, correlation  analysis

摘要:

该文以富含儿茶素的金花茶愈伤组织为材料对不同光源、激素、碳源及苯丙氨酸处理30 d的愈伤组织中DFR表达量、LAR表达量、PPO表达量与总儿茶素含量的变化情况及四者两两之间的相关性进行了研究。结果表明：这四项检测项目均对以上处理有显著的响应；在以上各因素处理下，DFR与LAR的表达模式十分相似，其相关系数处在0.710-0.889之间；在不同碳源处理下，PPO表达量与总儿茶素含量的变化呈显著负相关关系，其相关系数为-0.696；在不同苯丙氨酸添加量处理下，DFR与LAR表达量变化均与总儿茶素含量变化呈显著正相关关系，其相关系数分别为0.786和0.564；适宜儿茶素离体生产的金花茶愈伤组织增殖配方为附加4 mg?L-1 6-BA、0.6 mg?L-1 2,4-D、30 g?L-1蔗糖与0.6608 g?L-1苯丙氨酸的MS固体培养基，其总儿茶素含量可达40.11 mg?g-1 (干重)。以上研究表明：与茶树相似，在金花茶中DFR与LAR在儿茶素代谢过程中密切相关；PPO表达量升高导致金花茶儿茶素损失；添加适宜浓度的苯丙氨酸作为前体物质是提高愈伤组织中总儿茶素含量的有效措施。

Abstract:

Studies on Camellia sinensis showed that light and medium components had significant effects on metabolism of catechins in materials cultured in vitro and that DFR gene, LAR gene and PPO gene all have close relationship with it. For the further study on molecular mechanism of metabolism of catechins and providing theoretical guidance for the deep development of catechins in Camellia nitidissima, calli rich in catechins were used as materials to study the variation of DFR gene expression, LAR gene expression, PPO gene expression and content of catechins and the correlation with each other in calli under different light source, hormones, carbon source or PHE treatments for 30 d. The results were as follows. All the above four detecting items reacted to in vitro treatments significantly. Under the above treatments, the expression pattern of DFR gene and LAR gene was very similar. The correlation coefficients between them two under these treatments were between 0.710 and 0.889. The correlation of PPO gene expression and content of catechins was significantly negative under different carbon source treatments and their correlation coefficient was -0.696. DFR gene expression was significantly positively related to the content of catechins under different PHE adding quantity treatments and the correlation coefficient was 0.786. LAR gene expression was also significantly positively related to the content of catechins under different PHE adding quantity treatments and the correlation coefficient was 0.564. MS solid medium supplented with 4 mg?L-1 6-BA, 0.6 mg?L-1 2,4-D, 30 g?L-1 sucrose and 0.6608 g?L-1 PHE was suitable for in vitro production of catechins. Content of catechins in calli cultured in this medium for 30 d was about 40.11 mg?g-1 (dry weight). Basing on the above research we concluded that similar to Camellia sinensis there was a close connection between DFR gene and LAR gene during metabolism of catechins in camellia nitidissima and that the increase of expression of PPO gene caused the loss of catechins in camellia nitidissima and that it was an effective way to add suitable amount of PHE for the increase of content of catechins in calli of camellia nitidissima. In this paper, it was the first time to study the variation of DFR gene expression, LAR gene expression, PPO gene expression and content of catechins and the correlation with each other in calli of Camellia nitidissima. The study was the base for the molecular mechanism of metabolism of catechins and provided theoretical guidance for in vitro production of catechins in Camellia nitidissima.