奉节脐橙果实苯丙氨酸解氨酶活性及其基因表达与果皮褐变的关系  

The Relationship between Activity and Gene Expression of Phenylalanine Ammonia-lyase and Peel Pitting in ‘Fengjie’ Navel Orange Fruits

作　　者：李正国[1] 高雪[1] 樊晶[1] 杨迎伍[1] 李道高[2] Angelos K.Kanellis 

机构地区：[1]重庆大学基因工程研究中心 [2]西南大学园艺园林学院 [3]Dept.of Pharmaceutical Sciences,Aristotle University of Thessaloniki,54124 Thessaloniki,Greece

出　　处：《植物生理与分子生物学学报》2006年第3期381-386,共6页Journal Of Plant Physiology and Molecular Biology

基　　金：重庆市科委攻关项目(No.03-8001);中国-希腊政府间科技合作项目(No.2003-63);教育部重点实验室访问基金项目;重庆大学研究生创新实践基地科技创新基金项目(No.200504Y1A0020110)资助。~~

摘　　要：柑橘果皮褐变严重影响果实的商品价值和耐贮性。以奉节脐橙(CitrussinensisOsbeck)果实为材料,通过采后常温、涂蜡、低温、机械损伤等处理研究了果实果皮褐变率、苯丙氨酸解氨酶(PAL)活性及PAL基因在果皮褐变过程中表达水平的变化。结果表明,涂蜡、损伤处理均极显著地提高果实的果皮褐变率,而低温贮藏可显著降低其发生率;贮藏期间各处理的PAL活性均呈上升趋势,损伤处理PAL活性显著高于对照。果实发生褐变或受到机械损伤后,PAL2、PAL6基因的表达均比对照明显增强。结果首次表明脐橙果实PAL活性变化以及PAL2基因的表达与果皮褐变具有非常密切的关系。Citrus fruit is prone to develope peel pitting during development and storage, which greatly decreases its fresh market value because of the deterioration of the peel. In the present study, we have examined the effect of different temperatures （15℃ and 4℃）, waxing and mechanical damage on the changes in the activity of phenylalanine ammonia-lyase （PAL） and the incidence of peel pitting in ＇Fengjie＇ navel orange （Citrus sinensis Osbeck） fruits. The expression levels of PAL2, PAL6 genes in the peel during the development of peel pitting have been investigated through semiquantitative PCR method. The incidence of peel pitting was greatly enhanced by waxing and mechanical damage and was decreased in lower temperatttre storage （4℃） （Fig. 1）. Waxing and mechanical damage might be the important factors inducing peel pitting and suitable low temperature could decrease the incidence of this disease. The PAL activity increased during the whole storage period in accordance with the development of this pitting （Fig. 2）. The expression levels of PAL2 and PAL6 genes in damaged peel were higher than those in healthy peel and the expression of PAL2 is much more higher than that of PAL6 （Figs. 4 and 5）. The results suggested that the enzyme activity of PAL, along with the expression of PAL2 gene are highly related to this peel pitting occurred on ‘Fengjie＇ navel orange fruits.

关 键 词：脐橙(Citrus SINENSIS Osbeck) 果皮褐变 苯丙氨酸解氨酶(PAL) PAL基因 表达 

分 类 号：S666.4[农业科学—果树学]