Gibberellic Acid Inhibits Browning , Enzyme Activity and Gene Expression of Phenylalanine Ammonia-Lyase in Phalaenopsis Leaf Explants
Gibberellic Acid Inhibits Browning , Enzyme Activity and Gene Expression of Phenylalanine Ammonia-Lyase in Phalaenopsis Leaf Explants
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发表时间：
2009
期刊：
影响因子：
3.7
通讯作者：
Wenling Zhou;Rufang Tan;Chuanjun Xu;Yanyan Lai;Dongyin Chen;Ling Li
中科院分区：
文献类型：
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作者：
Wenling Zhou;Rufang Tan;Chuanjun Xu;Yanyan Lai;Dongyin Chen;Ling Li
研究了赤霉素酸（GA3）对蝴蝶兰（Doritaenopsis Queen Bee“Red Sky”）叶片组织培养过程中褐变、苯氨裂解酶（PAL, EC 4.3.1.5）酶活性和基因表达的影响。分别用0（对照）、1、5、10、25、30、50和70 mg L的GA3处理外植体。25 mg L GA3处理的外植体褐化率和单宁含量远低于培养4 d以上的对照外植体。赤霉素生物合成抑制剂多效唑（Paclobutrazol， PBZ）在5 mg L浓度下可提高赤霉素褐变率，表明内源性GA3抑制赤霉素褐变。GA3处理降低了PAL活性和PAL基因表达，PBZ处理提高了PAL基因表达。上述结果表明，GA3通过调控蝴蝶兰组织培养中PAL基因表达和酶活性，参与了叶片外植体褐化。_____________________________________________________________________________________________________________
The effects of gibberellic acid (GA3) on browning, enzyme activity and gene expression of phenylanine ammonia lyase (PAL, EC 4.3.1.5) in Phalaenopsis (Doritaenopsis Queen Bee “Red Sky”) leaf explants during tissue culture were investigated. GA3 at 0 (control), 1, 5, 10, 25, 30, 50 and 70 mg L were used to treat the explants. The percentage browning and tannin content of explants treated with 25 mg L GA3 were far lower than of control explants cultured for more than 4 days. Paclobutrazol (PBZ), a gibberellin biosynthetic inhibitor, at 5 mg L, increased the browning percentage, which implied that it was endogenous GA3 that repressed browning. PAL activity and PAL gene expression were reduced by GA3 treatment but were increased by treatment with PBZ. These results indicate that GA3 is responsible for the browning of leaf explants through the regulation of PAL gene expression and enzyme activity in Phalaenopsis tissue culture. _____________________________________________________________________________________________________________