光照强度对葡萄愈伤组织形成过程中相关酶活性和基因表达的影响

Effects of light intensity on associated enzyme activity and gene expression during callus formation of Vitis vinifera

摘要:

文中分析了葡萄愈伤组织诱导和继代培养的最佳光照强度并探索葡萄愈伤组织褐变的机理。以金手指葡萄的幼嫩茎段为材料，设置0、500、1 000、1 500、2 000、2 500、3 000和4 000 Lx等8个光照强度，研究不同光照强度对葡萄愈伤组织的诱导率、褐化率及相关酶活性和基因表达的影响。结果表明，在0、500、1 000和1 500 Lx光照强度处理下，愈伤组织的诱导率均达到92%以上，显著高于其他处理 (P<0.05)，其中1 000和1 500 Lx光照强度处理愈伤组织及其继代培养的生长势良好且褐化程度较轻；绿原酸、咖啡酸、对羟基苯甲酸和香豆酸与葡萄愈伤组织褐变关系密切，其中绿原酸的含量与褐化程度呈显著正相关 (P<0.05）；POD和PPO酶活性与褐化率呈极显著负相关 (P<0.01)；POD、PPO和PAL酶基因的表达量与褐化率呈显著 (P<0.05) 或极显著 (P<0.01) 正相关。因此，葡萄愈伤组织诱导和继代培养适宜的光照强度为1 000?1 500 Lx，光照强度过高或过低对其正常的生理生长都有较大负面影响。

Abstract:

We analyzed the best light intensity for callus induction and maintenance in Vitis vinifera and explored the mechanism of grape callus browning. Tender stem segments?of grape cultivar “gold finger” were used to study the effects of different light intensities (0, 500, 1 000, 1 500, 2 000, 2 500, 3 000 and 4 000 Lx) on the induction rate, browning rate and associated enzyme activity and gene expression during Vitis vinifera callus formation. The callus induction rate under 0, 500, 1 000 and 1 500 Lx was more than 92%, significantly higher than in other treatments (P < 0.05). A lower browning rate and better callus growth were also observed during subculture under 1 000 and 1 500 Lx treatments. We found that chlorogenic acid, caffeic acid, p-hydroxybenzoic acid and coumaric acid contents were correlated with the browning rate of callus, among which chlorogenic acid content was positively correlated with the browning rate (P < 0.05). Peroxidase (POD) and polyphenol oxidase (PPO) activities were negatively correlated with the browning rate of callus (P < 0.01). The POD, PPO and phenylalanine ammonialyase (PAL) expression levels were positively correlated with the browning rate at P < 0.05 or P < 0.01. An appropriate light intensity for the tissue culture of Vitis vinifera was 1 000?1 500 Lx, higher or lower light intensities significantly impaired normal callus growth.