黄花梨及其绿皮芽变绿黄花梨果实木质素、总酚含量及相关酶活性差异分析

Differences of lignin and total phenol compound content and the activities of enzymes in Huanghua pear and its mutant(Pyrus pyrifolia Nakai)

为了探索黄花梨及其绿皮芽变绿黄花梨在盛花后6~10周(WAFB)果皮色泽差异的原因,本研究测定了黄花梨和绿黄花梨果皮果肉的木质素、总酚类含量及其POD、PPO、PAL、4CL和CAD活性。结果表明:黄花梨和绿黄花梨在8 WAFB时果皮色泽出现差异,且褐色逐渐加深;在6~10 WAFB时黄花梨和绿黄花梨果皮果肉的木质素含量变化趋势一致、不断上升,且黄花梨高于绿黄花梨;黄花梨和绿黄花梨果皮果肉的总酚类含量变化趋势相似,均表现为先降低后升高再降低的特点,且黄花梨总体上高于绿黄花梨;黄花梨果皮POD、PAL、4CL和CAD活性均高于绿黄花梨,而PPO活性与绿黄花梨接近。黄花梨和绿黄花梨果皮的木质素和总酚类含量变化趋势,与出现色泽差异的步调基本一致,推测木质素等酚类参与了褐色果皮的形成。

To explore the differences of skin color between Huanghua pear and its bud mutant Lühuanghua pear,and to provide an experimental basis for finding the metabolites from russet sand pear during 6-10 weeks after full blossom(WAFB),the content of lignin and total phenol compound in skin and pulp and the activities of peroxidase(POD),polyphenol oxidase(PPO),phenylalanine ammonia-lyase(PAL),4-coumarate: coenzyme A ligase(4 CL) and cinnamyl alcohol dehydrogenase(CAD) were measured. The result showed that the 8 WAFB was the critical period of skin color changing for Huanghua pear and Lühuanghua pear,skin color changing appeared and then deepened to brown gradually. During 6-10 WAFB,the lignin content in skin and pulp was increased both in Huanghua pear and Lühuanghua pear,but Huanghua pear had a higher lignin content than Lühuanghua pear. The content of phenolic compound had similar trend in skin and pulp of Huanghua pear and Lühuanghua pear,which were decreased first,then increased and finally decreased again. The total phenol compound content in skin and pulp were higher in Huanghua pear than Lühuanghua pear. The activities of POD,PAL,4 CL and CAD in skin were higher in Huanghua pear than Lühuanghua pear,and the activity of PPO in Huanghua pear was close to that in Lühuanghua pear. The main results showed that a significant skin color changing appeared in 8 WAFB in Huanghua pear and Lühuanghua pear.The lignin content and total phenol compound content had the same trend,which was coincident with the color changing in Huanghua pear and Lühuanghua pear. Therefore,it's probable that the lignin and total phenol compound in skin were involved in the russet color formation in sand pear.