文冠果新梢发育过程酚类物质及相关酶活性变化特性

The Variation Characteristics of Phenolics Compound Content and Related Enzyme Activities during Development of Xanthoceras sorbifolia Bunge Shoots

以文冠果新梢为试验材料,通过分析文冠果新梢生长发育过程中的茎尖、茎段、叶片的多酚、类黄酮、单宁及相关酶(苯丙氨酸解氨酶、多酚氧化酶)活性,研究了文冠果新梢枝条发育过程中不同部位酚类物质的积累规律及相关酶活性的变化规律。结果显示:(1)文冠果新梢生长期内(4~9月)随着季节的变化,多酚、类黄酮、单宁等酚类物质含量总体上呈现上升趋势,新梢同一时期不同部位的多酚、类黄酮、单宁等酚类物质含量的分布情况相似,皆为:叶>茎尖>茎段。(2)文冠果不同发育时期的茎叶苯丙氨酸解氨酶活性大小为:新梢幼嫩茎段及相应叶片>半木质化茎段及相应叶片>木质化茎段及相应叶片;新梢叶片的多酚氧化酶活性显著高于茎段,茎尖的最低;文冠果叶片有着极强的抗氧化能力,对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的清除率最高可达98.13%。(3)在4月29日前后,文冠果新梢各部位多酚、类黄酮和单宁含量上升趋势有显著差异,各部位苯丙氨酸解氨酶活性最低,而多酚氧化酶活性最高,木质化程度不同的茎段DPPH·清除率均降至最低,表明4月29日是文冠果新梢生长期的一个重要过渡生长阶段。(4)文冠果的新梢多酚、类黄酮、单宁之间呈极显著正相关关系;多酚、类黄酮、单宁与DPPH·清除率存在极显著正相关关系,与多酚氧化酶活性呈显著正相关关系,与苯丙氨酸解氨酶活性之间相关性不显著。研究表明,酚类物质含量是影响文冠果无性繁殖的主要因素,酚类物质含量越低,文冠果的扦插、嫁接、组培的成活率越高;新梢多酚、类黄酮、单宁等酚类物质含量在生长初期最低,后随着新梢的生长呈现显著上升趋势;文冠果无性繁殖最好在新梢生长初期进行,最佳时间为4~5月中旬。

This paper is to study the regulation of accumulation of phenolics compound and the dynamic change law of related enzyme activities in different parts of shoots during development of Xanthoceras sorbifolia Bunge.We analyzed the content of polyphenols,flavonoids,tannins and the activities of related enzymes（phenylalanine ammonialyase polyphenol oxidase）in shoot tips,stems and leaves during the shoots＇ growth and development of X.sorbifolia by using shoots.The results showed that：（1）the contents ofpolyphenols,flavonoids and tannins presented a rising tendency with seasons in development of X.sorbifoliashoots;the contents of polyphenols,flavonoids and tannin were showing the following tendency：leaf〉stem tip〉stem.（2）The PAL activity of the development of X.sorbifolia new shoots is：young stem segments and corresponding leaves〉the semi-lignified stem segments and corresponding leaves〉the lignified stems and corresponding leaves.The PPO activity of leaves was significantly higher than that of stem segments,and the PPO activity of stem apex was the lowest.Leaves of X.sorbifolia had a strong antioxidant capacity;the highest scavenging rate of DPPH· was 98.13%.（3）Before and after April 29 th,there was a significant difference in the rising trend of polyphenols,flavonoids and tannins contents;PAL activity of all organs was the lowest and PPO activity was the highest;the DPPH· scavenging rate of stem segments with different degrees of lignification was reduced to the lowest;therefore,April 29 th was an important transitional growth stage of the shoot growth period.（4）Correlation analysis of X.sorbifolia new shoots revealed that there was a significant positive correlation between the contents of polyphenols,flavonoids and tannins;there was also a significant positive correlation between the contents of polyphenols,flavonoids,tannins and the scavenging capacities of DPPH·;there was also a positive correlation between the contents of polyphenols,flavonoids,tannins and PPO activity;however,there was not a positive correlation between the contents of polyphenols,flavonoids,tannins and PAL activity.The study suggests that the content of phenolics compound is the main factor affecting the vegetative propagation of X.sorbifolia;the lower the content of phenolics compound is,the higher the survival rate of cuttings,grafting and tissue culture.The content of phenolics compound such as polyphenols,flavonoids,and tannins is the lowest at the early stage of shoot growth,but the content of phenolics compound such as polyphenols,flavonoids and tannins increase significantly with the growth of new shoots.The vegetative propagation of X.sorbifoliais most suitable in the initial stage of shoots growth which the best time is from April to mid-May.