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作 者 ：陈 雷,常 丽,曹福亮,汪贵斌*,董晓伟

期 刊 ：西北植物学报 2013年 4期 页码：755~762

关键词：银杏叶；黄酮类化合物；温度；干旱；酶活性；

Keywords:ginkgo leaves, flavonoid, temperature, soil moisture, enzyme activity,

摘 要 ：温度和土壤水分是影响银杏叶黄酮类化合物合成的重要环境因子,为了探讨温度和水分对银杏叶黄酮类化合物合成的影响,研究3个温度水平[5 ℃～15 ℃（T₁）、15 ℃～25 ℃（T₂）、25 ℃～35 ℃（T₃）]与3个土壤含水量水平[田间持水量的55%～60%（W₁）、田间持水量的40%～45%（W₂）、田间持水量的30%～35%（W₃）]对银杏叶黄酮类化合物含量、叶片黄酮类化合物合成上游的3个关键酶[苯丙氨酸解氨酶（PAL）、肉桂酸4-羟基化酶（C4H）、4-香豆酸辅酶A连接酶（4CL）]活性的影响。结果表明:（1）温度和干旱胁迫显著影响PAL、C4H和4CL的活性以及银杏叶类黄酮含量;随着环境胁迫的进行,3种酶活性普遍呈增加趋势,但不同酶之间也存在一定差异。（2）低温（T₁）与高温（T₃）胁迫均显著促进PAL活性;T₁则更加有利于叶片中C4H活性的增加;4CL活性的变化复杂,在胁迫处理的前期（14 d和28 d）,干旱条件是影响银杏叶4CL活性的主要因子,而到42 d之后,温度因子则成为主要影响因子。（3）银杏叶类黄酮含量均随着胁迫时间的推进而显著减少,在胁迫前期,干旱是影响类黄酮含量的主要因素,而到42 d之后,温度因子占主导作用。（4）相关分析表明,在温度和干旱胁迫下,PAL、C4H和4CL以及银杏叶生物量均与黄酮含量存在负相关关系;尽管环境胁迫促进了相关酶的活性,但银杏叶片中的类黄酮含量却呈下降趋势。

Abstract:Temperature and water are two important environmental factors that influence flavonoid synthesis in ginkgo (Ginkgo biloba) leaves.In this paper,we studied three temperature levels (T₁,5 ℃～15 ℃;T₂,15 ℃～25 ℃;and T₃,25 ℃～35 ℃,respectively) and three soil water content levels (30%～35%,40%～45% and 55%～60% of field water capacity,respectively) on flavonoid content and activities of L-phenylalnine ammonialyase (PAL),cinnamic acid 4-hydroxylase (C4H),and 4-coumarate-CoA ligase (4CL).Results showed that:(1)A significant difference for PAL,C4H,4CL and flavonoid was found in ginkgo leaves under the temperature and water stress (P＜0.05).These three enzyme activities increased with the stress.However,the results were still different in leaves for each enzyme activity.(2)High temperature (T₃) and low temperature (T₁) increased PAL,and the T₁ only increased C4H.For 4CL,in 14 and 28 day,water was the main factor to affect 4CL,but 42 day later,the temperature became the main factor.(3)The flavonoid in ginkgo leaves was decreased with stress (P＜0.05).Same as 4CL,water was the main factor in early days,but temperature was the main factor in later days.(4)From the analysis of relationship,PAL,C4H,4CL and ginkgo leaves biomass were negatively correlated with the flavonoid content.Although the temperature and water increased these enzyme activities,the flavonoid content in ginkgo leaves still decreased.

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