MeJA对连翘叶片光合作用及次生代谢的影响

Effects of MeJA on Photosynthesis and Secondary Metabolism of Forsythia suspensa Leaves

为提高连翘的品质与产量,以连翘为试材,设置1、0.1、0.01 mmol/L 3个茉莉酸甲酯(MeJA)喷施浓度处理,以喷施清水处理为对照,研究叶面喷施不同浓度MeJA对连翘叶片光合特性、SPAD值、苯丙氨酸解氨酶(PAL)活性以及总黄酮、连翘苷、连翘酯苷A等次生代谢产物含量的影响。结果表明,不同浓度MeJA及喷施后不同时间对连翘叶片光合速率(Pn)、胞间CO2浓度(Ci)、气孔导度(Gs)和蒸腾速率(Tr)的影响不同,在一定时间内,MeJA浓度对Gs和Tr表现出低促高抑的作用;SPAD值随喷施后时间延长整体呈现先下降后上升的趋势;0.01 mmol/L MeJA喷施后2、6、24、48、72 h,连翘叶总黄酮含量分别较对照增加18.70%、34.13%、30.16%、40.57%、11.02%;0.01 mmol/L MeJA喷施后连翘苷含量在整体上较对照有一定的提升,但对连翘酯苷A的积累表现为抑制作用。喷施MeJA后2、6 h,3个喷施处理PAL活性均较对照增加,而在喷施后48 h,1、0.1、0.01 mmol/L MeJA喷施处理较对照分别降低15.88%、12.38%、12.56%。综上,0.01 mmol/L MeJA喷施后48 h可明显促进连翘叶次生代谢产物的积累。

In order to improve the quality and yield of F.suspensa,the F.suspensa leaves were sprayed with 1,0.1,and 0.01 mmol/L MeJA.Taking the spraying water treatment as a control,the effects of spraying different concentrations of MeJA on the photosynthetic characteristics,SPAD value,PAL activity and the content of secondary metabolites such as total flavonoids,forsythin,and forsythoside A of F.suspensa leaves were studied.The results showed that,different concentrations of MeJA and different treatment time had different effects on the Pn,Tr,Gs and Ci of F.suspensa leaves.For a certain period,MeJA showed inhibition of high concentration and promotion of low concentration on Gs and Tr.The SPAD value showed a trend of first declining and then rising with the extension of the time after spraying.At 2,6,24,48 and 72 hours 0.01 mmol/L MeJA treatment increased the accumulation of total flavonoids by 18.70%,34.13%,30.16%,40.57%,11.02%compared with the control,respectively.The 0.01 mmol/L MeJA treatment increased forsythin to a certain extent,but it showed an inhibitory effect on the accumulation of forsythoside A.At 2 h and 6 h after spraying MeJA,the PAL activity of each treatment increased compared with the control.At 48 h after spraying,the PAL activity of 1,0.1,0.01 mmol/L MeJA spraying treatments decreased by 15.88%,12.38%and 12.56%compared with the control,respectively.In summary,the accumulation of secondary metabolites of F.suspensa leaves at 48 h after spraying 0.01 mmol/L MeJA can be significantly increased.