丛枝菌根真菌对刺槐幼苗机械损伤响应机制的初步研究

Basic Research on Response of Arbuscular Mycorrhizal Fungi to Robinia pseudoacacia L.Seedling with Mechanical Damage

通过对刺槐幼苗每隔3d剪去1片叶片造成持续机械损伤,测定了0～138h抗氧化酶活性变化及刺槐幼苗生长情况;同时使用孔径25μm尼龙网设置三室根箱隔网系统,测定了供体瞬时机械损伤后受体的抗氧化酶活性的持续变化,探讨接种丛枝菌根真菌刺槐幼苗对持续及瞬时机械损伤后的响应机制,以及菌根菌丝桥对刺槐幼苗机械损伤信号的传递特征。结果表明：在持续机械损伤胁迫下,接种丛枝菌根真菌能够促进刺槐幼苗的根系生长、提高幼苗的成活率,接种丛枝菌根真菌的刺槐幼苗成活率及根系鲜重比对照分别增加15.38%和23.52%。瞬时机械损伤后0、48、90、114、138h刺槐幼苗的苯丙氨酸解氨酶（PAL）和过氧化物酶（POD）活性都呈现先增加后降低的趋势,均在90h达到最大值,并且菌根化幼苗的PAL和POD活性显著高于未菌根化幼苗。瞬时机械损伤后,菌根菌丝桥能够介导刺槐幼苗间相关信号的传递,从而引起菌根化受体刺槐幼苗的PAL和POD活性表现出与供体机械损伤幼苗相同的变化趋势。

In this study,we tested the response of black locust （Robinia pseudoacacia L.） with instantaneous and continuous mechanical damage to the arbuscular mycorrhizal （AM） fungi,and using three-partments system tested the role of common mycorrhizal networks （CMNs） in transmitting mechanical damage related signal between black locust seedlings.We set seedlings with a leaf cut and with a leaf cut every 3 days as the instantaneous and continuous mechanical damaged treatments,respectively,and tested the POD,PAL activities at 0-138 h and growth of the seedlings.Meanwhile,we used three-partments system with 25 μm nylon net to test POD and PAL activities of receptor plants after the donor plants suffered the instantaneous and continuous mechanical damage.The results showed that AM fungi can promote root growth and improve the ratio of transplanting survival of the seedlings with continuous mechanical damages.Suffering from instantaneous mechanical damage,the activities of L-phenylalanin ammo-nialyase （PAL） and peroxidase （POD） increased for 90 h and then decreased.Also,the PAL and POD activities of mycorrhizal seedlings were significantly higher than that of the non-mycorrhizal seedlings.And CMNs can transmit signals relating to mechanical damage,resulting in alteration of PAL and POD activities of donor plants.