AM真菌和紫穗槐苗互作早期宿主防御生理指标的响应特征

Response Characteristics of Physiological Defense Indexes of Host Plant at Early Stage of Arbuscular Mycorrhiza Development between Amorpha fruticosa and AM Fungi

在温室盆栽条件下研究AM真菌与紫穗槐互作早期宿主防御生理指标的响应特征。结果表明:在AM真菌侵染宿主植物早期阶段,根系保护酶瞬时激活,植保素类黄酮瞬时积累,而且接种根内球囊霉(GI)同接种摩西球囊霉(GM)处理相比保护酶活性和类黄酮含量变化相对较大。接种AM真菌处理MDA含量下降,尤其在紫穗槐出苗后25天,接种GI和GM处理MDA含量分别降低26.6%和25.8%。在保护酶失活的同时,几丁质诱导子降解产物GlcN和可溶性蛋白含量增加,而且产生一些新的蛋白,由此推测:几丁质诱导子的降解和新增蛋白的出现是调节植物防御反应允许建立互惠共生体的可能机制。

This article studied the response characteristics of protective enzymes and malondialdehyde（MDA） at the early stage of the development of arbuscular mycorrhizal between AM fungi and Amorpha fruticosa with a potting experiment in a greenhouse.The result showed that at the early stage of A.fruticosa infected with AM fungi,protective enzymes（PPO and POD） of the root system were transiently activated,along with an accumulation of flavonoid（a kind of phytoalexin）.The activities of protective enzymes and the flavonoid contents had greater increases in roots inoculated with GI（Glomus intraradices） than GM（Glomus mosseae）.Additionally,the contents of MDA decreased respectively 26.6% and 25.8% in GM-and GI-colonized plants in 25 d after the seed germination.With inactivation of the protective enzymes,contents of soluble protein and GlcN（Glucosamine） increased and some new proteins occurred,which indicated that the degradation of chitin and emergence of new proteins were potential mechanisms regulating the defense responses of host plants to develop mutually beneficial symbiosis.