不同株龄鲁菏红细根内生微生物群落变化特征

Characteristics of endophyte's community changes of Paeonia suffruticosa cv.Lu He Hong fine root in different plant ages

通过比较和分析不同株龄牡丹品种鲁菏红细根内生微生物群落结构、功能特征和网络关系,为探究株龄对牡丹内生微生物的影响和丰富牡丹内生微生物资源提供理论支持。本研究以株龄5(ART1)、12(ART2)、20(ART3)和30年(ART4)的鲁菏红细根(≤2 mm)为样品,基于16S rDNA和ITS高通量测序技术开展相关生物信息学分析。鲁菏红细根内生细菌和内生真菌样本97%序列分别被聚类为4 994个和1 485个运算分类单元(OTUs),株龄并不影响其内生微生物群落丰度和多样性。鲁菏红细根内生细菌以蓝细菌门(Cyanobacteria/Chloroplast)、变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)和酸杆菌门(Acidobacteria)为优势菌群,株龄超过20年后放线菌门和拟杆菌门显著减少,而酸杆菌门逐渐增加;鲁菏红细根内生真菌以子囊菌门(Ascomycota)占绝对优势,高达93.99%~96.14%。细根纤维素含量、POD和CAT活性随株龄的增加显著增加,且显著影响了内生细菌的群落结构。PICRUSt2和FUNGuild结果分别表明,内生细菌功能以新陈代谢为主,变化较小,株龄主要影响内生真菌的生态功能,在株龄12年以上的鲁菏红细根中病理营养型真菌显著增加,易感染病害。MENA分析显示株龄的增加加剧了内生微生物间的竞争关系,减弱其网络连接性。株龄引起牡丹细根内生微生物群落发生不同程度的变化,在株龄20年后有害内生微生物的增加,使其易发生病害,本研究结果可为预防大龄牡丹病害奠定理论基础。

By comparing and analyzing the endophyte's community structure,functional characteristics and network relationship in fine roots of tree peony variety Lu He Hong in different plant ages,this study provided theoretical support for exploring the effect of plant age on endophytes in tree peony and enriching endophytes resources in tree peony.In this study,the samples of Lu He Hong fine roots(≤2 mm) aged 5(ART1),12(ART2),20(ART3) and 30 years(ART4) were used to carry out relevant bioinformatics analysis based on 16S rDNA and ITS high-throughput sequencing technology.The results showed that 97% sequences of endophytic bacteria and endophytic fungi from Lu He Hong fine roots were clustered into 4 994 and 1 485 operational taxonomic units(OTUs),respectively,and the plant age did not affect the abundance and diversity of endophytic communities.Cyanobacteria/Chloroplast,Proteobacteria,Actinobacteria,Bacteroidetes,Acidobacteria were the dominant bacterial groups of Lu He Hong fine root endophytes.After more than 20 years of plant age,Actinobacteria and Bacteroidetes decreased significantly,while Acidobacteria gradually increased.Ascomycota was the dominant endophytic fungi in the fine roots of Lu He Hong,which reached 93.99%-96.14%.The fine root cellulose content,POD and CAT activity increased significantly with the increase of plant age,and significantly affected the community structure of endophytic bacteria.PICRUSt2 and FUNGuild results showed that the function of endophytic bacteria was mainly focused on metabolism with little change,and plant age mainly affected the ecological function of endophytic fungi.The pathotroph fungi increased significantly in Lu He Hong fine roots at plant age of more than 12 years,which was easy to be infected with diseases.MENA analysis showed that the increase of plant age aggravated the competition among endophytes and weakened their network connectivity.In conclusion,plant age causes different degrees of changes in the endophyte's community of tree peony fine roots,and the harmful endophytes increase after 20 years of plant age,which is prone to disease.The results of this study can lay a theoretical foundation for the preventing diseases of elder tree peony.