摘要
【目的】根际土壤细菌及真菌群落组成不仅受植物种类及植物生长时期等影响,外源基因的导入也可改变根际微生物群落组成。通过基因工程技术获得的转betA或转TaLEA基因小黑杨(populus simonii x p.nigra)能够提高甜菜碱或晚期胚胎富集蛋白的含量,进而增强转基因植物的抗旱耐盐性,PsnWRKY70是胁迫应答信号转导网络中的负调控因子,WRKY70干扰表达小黑杨的耐盐性显著高于对照株系。在明确了转betA、转TaLEA、转WRKY70小黑杨抗旱耐盐性的同时,开展转基因小黑杨根际土壤细菌、真菌群落组成分析,为其环境生态安全性评价提供参考。【方法】以2年生转TaLEA、betA、WRKY70基因小黑杨及对照野生型(WT)小黑杨根际土壤为试材,利用Illumina-Miseq高通量测序平台对根际土壤微生物进行16S rRNA和ITS测序分析,对根际土壤细菌和真菌群落丰富度和多样性变化、结构差异性、群落组成进行分析,了解转基因活动对小黑杨根际土壤微生物组成的影响。【结果】Alpha多样性分析显示,针对根际细菌群落组成,转betA小黑杨的Simpson指数显著低于WT小黑杨,而转WRKY70小黑杨观察物种数、Shannon及Simpson指数均显著低于WT小黑杨。针对根际真菌群落组成,3种转基因小黑杨的各项Alpha指数均显著低于WT小黑杨。韦恩图、主成分分析和聚类热图结果显示,在与WT小黑杨根际土壤细菌和真菌群落结构相似性上,转TaLEA小黑杨与WT小黑杨的群落差异较小,转betA小黑杨与转WRKY70小黑杨的群落组成更接近。基于属水平上的组成和丰度分析显示,转基因小黑杨根际土壤中,产黄杆菌属(Rhodanobacter)、芽单胞菌属(Gemmatimonas)等有益细菌相对丰度均有不同程度提高;而有益菌根真菌丝盖伞属(Inocybe)丰度在转TaLEA、转betA小黑杨中显著高于另外两个样品,小球孢盘菌属(Sphaerosporella)、粘滑菇属(Hebeloma)、蜡蘑属(Laccaria)丰度仅在转TaLEA小黑杨中显著提高;相反,亚隔孢壳属(Didymella)和背芽突霉属(Cadophora)等致病真菌丰度较WT小黑杨的降低85%以上。【结论】这些结果表明转基因活动可能利于植物生长并提升其抗逆性,但这些有益微生物是否发挥了重要作用并在实际环境中长期存在,仍需开展更多研究。
【Objective】The composition of bacterial and fungal communities in rhizosphere soil is not only affected by plant species and varying growth periods, but also by the introduction of foreign genes. The contents of betaine or late-embryogenesis-abundant proteins could be increased in transgenic poplar with betA and TaLEA genes, which were obtained by genetic engineering technology. Drought resistance and salt tolerance were also enhanced in these transgenic poplars. PsnWRKY70 is a negative regulator of the salt stress response signal transduction network. Salt tolerance of WRKY70 inhibitory expression line was significantly higher than that of the line wild type(WT). To clarify the drought resistance and salt tolerance of transgenic poplar with betA, TaLEA and WRKY70, the composition of rhizosphere soil bacterial and fungal communities of transgenic poplar was analyzed to provide a reference for its environmental and ecological security evaluation. 【Method】In this study, rhizosphere soil was collected from a two-year-old poplar with modified TaLEA, betA and WRKY70 genes, and WT plants were used as controls. The 16S rRNA and ITS sequences of microorganisms in the rhizosphere soil were sequenced using the Illumina-MiSeq highthroughput sequencing platform. The population structures and community compositions of the bacteria and fungi in the rhizosphere soil were then determined and analyzed. The purpose of this study was to understand how transgenic poplar influences the composition of soil microbial communities before the subsequent environmental release. 【Result】For the composition of bacterial communities, Alpha diversity showed that the Simpson index of betA transgenic poplar was significantly lower than that of the WT, the Shannon and Simpson indexes of WRKY70 transgenic poplar were also significantly lower than that of WT. The fungal indices of the transgenic poplars were significantly lower than those of the WT. The Venn diagram, principal component analysis, and cluster heat map showed that there was little difference in the microbial community structure between TaLEA and WT plants. The microbial communities of transgenic betA and WRKY70 poplars were similar. Based on the composition and abundance analysis at the genus level in the rhizosphere soil collected from transgenic poplars, the abundance of beneficial bacteria, such as Rhodanobacter and Gemmatimonas, increased to varying degrees. The abundance of the beneficial mycorrhizal fungi Inocybe in TaLEA and betA plants was significantly higher than that in the other two samples. The abundance of Sphaerosporella, Hebeloma and Laccaria significantly increased only in TaLEA plants. Conversely, the abundance of pathogenic fungi, such as Didymella and Cadophora, decreased by more than 85% compared with the WT. 【Conclusion】The diversity of rhizosphere microorganisms was influenced by transgenic poplars, which may be beneficial to plant growth and enhance stress resistance. However, more research is needed to prove whether these microorganisms play a vital role.
作者
王阳
王伟
姜静
顾宸瑞
杨蕴力
WANG Yang;WANG Wei;JIANG Jing;GU Chenrui;YANG Yunli(State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University),Harbin 150040,China)
出处
《南京林业大学学报（自然科学版）》
CAS
CSCD
北大核心
2023年第1期199-208,共10页
Journal of Nanjing Forestry University：Natural Sciences Edition
基金
国家林业和草原局生物安全与遗传资源管理项目(KJZXSA202002)。
关键词
转基因小黑杨
根际
细菌
真菌
群落变异
transgenic Populus simonii×P.nigra
rhizosphere
bacteria
fungi
community diversity
