抗虫转基因水稻及其杂交水稻对土壤微生物群落多样性与组成的影响

Effect of insect-resistant transgenic rice and its hybrid combination rice on diversity and composition of soil microbial community

微生物是土壤物质循环与肥力演变的驱动者,其群落组成关系到土壤微生态系统的稳定与可持续性。对抗虫转基因水稻土壤微生物群落变化的研究是其环境安全性评价的重要内容。本研究基于细菌16S rRNA基因和真菌ITS基因的高通量测序,分析了田间试验中抗虫转基因水稻‘MFB’及其转基因杂交水稻‘闽丰A/MFB’‘天丰A/MFB’和‘谷丰A/MFB’与非转基因常规水稻‘闽恢3301’及杂交水稻‘天优华占’的土壤微生物群落多样性与组成的差异,并得出以下结果。首先,与两个非转基因水稻品种相比,抗虫转基因水稻及转基因杂交水稻均能显著增产(P<0.05)。同时,高通量测序结果表明,除水稻成熟期的土壤真菌群落外,与‘闽恢3301’相比‘MFB’的土壤细菌或真菌群落的α-多样性指数Chao1、Observed_species和Shannon均有所提高,且分别在水稻成熟期或分蘖期达到显著性水平(P<0.05);水稻齐穗期转基因杂交水稻‘闽丰A/MFB’‘天丰A/MFB’和‘谷丰A/MFB’的土壤细菌及真菌群落的多样性指数Shannon均介于‘MFB’与‘天优华占’之间;微生物群落β-多样性分析结果表明,本田间试验中不同品种水稻土壤细菌或真菌的群落组成均没有显著差异。但与‘闽恢3301’相比,稻田土壤细菌中丰度最高的变形菌门的相对丰度在‘MFB’土壤中明显增加,且在水稻分蘖期及成熟期达显著水平(P<0.05),而土壤真菌中丰度最高的子囊菌门的相对丰度在‘MFB’土壤中明显减少,且在水稻分蘖期及齐穗期差异显著(P<0.05);水稻齐穗期‘闽丰A/MFB’‘天丰A/MFB’和‘谷丰A/MFB’的土壤变形菌门或子囊菌门的相对丰度也均介于‘MFB’与‘天优华占’之间。此外,通过对微生物群落的功能组成预测可见,随水稻生长,‘MFB’与‘闽恢3301’的土壤细菌群落功能组成间差异存在增大的趋势。综上所述,本研究田间试验中,抗虫转基因水稻及其转基因杂交水稻在增产的同时提高了稻田土壤细菌或真菌群落的多样性,改变了主要细菌或真菌种类的相对丰度,但对细菌或真菌的群落及功能组成的影响不显著。

Microorganisms drive the soil material cycle and evolution of fertility,and their community composition is related to the stability and sustainability of the soil microecosystem.The study of changes in the soil microbial community in insect-resistant transgenic rice is an important part of environmental safety assessments.Based on high-throughput sequencing of the bacterial 16S rRNA and fungal ITS genes,this study analyzed the differences in diversity and composition of microbial communities in paddy soils with insect-resistant transgenic rice‘MFB’,insect-resistant transgenic hybrid rice‘Minfeng A/MFB’‘Tianfeng A/MFB’or‘Gufeng A/MFB’and non-transgenic conventional rice‘Minhui 3301’or hybrid rice‘Tianyouhuazhan’.The results showed that,compared with non-transgenic conventional rice‘Minhui 3301’or hybrid rice‘Tianyouhuazhan’,both insect-resistant transgenic rice‘MFB’and transgenic hybrid rice‘Minfeng A/MFB’‘Tianfeng A/MFB’or‘Gufeng A/MFB’could significantly increase the yield(P<0.05).At the same time,high-throughput sequencing showed that theα-diversity indexes of Chao1,Observed_species,and Shannon of bacterial or fungal communities in paddy soil with‘MFB’were higher than those in soil with‘Minhui 3301’at all stage except for fungal communities at rice maturation stage,and the differences at rice maturation or tillering stage are significant(P<0.05).At the heading stage of rice,the values ofα-diversity indexes of Shannon of bacterial or fungal communities in paddy soils with the insect-resistant transgenic hybrid rice‘Minfeng A/MFB’‘Tianfeng A/MFB’or‘Gufeng A/MFB’were between those of soils with‘MFB’and‘Tianyouhuazhan’.The results ofβ-diversity analysis of bacterial or fungal communities showed that there were no significant differences in the composition of microbial communities in paddy soils with different varieties of rice in this field experiment.However,the relative abundance of Proteobacteria,which showed the highest abundance of bacteria,in paddy soil with‘MFB’increased compared with that of‘Minhui 3301’,and reached the significance level at the tillering and maturation stage of rice(P<0.05).In contrast,the relative abundance of Ascomycota,which showed the highest abundance of fungi,was reduced in paddy soil with‘MFB’and reached the significance level at the tillering and heading stages of rice(P<0.05).At the heading stage of rice,the relative abundances of Proteobacteria and Ascomycota in paddy soils with‘Minfeng A/MFB’‘Tianfeng A/MFB’or‘Gufeng A/MFB’were between those of soils with‘MFB’and‘Tianyouhuazhan’.According to the functional prediction of microbial communities,the differences in functional composition of bacterial communities in paddy soil between soils with‘MFB’and‘Minhui 3301’gradually increased with rice growth.In summary,insect-resistant transgenic rice and its transgenic hybrid rice increased the diversity of soil bacterial and fungal communities and changed the relative abundance of major bacterial and fungal species with increased yield,but did not have significant effects on the community and functional composition of bacteria or fungi.