转Bt基因水稻根际土壤微生物多样性的磷脂脂肪酸(PLFAs)表征

Microbial diversity in rhizosphere soil of transgenic Bt rice based on the characterization of phospholipids fatty acids.

以亲本水稻为对照,应用13C脉冲标记和磷脂脂肪酸技术,分析转Bt基因对水稻根际微生物多样性的影响.结果表明:转Bt基因水稻与亲本水稻根际均以饱和脂肪酸和支链脂肪酸为主,单不饱和脂肪酸次之,多不饱和脂肪酸最少.苗期、拔节期和抽穗期,转Bt基因水稻根际革兰氏阳性菌(G+)代表性磷脂脂肪酸含量显著低于亲本水稻;革兰氏阴性菌(G-)代表性磷脂脂肪酸含量显著高于亲本水稻.水稻各生育期,转Bt基因未对水稻根际土壤真菌、放线菌磷脂脂肪酸含量造成显著影响,且转Bt基因水稻与亲本水稻根际微生物磷脂脂肪酸13 C含量无显著性差异.表明外源Bt基因插入仅对水稻根际微生物多样性造成短暂影响,不具有持续性.

Taking non-transgenic parental rice as the control,and by using 13C pulse-chase labeling method coupled with phospholipid fatty acid（PLFA） analysis,this paper studied the effects of transgenic Bt rice on the microbial diversity in rhizosphere soil.The results showed that in the rhizosphere soils of transgenic Bt rice and its non-transgenic parent,saturated PLFAs and branched PLFAs were the main,followed by monounsaturated PLFAs,and polyunsaturated PLFAs.A significantly lower amount of Gram-positive bacterial PLFAs and a higher amount of Gram-negative bacterial PLFAs were observed in the rhizosphere soil of transgenic Bt rice at its seedling,booting,and heading stages,as compared with the control.In the whole growth period of rice,transgenic Bt gene had no significant effects on the fungal and actinomycete PLFAs in rhizosphere soil,and no significant difference was observed in the rhizosphere soil 13C-PLFA content between transgenic Bt rice and its non-transgenic parent.These findings indicated that the insertion of exogenous cry1Ab gene into rice only had temporary effects on the microbial community composition in the rhizosphere soil of rice.