Bt基因导入对侵染丛枝菌根真菌的玉米生长生理及磷转运基因表达的影响

Effect of Bt gene insertion on growth,physiology and gene expression of phosphorus transporter gene of corn after arbuscular mycorrhizal fungi colonization

为了分析Bt玉米与常规玉米对接种丛枝菌根真菌响应的异同,本文在接种摩西球囊霉(Funneliformis mosseae)和不接种的条件下,对比分析了两个Bt玉米品种‘5422Bt1’(Bt11)和‘5422CBCL’(Mon810)以及同源常规玉米品种‘5422’根系中丛枝菌根真菌侵染率、磷转运基因的表达量、生长和养分利用状况。结果表明:生长50 d和80 d时,Bt玉米‘5422Bt1’和‘5422CBCL’根系丛枝菌根真菌侵染率显著高于常规玉米‘5422’,分别比‘5422’高13.54%、11.24%和9.83%、6.70%;50 d取样时,接菌和不接菌处理玉米‘5422Bt1’、‘5422CBCL’和‘5422’根系内的磷转运基因表达量均没有显著差异;接菌和不接菌处理下玉米‘5422Bt1’的干重显著高于‘5422CBCL’相应的处理,而与‘5422’没有显著差异;80 d取样时,不接菌处理玉米‘5422Bt1’的根长、根表面积和根体积显著高于‘5422’和‘5422CBCL’不接菌处理。Bt基因的导入主要影响了两个Bt玉米品种(‘5422Bt1’和‘5422CBCL’)苗期(50 d)和成熟期(80 d)的氮素吸收利用,与常规玉米品种‘5422’相比,合成Bt蛋白消耗了部分氮素和磷;3个玉米品种对接种AMF的响应不同,接菌处理提高了‘5422Bt1’和‘5422CBCL’苗期(50 d)和成熟期(80 d)的氮素吸收利用。在磷养分条件满足玉米生长需要的条件下,接种丛枝菌根真菌对Bt玉米磷转运基因表达量和磷的吸收利用没有显著影响。Bt基因的导入以及接种F.mosseae对Bt玉米生长和养分利用的影响与不同转化事件形成的品种特性相关。

Bt(Bacillus thuringiensis)-corn root can exudate insecticide active Bt protein and persistent toxin in soils which can affect symbiotic relationship between corn and arbuscular mycorrhizal fungi(AMF).In this paper,two Bt-corn varieties‘5422Bt1’(Bt11)and‘5422CBCL’(Mon810),and one conventional corn variety‘5422’were used to explore the difference between Bt and non-Bt varieties with Funneliformis mosseae inoculation and non-inoculation treatments.The colonization of AMF,phosphorus transporter gene expression,growth and nutrients contents were measured after50d and80d of inoculation.The results showed that AMF colonization of Bt-corn varieties‘5422Bt1’and‘5422CBCL’were significantly higher than that of the conventional variety‘5422’at50d and80d after treatment,which increased by13.54%and11.24%at50d and then by9.83%and6.70%at80d,respectively.There was no significant difference in phosphorus transporter gene expression between inoculation and non-inoculation for Bt-corn varieties at50d.The height of‘5422’under inoculation treatment was significantly higher than that of‘5422Bt1’and‘5422CBCL’at50d.Dry weight of‘5422Bt1’under inoculation treatment was significantly higher than that of‘5422CBCL’at50d.The root length,root surface and root volume of‘5422Bt1’were significantly higher than those of‘5422’and‘5422CBCL’under non-inoculation treatments at80d.Bt gene insertion affected nitrogen concentration of the two Bt-corn varieties(‘5422Bt1’and‘5422CBCL’)at the two sampling times.As compared with conventional corn variety,the two Bt-corn varieties needed more nitrogen and phosphorus to synthetize Bt protein.There were significant differences among the responses of three corn varieties to AMF inoculation.F.mosseae inoculation significantly increased nitrogen absorption of‘5422Bt1’and‘5422CBCL’at the two sampling times(50d and80d).In conclusion,the effect of Bt-gene insertion and AMF inoculation on growth and nutrient utilization of Bt-corn was mainly dependent on its transformation event.