大豆成熟种子萌发叶片体细胞胚的高频诱导和遗传转化

目的虽然大豆遗传转化取得了较大进展,但其转化效率仍然偏低。因此,有必要建立一个更加简单和高效的大豆转化系统。本研究的目的是以大豆成熟种子萌发产生的叶片(MSDL)为靶外植体,高频诱导和转化大豆体细胞胚(somatic embryos,SEs)。方法萌发7 d的大豆幼苗上摘取叶片,并将其切成1.2 cm×1.2 cm的外植体。将叶片外植体置于胚胎诱导培养基(EIM)上诱导体细胞胚发生。将叶片外植体浸入携带p CAMBIA1301植物表达载体的农杆菌EHA105菌液进行遗传转化。结果MSDL(包括初生叶和次生叶)均能被诱导产生SEs。大多数SE发生在叶片切口处。所试的不同基因型均能诱导SEs。SEs的最高诱导率为95.0%。β葡糖醛酸糖苷酶(GUS)染色结果表明,平均转化效率达到75.4%。DNA印迹(Southern blot)结果表明,目的基因稳定整合在大豆基因组中,拷贝数为1~3个。结论本研究建立了以大豆MSDL为靶组织的体细胞胚高频诱导和遗传转化。该系统有望在大豆基因组编辑技术的开发上得到应用。

含ipt融合基因的根癌农杆菌转化大豆萌动种胚的研究─Ⅰ苗期子叶的同工酶分析

本实验以大豆萌动种胚为受体，用含有３５Ｓ启动子—Ｇｕｓ基因—ｉｐｔ基因—Ｎｏｓ基因的融合基因根癌农杆菌ＬＢＡ４４０４进行转化。通过对转化及对照植株苗期子叶的过氧化物酶同工酶及酯酶同工酶分析，结果表明酶谱有明显差异，过氧化物酶同工酶有两条差异带：Ｒｆ０．５０９及Ｒｆ０．７１２；酯酶同工酶有一条差异带：Ｒｆ０．５３１。综合分析，上述三条差异带都显示的转化植株占所分析的转化植株的１４．４％。此法可作为转基因植株早期筛选的方法之一。

含ipt基因根癌农杆菌转化大豆萌动种胚的同工酶分析

本实验以大豆萌动种胚为受体，用含有ＣａＭＶ３５ｓ启动子－Ｇｕｓ基因－ｉｐｔ基因－Ｎｏｓ基因的融合基因根癌农杆菌ＬＢＡ４４０４进行转化，通过对转化及对照植株苗期根的过氧化物酶同工酶及酯酶同工酶分析，结果表明酶谱有明显差异，酯酶同工酶有一条Ｒｆ为０．５４０的差异带，过氧化物酶同工酶有二条Ｒｆ０．５１４，Ｒｆ０．５３２的差异带；综合分析，上述三条差异带都显示的转化植株占所分析转化植株的１４．４％。用此法可作为转基因植株早期筛选方法之一。

含ipt基因的根癌农杆菌转化大豆萌动种胚的研究──Ⅲ苗期形态特征分析

将含有３５ｓ启动子－Ｇｕｓ基因－ｉｐｔ基因－Ｎｏｓ基因的根癌农杆菌ＬＢＡ４４０４，做为供体．以大豆萌动种胚为受体，用菌液浸染法转化大豆品种黑农３６．对转化植株及对照植株苗期在发芽率、株高、叶子、致瘤等形态特征进行观察．发现转基因植株与对照植株有明显差异．转化植株生长状况明显弱于对照植株．植株矮小、叶子畸形生长，根致瘤率低．间接验证了外源ＤＮＡ的导入．说明苗期形态学分析可做为转基因植株早期筛选的方法之一．

Simultaneous genetic transformation and genome editing of mixed lines in soybean(Glycine max)and maize(Zea mays)

Robust genome editing technologies are becoming part of the crop breeding toolbox.Currently,genome editing is usually conducted either at a single locus,or multiple loci,in a variety at one time.Massively parallel genomics platforms,multifaceted genome editing capabilities,and flexible transformation systems enable targeted variation at nearly any locus,across the spectrum of genotypes within a species.We demonstrate here the simultaneous transformation and editing of many genotypes,by targeting mixed seed embryo explants with genome editing machinery,followed by re-identification through genotyping after plant regeneration.Transformation and Editing of Mixed Lines(TREDMIL)produced transformed individuals representing 101 of 104(97%)mixed elite genotypes in soybean;and 22 of 40(55%)and 9 of 36(25%)mixed maize female and male elite inbred genotypes,respectively.Characterization of edited genotypes for the regenerated individuals identified over 800 distinct edits at the Determinate1(Dt1)locus in samples from 101 soybean genotypes and 95 distinct Brown midrib3(Bm3)edits in samples from 17 maize genotypes.These results illustrate how TREDMIL can help accelerate the development and deployment of customized crop varieties for future precision breeding.