Effects of Acetylacetone Solution Soaking on Agrobacterium - transformed Maize Seed Buds

[Objectives]The effect of acetosyringone seed soaking on the transformation of maize seed buds was analyzed,so as to improve the genetic transformation efficiency of maize and to provide technical support for transgenic breeding of maize.[Methods]The seeds of the"Zheng 58"maize inbred line were used as experimental materials.When the seeds were germinated,AS was added to the water at concentrations of 70,140,210,and 280μmol/L,respectively,and the seeds germinated without the addition of AS served as the CK.The Agrobacterium-mediated method was used to transform bud growth points of maize seeds,and green fluorescent protein detection was performed on the young shoots transformed with EGFP(enhanced green fluorescent protein)gene.The effect of soaking seeds with acetosyringone solution on the transformation of maize bud growth points by Agrobacterium was studied according to the detection results.[Results]Soaking seeds in acetosyringone solutions for germination had the effect of inhibiting the germination of maize seeds and inhibiting sprout elongation,and the higher the concentration of acetosyringone,the stronger the inhibition.When the concentration of acetosyringone solution was 280μmol/L,the germination rate of seeds was only 36.2%of the CK,while soaking seeds with 70-140μmol/L acetosyringone solution for germination could not only ensure a higher germination rate of maize seeds,but also significantly increased the transformation efficiency of maize bud growth points.When the seeds were soaked with 70μmol/L acetosyringone solution for germination,the positive rate of transformed maize buds was the highest,reaching 32.1%.[Conclusions]When maize bud growth points were used as the receptor of Agrobacterium transformation,soaking seeds with 70-140μmol/L acetosyringone for germination basically did not affect the germination of seeds,and was beneficial to the activation of Agrobacterium,thereby promoting the transformation.

Highly efficient genome editing using oocyte-specific zcas9 transgenic zebrafish

Since its first application to induce mutations in mammalian cells （Cong et al., 2013： Mall et al., 2013）, CRISPR/Cas9 has rapidly become a routine technique to perform genome editing in a variety of biological systems due to its facile, robust, and multiplexable fea- tures （Hwang et al, 2013; Wang et al., 2013; Guo et al., 2014; Liu, 2017）.

Screening Chinese soybean genotypes for Agrobacterium-mediated genetic transformation suitability

The Agrobacterium-mediated transformation system is the most commonly used method in soybean transformation.Screening of soybean genotypes favorable for Agrobacterium-infection and tissue regeneration is the most important step to establish an efficient genetic transformation system.In this study,twenty soybean genotypes that originated from different soybean production regions in China were screened for transient infection,regeneration capacity,and stable transgenic efficiency.Three genotypes,Yuechun 04-5,Yuechun 03-3,and Tianlong 1,showed comparable stable transgenic efficiencies with that of the previously reported American genotypes Williams 82 and Jack in our experimental system.For the Tianlong 1,the average stable transformation efficiency is 4.59%,higher than that of control genotypes(Jack and Williams 82),which is enough for further genomic research and genetic engineering.While polymerase chain reaction(PCR),LibertyLink strips,and β-glucuronidase(GUS) staining assays were used to detect the insertion and expression of the transgene,leaves painted with 135 mg/L Basta could efficiently identify the transformants.