Direct gene transfer into mature plant seeds using electrical pulses and supersonic treatment
Direct gene transfer into mature plant seeds using electrical pulses and supersonic treatment
Takashi Hagio1, Yoshihiro Ido2, Sakihei Fujiwara2, Koushou Suzuki2, Shinichirou Kamachi1,
Kenichi Konagaya1, Mai Tsuda1, Yutaka Tabei1
1:National Institute of Agrobiological Sciences(2-1-2 Kannondai Tsukuba Ibaraki 305-8602 Japan),
2:Nepa Gene Co., Ltd. (3-1-6 Shioyaki Ichikawa Chiba 272-0114 Japan)
In our previous work, we described the new system that can directly deliver foreign genes into mature seeds of wheat using electroporation (rectangular wave) after vacuum treatment. To further characterize and improve the system, we investigated the GUS(β-glucuronidase) gene expression profiles of mature seeds of some gramineous species changing the parameters of gene transfer conditions adding supersonic treatment. Mature seeds of wheat, barley, maize, rice and sorghum were tested. Supersonic treatment significantly increased the level of GUS gene expression in rice and barley. The optimal electrical conditions for DNA delivery into barley and rice was estimated to be around 50 V/cm, 50ms pulse duration and 50 times of pulses. After the gene transfer treatment the seeds were incubated in water supplemented with 0.5% PVP for two days, and they were transferred to GUS assay buffer. Addition of cellulase into the electroporation buffer also increased the GUS gene expression. Using the knowledge of transient analysis of GUS gene expression, we embarked on the experiment of obtaining stably transformed plats. In rice, presence of nptⅡ gene was confirmed by Southern analysis in T0 and T1 generations.