Matsui Takeshi, Takita Eiji, Oiwa Seika, Yokoyama Asuka, Kato Ko, Sawada Kazutoshi
Advanced Technology Research Laboratories, Idemitsu Kosan Co., Ltd., 1280 Kamiizumi, Sodegaura, Chiba 299-0293, Japan.
Graduate School of Science and Technology, Nara Institute of Science and Technology (NAIST), 8916-5 Takayamacho, Ikoma, Nara 630-0192, Japan.
Plant Biotechnol (Tokyo). 2021 Jun 25;38(2):239-246. doi: 10.5511/plantbiotechnology.21.0414a.
Plant-made oral vaccines can be a cost-effective method to control infectious diseases of humans and farm animals. Pig edema is a bacterial disease caused by enterohemorrhagic producing the toxin Shiga toxin 2e (Stx2e). In our previous report, we chose the non-toxic B subunit of Stx2e (Stx2eB) as a vaccine antigen, and Stx2eB was expressed in lettuce ( L., cv. Green wave). We found that a double repeated Stx2eB (2×Stx2eB) accumulates to higher levels than a single Stx2eB. In this study, we analyzed progeny plants introduced with 2×Stx2eB in which the gene was expressed under the control of conventional cauliflower mosaic virus 35S RNA (CaMV 35S) promoter, and found that the lettuce underwent transgene silencing and bore few seeds. We resolved these problems by using a transgene cassette which harbored a transcriptional promoter derived from the lettuce gene and a longer version of HSPT. The lettuce harboring this expression construct will be valuable in establishing the seed lot system on the basis that thousands of seeds can be obtained from one plant body and the resulting progeny plants accumulate 2×Stx2eB at high levels without the transgene silencing.
植物源口服疫苗可能是一种控制人类和家畜传染病的经济有效方法。猪水肿病是一种由产志贺毒素2e（Stx2e）的肠出血性细菌引起的疾病。在我们之前的报告中，我们选择了无毒的Stx2e B亚基（Stx2eB）作为疫苗抗原，并在生菜（L.，品种绿波）中表达了Stx2eB。我们发现，双重复的Stx2eB（2×Stx2eB）比单拷贝的Stx2eB积累水平更高。在本研究中，我们分析了导入2×Stx2eB的子代植株，该基因在传统花椰菜花叶病毒35S RNA（CaMV 35S）启动子控制下表达，发现生菜发生了转基因沉默且结籽很少。我们通过使用一个转基因盒解决了这些问题，该转基因盒含有一个源自生菜基因的转录启动子和一个更长版本的HSPT。携带这种表达构建体的生菜对于建立种子批系统将具有重要价值，因为从一个植株体可以获得数千粒种子，并且产生的子代植株能够高水平积累2×Stx2eB而不会发生转基因沉默。
