大豆根系特异表达基因全基因组水平挖掘及其启动子活性鉴定

Genome-scale mining of root-preferential genes from soybean and characterization of their promoter activity

通过改变根系形态建成和提高根系对逆境的抗性可以有效提高作物产量。鉴定根特异性启动子是研究根系发育和对根部性状进行遗传操作的前提。大豆作为一种重要的作物,目前对其根部特异表达基因及启动子尚缺乏系统性的研究。基于大豆幼苗期根、茎、叶片组织的基因转录组数据,本文对大豆根特异或偏好表达的基因启动子进行了挖掘,并通过RT-PCR方法对其中105个候选基因进行了验证,获得33个根特异表达基因,并克隆了其中11个基因启动子(pro1~pro11)。对转基因大豆发状根组织和稳定转化本氏烟草幼苗植株进行GUS染色,结果表明11个启动子均具有显著的根部特异或偏好表达活性。在大豆发状根中,由pro1、pro2、pro8和pro9启动的GUS基因表达活性达到35S的2倍以上。本研究为大豆及其他作物中组织特异性基因及启动子的研究提供了参考。此外,本研究提供的启动子可用于驱动抗性基因在大豆根系组织中特异表达,从而提高大豆对根部病害的抵抗能力,实现品种改良的目的。

Crop yield can be effectively improved by changing root architecture and improving root resistance to stress. Identification of root-specific promoters is prerequisite for research into the regulation of root development and genetic manipulation of root traits. As an important crop species, researches on the genes and promoters specifically expressed in soybean roots is still devoid. In our study, genomic-scale mining of root-specific genes were performed based on the transcriptome date of soybean root, stem and leaf tissues in the seedling stage, among which 105 putative genes were further verified by RT-PCR and 33root-specific genes were identified. Then, 11 promoters(pro1 to pro 11) were cloned from soybean. GUS staining of transgenic soybean hairy roots and Nicotiana benthamiana seedlings showed that the 11 promoters had high root-specific or preferential expression activities. Besides, the GUS enzyme activities driven by pro 1, pro 2, pro 8 and pro 9 were all two folds higher than that of 35S. Our research provided a reference for the identification of tissue specific promoters in soybean and other species. In addition, the promoters identified in this study can be used to drive the specific expression of resistance genes in soybean root tissues, so as to improve the resistance of soybean to root diseases and achieve the purpose of variety improvement.