拟南芥XERICO基因诱导表达提高转基因植物的耐旱性

Improved Drought Tolerance of Transgenic Arabidopsis thaliana by Inducible Expression of XERICO Gene

构建了PSARK::XERICO植物表达载体,并将其转化到模式植物拟南芥中进行生理表型分析,以期为植/作物抗旱研究提供参考.利用RT-PCR技术从拟南芥幼苗cDNA中扩增出XERICO基因全长,并从pSARK-IPT质粒中分离出SARK启动子,构建植物表达载体pBI121-pSARK-XERICO,然后将构建的表达载体通过浸花法转入野生型拟南芥中,通过抗性筛选和遗传分离分析后获得纯系,对获得的纯合植株进行PCR鉴定,并对其进行种子萌发期间的ABA敏感性分析,以及对它们早期幼苗生长期间经盐分和甘露醇胁迫处理后的表型观察结果进行分析.此外,还对转PSARK::XERICO和野生型拟南芥进行了耐旱性分析.与野生型和xerico突变体相比,转PSARK::XERICO拟南芥对1.0?mol/L ABA、100 mmol/L NaCl和200 mmol/L甘露醇均较敏感;与野生型相比,水分亏缺诱导的XERICO基因在拟南芥中的表达增强了植物对干旱胁迫的耐受性.因此,本研究表明PSARK::XERICO可用于培育耐旱的植物或作物.

To develop drought-resistant plants or crops, we constructed the PSARK：：XERICO plant expression vector and transformed it into the model plant Arabidopsis thaliana （Col-0 ecotype） to analyze the physiological phenotypes. In this study, SARK promoter was isolated from recombinant plasmid of pSARK-IPT; full length of XERICO gene was amplified from the cDNA of Arabidopsis seedlings by the RT-PCR technique; the SARK promoter and the XERICO gene replaced CaMV 35S promoter and GUS gene respectively to obtain the recombinant plasmid, designated as pBI121-pSARK-XERICO. The constructed expression vector was transformed into the wild-type Arabidopsis through the floral dip method. The homozygous lines were obtained through selection of antibiotic resistance and analysis of genetic segregation. The obtained homozygous seedlings were assayed by PCR and evaluated through abscisic acid （ABA） sensitivity analysis during seed germination, and analyzed through the results of phenotypic observation after salinity and mannitol stress treatment during early seedling growth. In addition, the analysis of drought tolerance was conducted between the transgenic PSARK：：XERICO and wild-type Arabidopsis. Compared with the wild-type and xerico mutant plants, the transgenic PSARK：：XERICO plants were more sensitive to 1.0 μmol/L ABA, 100 mmol/L NaCl and 200 mmol/L mannitol. The expression of water deficit-inducible XERICO gene in Arabidopsis enhanced the tolerance to drought stress. Therefore, this study indicated that PSARK：：XERICO has the potential for breeding drought-tolerant plants or crops.