Conforte Alessandra Jordano, Guimarães-Dias Fábia, Neves-Borges Anna Cristina, Bencke-Malato Marta, Felix-Whipps Durvalina, Alves-Ferreira Márcio
Department of Genetics. Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
Department of Botany. Universidade Federal do Estado do Rio de Janeiro (UNIRIO), Rio de Janeiro, RJ, Brazil.
Genet Mol Biol. 2017;40(1 suppl 1):226-237. doi: 10.1590/1678-4685-GMB-2016-0052. Epub 2017 Mar 27.
Drought stress is the main limiting factor of soybean yield. Currently, genetic engineering has been one important tool in the development of drought-tolerant cultivars. A widely used strategy is the fusion of genes that confer tolerance under the control of the CaMV35S constitutive promoter; however, stress-responsive promoters would constitute the best alternative to the generation of drought-tolerant crops. We characterized the promoter of α-galactosidase soybean (GlymaGAL) gene that was previously identified as highly up-regulated by drought stress. The β-glucuronidase (GUS) activity of Arabidopsis transgenic plants bearing 1000- and 2000-bp fragments of the GlymaGAL promoter fused to the uidA gene was evaluated under air-dried, polyethylene glycol (PEG) and salt stress treatments. After 24 h of air-dried and PEG treatments, the pGAL-2kb led to an increase in GUS expression in leaf and root samples when compared to the control samples. These results were corroborated by qPCR expression analysis of the uidA gene. The pGAL-1kb showed no difference in GUS activity between control and treated samples. The pGAL-2kb promoter was evaluated in transgenic soybean roots, leading to an increase in EGFP expression under air-dried treatment. Our data indicates that pGAL-2kb could be a useful tool in developing drought-tolerant cultivars by driving gene expression.
干旱胁迫是大豆产量的主要限制因素。目前，基因工程已成为培育耐旱品种的一项重要工具。一种广泛使用的策略是在组成型CaMV35S启动子的控制下融合赋予耐受性的基因；然而，胁迫响应启动子将是培育耐旱作物的最佳选择。我们对先前被鉴定为受干旱胁迫高度上调的大豆α-半乳糖苷酶（GlymaGAL）基因的启动子进行了表征。在风干、聚乙二醇（PEG）和盐胁迫处理下，对携带与uidA基因融合的GlymaGAL启动子1000bp和2000bp片段的拟南芥转基因植物的β-葡萄糖醛酸酶（GUS）活性进行了评估。在风干和PEG处理24小时后，与对照样品相比，pGAL-2kb导致叶片和根样品中GUS表达增加。uidA基因的qPCR表达分析证实了这些结果。pGAL-1kb在对照和处理样品之间的GUS活性没有差异。在转基因大豆根中评估了pGAL-2kb启动子，在风干处理下导致EGFP表达增加。我们的数据表明，pGAL-2kb通过驱动基因表达可能成为培育耐旱品种的有用工具。
