Instituto Federal Goiano, Departamento de Ciências Biológicas, Laboratório de Biotecnologia, 75790-000, Urutaí, GO, Brazil.
Universidade Federal do Rio de Janeiro, Nupem, Laboratório de Biotecnologia Vegetal, 27910-970, Macaé, RJ, Brazil.
Plant Physiol Biochem. 2017 Dec;121:38-47. doi: 10.1016/j.plaphy.2017.10.012. Epub 2017 Oct 20.
Aquaporins (AQPs) and aquaglyceroporins (AQGPs) are integral membrane proteins that mediate the transport of water and solutes, such as glycerol and urea, across membranes. AQP and AQGP genes represent a valuable tool for biotechnological improvement of plant tolerance to environmental stresses. We previously isolated a gene encoding for an aquaglyceroporin (ThAQGP), which was up-regulated in Trichoderma harzianum during interaction with the plant pathogen Fusarium solani. This gene was introduced into Nicotiana tabacum and plants were physiologically characterized. Under favorable growth conditions, transgenic progenies did not had differences in both germination and growth rates when compared to wild type. However, physiological responses under drought stress revealed that transgenic plants presented significantly higher transpiration rate, stomatal conductance, photosynthetic efficiency and faster turgor recovery than wild type. Quantitative RT-PCR analysis demonstrated the presence of ThAQGP transcripts in transgenic lines, showing the cause-effect relationship between the observed phenotype and the expression of the transgene. Our results underscore the high potential of T. harzianum as a source of genes with promising applications in transgenic plants tolerant to drought stress.
水通道蛋白（AQPs）和甘油通道蛋白（AQGPs）是介导水和溶质（如甘油和尿素）跨膜运输的完整膜蛋白。AQP 和 AQGP 基因代表了生物技术提高植物对环境胁迫耐受性的有价值工具。我们之前分离出一个编码甘油通道蛋白（ThAQGP）的基因，该基因在木霉与植物病原菌镰刀菌互作过程中上调表达。该基因被导入烟草，对植物进行了生理学特性分析。在有利的生长条件下，与野生型相比，转基因后代在发芽率和生长速率方面没有差异。然而，干旱胁迫下的生理响应表明，与野生型相比，转基因植物具有更高的蒸腾速率、气孔导度、光合效率和更快的膨压恢复。定量 RT-PCR 分析表明，转基因系中存在 ThAQGP 转录本，表明观察到的表型与转基因表达之间存在因果关系。我们的结果强调了木霉作为具有应用前景的耐旱转基因植物基因源的巨大潜力。
