Abstract Water deficit is an important climatic problem that can impair agriculture yield and economy. Genetically modified soybean plants containing the AtNCED3 gene were obtained aiming drought-tolerance improvement. The NCED3 gene encodes a 9-cis-epoxycarotenoid dioxygenase (NCED, EC 1.13.11.51), an important enzyme in abscisic acid biosynthesis. ABA activates the expression of drought-responsive genes, in water-deficit conditions, targeting defense mechanisms and enabling plants to survive under low water availability. Results from greenhouse experiments showed that the transgene AtNCED3 and the endogenous genes GmAREB1, GmPP2C, GmSnRK2 and GmAAO3 presented higher expression under water deficit (WD) in the event 2Ha11 than in WT-plants. No significant correlation was observed between the plant materials and WD conditions for growth parameters; however, gas exchange measurements decreased in the GM event, which also showed 80% higher intrinsic water use when compared to WT plants. In crop season 2015/16, event 2Ha11 showed higher total number of pods, higher number of pods with seeds and yield than WT plants. ABA concentration was also higher in GM plants under WD. These results obtained in field screenings suggest that AtNCED3 soybean plants might outperform under drought, reducing economic and yield losses, thus being a good candidate line to be incorporated in the soybean-breeding program to develop drought-tolerant cultivars.

中文翻译：

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AtNCED3基因的过表达提高了温室和大田条件下大豆的耐旱性

摘要 缺水是影响农业产量和经济的重要气候问题。获得了含有 AtNCED3 基因的转基因大豆植物，旨在提高耐旱性。NCED3 基因编码 9-顺式-环氧类胡萝卜素双加氧酶 (NCED, EC 1.13.11.51)，这是脱落酸生物合成中的一种重要酶。ABA 激活干旱响应基因的表达，在缺水条件下，靶向防御机制并使植物能够在缺水条件下生存。温室实验结果表明，转基因 AtNCED3 和内源基因 GmAREB1、GmPP2C、GmSnRK2 和 GmAAO3 在缺水 (WD) 事件 2Ha11 中比在 WT 植物中表现出更高的表达。在植物材料和 WD 条件之间没有观察到生长参数的显着相关性；然而，转基因事件中的气体交换测量值下降，与 WT 植物相比，这也显示出 80% 的内在用水量。在 2015/16 作物季节，事件 2Ha11 显示出比 WT 植物更高的豆荚总数、有种子的豆荚数和产量。在 WD 下转基因植物中的 ABA 浓度也较高。在田间筛选中获得的这些结果表明，AtNCED3 大豆植物可能在干旱条件下表现更好，减少经济和产量损失，因此是一个很好的候选品系，可以纳入大豆育种计划以开发耐旱品种。与 WT 植物相比，具有种子和产量的豆荚数量更多。在 WD 下转基因植物中的 ABA 浓度也较高。在田间筛选中获得的这些结果表明，AtNCED3 大豆植物可能在干旱条件下表现更好，减少经济和产量损失，因此是一个很好的候选品系，可以纳入大豆育种计划以开发耐旱品种。与 WT 植物相比，具有种子和产量的豆荚数量更多。在 WD 下转基因植物中的 ABA 浓度也较高。在田间筛选中获得的这些结果表明，AtNCED3 大豆植物可能在干旱条件下表现更好，减少经济和产量损失，因此是一个很好的候选品系，可以纳入大豆育种计划以开发耐旱品种。