Wang Yang, Ying Jifeng, Kuzma Monika, Chalifoux Maryse, Sample Angela, McArthur Charlene, Uchacz Tina, Sarvas Carlene, Wan Jiangxin, Dennis David T, McCourt Peter, Huang Yafan
Performance Plants, Inc., Bioscience Complex, Queen's University, Kingston, ON, Canada K7L 3N6.
Plant J. 2005 Aug;43(3):413-24. doi: 10.1111/j.1365-313X.2005.02463.x.
Protecting crop yield under drought stress is a major challenge for modern agriculture. One biotechnological target for improving plant drought tolerance is the genetic manipulation of the stress response to the hormone abscisic acid (ABA). Previous genetic studies have implicated the involvement of the beta-subunit of Arabidopsis farnesyltransferase (ERA1) in the regulation of ABA sensing and drought tolerance. Here we show that molecular manipulation of protein farnesylation in Arabidopsis, through downregulation of either the alpha- or beta-subunit of farnesyltransferase enhances the plant's response to ABA and drought tolerance. To test the effectiveness of tailoring farnesylation in a crop plant, transgenic Brassica napus carrying an ERA1 antisense construct driven by a drought-inducible rd29A promoter was examined. In comparison with the non-transgenic control, transgenic canola showed enhanced ABA sensitivity, as well as significant reduction in stomatal conductance and water transpiration under drought stress conditions. The antisense downregulation of canola farnesyltransferase for drought tolerance is a conditional and reversible process, which depends on the amount of available water in the soil. Furthermore, transgenic plants were more resistant to water deficit-induced seed abortion during flowering. Results from three consecutive years of field trial studies suggest that with adequate water, transgenic canola plants produced the same amount of seed as the parental control. However, under moderate drought stress conditions at flowering, the seed yields of transgenic canola were significantly higher than the control. Using protein farnesyltransferase as an effective target, these results represent a successful demonstration of engineered drought tolerance and yield protection in a crop plant under laboratory and field conditions.
在干旱胁迫下保护作物产量是现代农业面临的一项重大挑战。提高植物耐旱性的一个生物技术目标是对激素脱落酸（ABA）应激反应进行基因操纵。先前的遗传学研究表明，拟南芥法尼基转移酶（ERA1）的β亚基参与ABA感知和耐旱性的调控。在此我们表明，通过下调法尼基转移酶的α亚基或β亚基对拟南芥中的蛋白质法尼基化进行分子操纵，可增强植物对ABA的反应和耐旱性。为了测试在作物中定制法尼基化的有效性，研究了携带由干旱诱导型rd29A启动子驱动的ERA1反义构建体的转基因甘蓝型油菜。与非转基因对照相比，转基因油菜在干旱胁迫条件下表现出增强的ABA敏感性，气孔导度和水分蒸腾显著降低。油菜法尼基转移酶的反义下调以实现耐旱性是一个有条件且可逆的过程，这取决于土壤中的可用水量。此外，转基因植物在开花期间对水分亏缺诱导的种子败育更具抗性。连续三年的田间试验研究结果表明，在水分充足的情况下，转基因油菜植株产生的种子量与亲本对照相同。然而，在开花期的中度干旱胁迫条件下，转基因油菜的种子产量显著高于对照。以蛋白质法尼基转移酶作为有效靶点，这些结果成功证明了在实验室和田间条件下对作物进行耐旱性工程改造和产量保护。
