Vendruscolo Eliane Cristina Gruszka, Schuster Ivan, Pileggi Marcos, Scapim Carlos Alberto, Molinari Hugo Bruno Correa, Marur Celso Jamil, Vieira Luiz Gonzaga Esteves
Universidade Federal do Paraná-Campus Palotina, Rua Pioneiro, 2153, CEP 85950-000 Palotina-Pr, Brazil.
J Plant Physiol. 2007 Oct;164(10):1367-76. doi: 10.1016/j.jplph.2007.05.001. Epub 2007 Jul 2.
Water deficit is one of the main abiotic factors that affect spring wheat planted in subtropical regions. Accumulation of proline appears to be a promising approach to maintain the productivity of plants under stress condition. However, morphological alterations and growth reduction are observed in transgenic plants carrying genes coding for osmoprotectants controlled by constitutive promoters. We report here the effects of water deficit on wheat plants transformed with the Vigna aconitifolia Delta(1)-pyrroline-5-carboxylate synthetase (P5CS) cDNA that encodes the key regulatory enzyme in proline biosynthesis, under the control of a stress-induced promoter complex-AIPC. Transgenic wheat plants submitted to 15 days of water shortage presented a distinct response. We have found that drought resulted in the accumulation of proline. The tolerance to water deficit observed in transgenic plants was mainly due to protection mechanisms against oxidative stress and not caused by osmotic adjustment.
水分亏缺是影响亚热带地区种植的春小麦的主要非生物因素之一。脯氨酸的积累似乎是在胁迫条件下维持植物生产力的一种有前景的方法。然而，在携带由组成型启动子控制的编码渗透保护剂的基因的转基因植物中，观察到形态改变和生长减缓。我们在此报告水分亏缺对用豇豆Δ(1)-吡咯啉-5-羧酸合成酶（P5CS）cDNA转化的小麦植株的影响，该cDNA在胁迫诱导启动子复合物-AIPC的控制下编码脯氨酸生物合成中的关键调节酶。经受15天缺水的转基因小麦植株表现出明显的反应。我们发现干旱导致脯氨酸积累。转基因植物中观察到的对水分亏缺的耐受性主要归因于针对氧化应激的保护机制，而非渗透调节所致。
