De Block Marc, Verduyn Christoph, De Brouwer Dirk, Cornelissen Marc
Bayer BioScience N.V., Technologiepark 38, 9052 Gent, Belgium.
Plant J. 2005 Jan;41(1):95-106. doi: 10.1111/j.1365-313X.2004.02277.x.
Plants contain two genes that code for poly(ADP-ribose) polymerase (PARP): parp1 and parp2. Both PARPs are activated by DNA damage caused by, example reactive oxygen species. Upon activation polymers of ADP-ribose are synthesized on a range of nuclear enzymes using NAD(+) as substrate. Here, we show that in plants stresses such as drought, high light and heat activate PARP causing NAD(+) breakdown and ATP consumption. When the PARP activity is reduced by means of chemical inhibitors or by gene silencing, cell death is inhibited and plants become tolerant to a broad range of abiotic stresses like high light, drought and heat. Plant lines with low poly(ADP-ribosyl)ation activity maintain under stress conditions their energy homeostasis by reducing NAD(+) breakdown and consequently energy consumption. The higher energy-use efficiency avoids the need for a too intense mitochondrial respiration and consequently reduces the formation of reactive oxygen species. From these results it can be concluded that breeding or engineering for a high energy-use efficiency under stress conditions is a valuable, but until today nearly unexploited, approach to enhance overall stress tolerance of crops.
植物含有两个编码聚（ADP - 核糖）聚合酶（PARP）的基因：parp1和parp2。这两种PARP都可被例如活性氧等引起的DNA损伤激活。激活后，以NAD(+)为底物，在一系列核酶上合成ADP - 核糖聚合物。在此，我们表明在植物中，诸如干旱、高光和高温等胁迫会激活PARP，导致NAD(+)分解和ATP消耗。当通过化学抑制剂或基因沉默降低PARP活性时，细胞死亡受到抑制，植物对高光、干旱和高温等多种非生物胁迫产生耐受性。聚（ADP - 核糖基）化活性低的植物品系在胁迫条件下通过减少NAD(+)分解进而减少能量消耗来维持其能量稳态。更高的能量利用效率避免了过度强烈的线粒体呼吸的需要，从而减少了活性氧的形成。从这些结果可以得出结论，培育或改造在胁迫条件下具有高能量利用效率的作物是提高作物整体胁迫耐受性的一种有价值但至今几乎未被开发的方法。
