Njuguna Elizabeth, Coussens Griet, Neyt Pia, Aesaert Stijn, Storme Veronique, Demuynck Kirin, Vanhaeren Hannes, Dhondt Stijn, Van Haver Yolaine, Paul Linus, Inzé Dirk, Nelissen Hilde, Van Lijsebettens Mieke
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
Int J Dev Biol. 2019;63(1-2):45-55. doi: 10.1387/ijdb.180360mv.
The conserved poly(ADP-ribosyl)ation (PAR) pathway consists of three genetic components that are potential targets to modulate the plant's energy homeostasis upon stress with the aim to improve yield stability in crops and help secure food supply. We studied the role of the PAR pathway component ADP-ribose/NADH pyrophosphohydrolase (AtNUDX7) in yield and mild drought stress by using a transgenic approach in Arabidopsis thaliana and maize (Zea mays). Arabidopsis AtNUDX7 cDNA was overexpressed in Arabidopsis and maize by means of the constitutive Cauliflower Mosaic Virus 35S promoter and the strong constitutive Brachypodium distachyon pBdEF1α promoter, respectively. Overexpression of AtNUDX7 in Arabidopsis improved seed parameters that were measured by a novel, automated method, accelerated flowering and reduced inflorescence height. This combination of beneficial traits suggested that AtNUDX7 overexpression in Arabidopsis might enhance the ADP-ribose recycling step and maintain energy levels by supplying an ATP source in the poly(ADP-ribosyl)ation energy homeostasis pathway. Arabidopsis and maize lines with high, medium and low overexpression levels of the AtNUDX7 gene were analysed in automated platforms and the inhibition of several growth parameters was determined under mild drought stress conditions. The data showed that the constitutive overexpression of the Arabidopsis AtNUDX7 gene in Arabidopsis and maize at varying levels did not improve tolerance to mild drought stress, but knocking down AtNUDX7 expression did, however at the expense of general growth under normal conditions.
保守的多聚（ADP - 核糖）化（PAR）途径由三个遗传成分组成，这些成分是在胁迫下调节植物能量稳态的潜在靶点，目的是提高作物产量稳定性并保障粮食供应。我们通过在拟南芥和玉米（Zea mays）中采用转基因方法，研究了PAR途径成分ADP - 核糖/ NADH焦磷酸水解酶（AtNUDX7）在产量和轻度干旱胁迫中的作用。拟南芥AtNUDX7 cDNA分别通过组成型花椰菜花叶病毒35S启动子和组成型较强的短柄草属pBdEF1α启动子在拟南芥和玉米中过表达。在拟南芥中过表达AtNUDX7改善了通过一种新型自动化方法测量的种子参数，加速了开花并降低了花序高度。这些有益性状的组合表明，拟南芥中AtNUDX7的过表达可能增强ADP - 核糖循环步骤，并通过在多聚（ADP - 核糖）化能量稳态途径中提供ATP来源来维持能量水平。在自动化平台上分析了AtNUDX7基因高、中、低过表达水平的拟南芥和玉米品系，并在轻度干旱胁迫条件下测定了几个生长参数的抑制情况。数据表明，拟南芥AtNUDX7基因在拟南芥和玉米中不同水平的组成型过表达并未提高对轻度干旱胁迫的耐受性，但敲低AtNUDX7表达却有此效果，不过代价是正常条件下的整体生长受到影响。
