Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.
Plant Biotechnol J. 2011 Apr;9(3):334-47. doi: 10.1111/j.1467-7652.2010.00551.x.
Nucleoside diphosphate kinase 2 (NDPK2) is known to regulate the expression of antioxidant genes in plants. Previously, we reported that overexpression of Arabidopsis NDPK2 (AtNDPK2) under the control of an oxidative stress-inducible SWPA2 promoter in transgenic potato and sweetpotato plants enhanced tolerance to various abiotic stresses. In this study, transgenic poplar (Populus alba × Poplus glandulosa) expressing the AtNDPK2 gene under the control of a SWPA2 promoter (referred to as SN) was generated to develop plants with enhanced tolerance to oxidative stress. The level of AtNDPK2 expression and NDPK activity in SN plants following methyl viologen (MV) treatment was positively correlated with the plant's tolerance to MV-mediated oxidative stress. We also observed that antioxidant enzyme activities such as ascorbate peroxidase, catalase and peroxidase were increased in MV-treated leaf discs of SN plants. The growth of SN plants was substantially increased under field conditions including increased branch number and stem diameter. SN plants exhibited higher transcript levels of the auxin-response genes IAA2 and IAA5. These results suggest that enhanced AtNDPK2 expression affects oxidative stress tolerance leading to improved plant growth in transgenic poplar.
核苷二磷酸激酶 2（NDPK2）已知可调节植物中抗氧化基因的表达。先前，我们报道过在转基因马铃薯和甘薯植物中，在氧化应激诱导型 SWPA2 启动子的控制下过表达拟南芥 NDPK2（AtNDPK2）增强了对各种非生物胁迫的耐受性。在这项研究中，生成了表达 AtNDPK2 基因的转基因杨树（Populus alba×Populus glandulosa），该基因受 SWPA2 启动子的控制（称为 SN），以开发对氧化应激具有增强耐受性的植物。SN 植物中 AtNDPK2 的表达水平和 NDPK 活性在甲基紫精（MV）处理后与植物对 MV 介导的氧化应激的耐受性呈正相关。我们还观察到，在 MV 处理的 SN 植物叶片中，抗氧化酶如抗坏血酸过氧化物酶、过氧化氢酶和过氧化物酶的活性增加。在包括增加分枝数和茎直径的田间条件下，SN 植物的生长显著增加。SN 植物表现出更高的生长素反应基因 IAA2 和 IAA5 的转录水平。这些结果表明，增强的 AtNDPK2 表达影响氧化应激耐受性，从而导致转基因杨树的生长改善。
