Expression of the Nicotiana protein kinase (NPK1) enhanced drought tolerance in transgenic maize

• Published in: Journal of experimental botany 2004-05, Vol.55 (399), p.1013-1019
• Main Authors: Shou, H, Bordallo, P, Wang, K
• Format: Article
• Language: English
• Subjects: Corn; Disasters; DNA; Drought; Drought tolerance; MAP Kinase Kinase Kinases - genetics; MAP Kinase Kinase Kinases - metabolism; Nicotiana - enzymology; Nicotiana - genetics; Nicotiana - physiology; Nicotiana protein kinase; Oxidative stress; Photosynthesis; Photosynthesis - physiology; photosynthesis rate; Plant Leaves - physiology; Plant physiology; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; Plants, Genetically Modified - enzymology; Polymerase Chain Reaction; Research Papers: Cell and Molecular Biology, Biochemistry and Molecular Physiology; Restriction Mapping; Seeds; Signal Transduction - genetics; Signal Transduction - physiology; Transgenes; transgenic maize; Transgenic plants; Water; Zea mays; Zea mays - enzymology; Zea mays - genetics
• ISSN: 0022-0957; 1460-2431; 1460-2431
• DOI: 10.1093/jxb/erh129

Drought is one of the most important abiotic stresses affecting the productivity of maize. Previous studies have shown that expression of a mitogen-activated protein kinase kinase kinase (MAPKKK) gene activated an oxidative signal cascade and led to the tolerance of freezing, heat, and salinity stress in transgenic tobacco. To analyse the role of activation of oxidative stress signalling in improving drought tolerance in major crops, a tobacco MAPKKK (NPK1) was expressed constitutively in maize. Results show that NPK1 expression enhanced drought tolerance in transgenic maize. Under drought conditions, transgenic maize plants maintained significantly higher photosynthesis rates than did the non-transgenic control, suggesting that NPK1 induced a mechanism that protected photosynthesis machinery from dehydration damage. In addition, drought-stressed transgenic plants produced kernels with weights similar to those under well-watered conditions, while kernel weights of drought-stressed non-transgenic control plants were significantly reduced when compared with their non-stressed counterparts.