title: Expression of the Nicotiana protein kinase (NPK1) enhanced drought tolerance in transgenic maize.
abstract: 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.
authors.affiliation: Plant Transformation Facility, Department of Agronomy, Iowa State University, Ames, IA 50011-1010, USA.
authors.forename: Huixia
authors.initials: H
authors.lastname: Shou
authors.forename: Patricia
authors.initials: P
authors.lastname: Bordallo
authors.forename: Kan
authors.initials: K
authors.lastname: Wang
mesh_terms: D004190:Disasters; D020930:MAP Kinase Kinase Kinases / Q000235:genetics* / Q000378:metabolism*; D010788:Photosynthesis / Q000502:physiology; D018515:Plant Leaves / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D012639:Seeds; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D014867:Water; D003313:Zea mays / Q000201:enzymology* / Q000235:genetics
chemical_list: D010940:Plant Proteins; D014867:Water; D020930:MAP Kinase Kinase Kinases; C082276:NPK1 protein, Nicotiana tabacum