Engineering photoassimilate partitioning in tobacco plants improves growth and productivity and provides pathogen resistance.
Expression of pathogenesis-related (PR) genes is part of the plant's natural defense response against pathogen attack. To study the in vivo role and function of the maize PRms protein, tobacco plants were transformed with the PRms cDNA under the control of the CaMV35S promoter. Transgenic tobacco plants grow faster and yield more leaf and seed biomass. By using immunoelectron microscopy, we found that PRms is associated with plasmodesmata in leaves of transgenic tobacco plants. Furthermore, we found that activation of sucrose efflux from photosynthetically active leaves and accumulation of higher levels of sucrose in leaf tissues are characteristic features of PRms tobacco plants. This, in turn, results in the constitutive expression of endogenous tobacco PR genes and resistance to phytopathogens. The expression of multiple plant defense genes can then be achieved by using a single transgene. These data provide a new approach for engineering disease-resistant plants while simultaneously improving plant yield and productivity through the modification of photoassimilate partitioning.
Murillo
Isabel
I
Departamento de Genética Molecular, Instituto de Biología Molecular de Barcelona, Centro de Investigación y Desarrollo (CID), CSIC. Jordi Girona 18, 08034 Barcelona, Spain.
Roca
Ramón
R
Bortolotti
Cristina
C
Segundo
Blanca San
BS
D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000032:analysis; D017796:Caulimovirus / Q000235:genetics* / Q000472:pathogenicity; D018506:Gene Expression Regulation, Plant; D005818:Genetic Engineering / Q000379:methods; D007113:Immunity, Innate / Q000235:genetics*; D010935:Plant Diseases / Q000821:virology; D018515:Plant Leaves / Q000235:genetics / Q000821:virology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D014026:Nicotiana / Q000235:genetics* / Q000254:growth & development* / Q000821:virology; D014170:Transformation, Genetic
D002241:Carbohydrates