Engineering photoassimilate partitioning in tobacco plants improves growth and productivity and provides pathogen resistance

• Published in: The Plant journal : for cell and molecular biology 2003-11, Vol.36 (3), p.330-341
• Main Authors: Murillo, Isabel, Roca, Ramón, Bortolotti, Cristina, Segundo, Blanca San
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Carbohydrate Metabolism; Carbohydrates - analysis; Caulimovirus - genetics; Caulimovirus - pathogenicity; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Genetic Engineering - methods; Genetics and breeding of economic plants; Immunity, Innate - genetics; Nicotiana; Nicotiana - genetics; Nicotiana - growth & development; Nicotiana - virology; Nicotiana tabacum; pathogen; pathogenesis-related gene; pathogenesis‐related; Pest resistance; Plant Diseases - virology; Plant Leaves - genetics; Plant Leaves - virology; Plant pathogens; Plants, Genetically Modified; plasmodesmata; PRms; PRms protein; Promoter Regions, Genetic; sucrose; Transformation, Genetic; Varietal selection. Specialized plant breeding, plant breeding aims; Zea mays
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313X.2003.01880.x

Summary 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.