Overexpression of the brassinosteroid biosynthetic gene DWF4 in Brassica napus simultaneously increases seed yield and stress tolerance.
As a resource allocation strategy, plant growth and defense responses are generally mutually antagonistic. Brassinosteroid (BR) regulates many aspects of plant development and stress responses, however, genetic evidence of its integrated effects on plant growth and stress tolerance is lacking. We overexpressed the Arabidopsis BR biosynthetic gene AtDWF4 in the oilseed plant Brassica napus and scored growth and stress response phenotypes. The transgenic B. napus plants, in comparison to wild type, displayed increased seed yield leading to increased overall oil content per plant, higher root biomass and root length, significantly better tolerance to dehydration and heat stress, and enhanced resistance to necrotrophic fungal pathogens Leptosphaeria maculans and Sclerotinia sclerotiorum. Transcriptome analysis supported the integrated effects of BR on growth and stress responses; in addition to BR responses associated with growth, a predominant plant defense signature, likely mediated by BES1/BZR1, was evident in the transgenic plants. These results establish that BR can interactively and simultaneously enhance abiotic and biotic stress tolerance and plant productivity. The ability to confer pleiotropic beneficial effects that are associated with different agronomic traits suggests that BR-related genes may be important targets for simultaneously increasing plant productivity and performance under stress conditions.
Department of Biology, The University of Western Ontario, London, ON, N6A 5B7, Canada.
Sangita
S
Sahni
Department of Biology, The University of Western Ontario, London, ON, N6A 5B7, Canada.
Bishun D
BD
Prasad
Commonwealth Scientific and Industrial Research Organization, Agriculture, PO Box 1600, Canberra, ACT 2601, Australia.
Qing
Q
Liu
Department of Biology, The University of Western Ontario, London, ON, N6A 5B7, Canada.
Vojislava
V
Grbic
National Research Council Canada, Plant Biotechnology Institute, 110 Gymnasium Place, Saskatoon, SK S7N 0W9, Canada.
Andrew
A
Sharpe
Commonwealth Scientific and Industrial Research Organization, Agriculture, PO Box 1600, Canberra, ACT 2601, Australia.
Surinder P
SP
Singh
Department of Biology, The University of Western Ontario, London, ON, N6A 5B7, Canada.|School of Environmental and Rural Sciences, University of New England, Armidale, NSW 2350, Australia.
Priti
P
Krishna
D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000096:biosynthesis / Q000235:genetics*; D001203:Ascomycota / Q000502:physiology; D053898:Biosynthetic Pathways; D029688:Brassica napus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D060406:Brassinosteroids / Q000096:biosynthesis; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics*; D003681:Dehydration / Q000235:genetics / Q000378:metabolism; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D024861:Genetic Enhancement; D010935:Plant Diseases / Q000382:microbiology; D010938:Plant Oils / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D059467:Transcriptome
C111451:AT3G50660 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D010938:Plant Oils; D003577:Cytochrome P-450 Enzyme System