Articles
PRIMING FOR TRANSPLANT STRESS RESISTANCE IN IN VITRO PROPAGATION VIA PLANTLET BACTERIZATION
Article number
748_5
Pages
65 – 75
Language
English
Abstract
Production of high quality, vigorous tissue culture-derived transplants requires efficient means to enhance their post-transplant ability for water management, photosynthesis and resistance to pathogens.
Although there is increasing evidence that beneficial bacteria associated with plants are able to induce host resistance to abiotic and biotic stress, they have not been used in commercial micropropagation.
We have documented that some of these beneficial bacteria can be co-cultured in vitro with plant explants and colonize the emerging plantlets.
The bacterized plantlets appear more vigorous and withstand transplant stress better than non-inoculated controls.
Their metabolism becomes pre-sensitised, or primed to respond more quickly and to a higher degree to environmental challenges.
A specific endophyte, Burkholderia phytofirmans strain PsJN, isolated from surface-sterilized onion roots, has conveyed improved growth and development to potato, tomato, sweet pepper, cucumber and grape plantlets.
These primed plants have also exhibited improved performance under stress, including disease resistance to fungal pathogens.
The phenotype of bacterized plantlets in vitro is distinct (shorter, more branched and thicker roots, greater root and shoot biomass and more lignified and sturdier stems) and the clonal propagules or seedlings have improved survival and vigor after transplanting.
However, the capacity for this beneficial plant-microbial interaction varies among cultivars and seems to be related to a population threshold of endophytic bacteria established in planta.
To fully harness the potential benefits of bacterial endophytes for in vitro propagation we need to understand genetic determinants of the host-inoculant interaction under various environmental conditions.
We have initiated such research using a unique population of sibling monoploid potatoes (derived by anther culture from a single heterozygous clone of adapted Solanum phureja and selected for high vigor) that differ for their ability to respond to PsJN. An ultimate goal of this research approach is the development of value added tissue culture propagules as a component of sustainable plant production system.
Although there is increasing evidence that beneficial bacteria associated with plants are able to induce host resistance to abiotic and biotic stress, they have not been used in commercial micropropagation.
We have documented that some of these beneficial bacteria can be co-cultured in vitro with plant explants and colonize the emerging plantlets.
The bacterized plantlets appear more vigorous and withstand transplant stress better than non-inoculated controls.
Their metabolism becomes pre-sensitised, or primed to respond more quickly and to a higher degree to environmental challenges.
A specific endophyte, Burkholderia phytofirmans strain PsJN, isolated from surface-sterilized onion roots, has conveyed improved growth and development to potato, tomato, sweet pepper, cucumber and grape plantlets.
These primed plants have also exhibited improved performance under stress, including disease resistance to fungal pathogens.
The phenotype of bacterized plantlets in vitro is distinct (shorter, more branched and thicker roots, greater root and shoot biomass and more lignified and sturdier stems) and the clonal propagules or seedlings have improved survival and vigor after transplanting.
However, the capacity for this beneficial plant-microbial interaction varies among cultivars and seems to be related to a population threshold of endophytic bacteria established in planta.
To fully harness the potential benefits of bacterial endophytes for in vitro propagation we need to understand genetic determinants of the host-inoculant interaction under various environmental conditions.
We have initiated such research using a unique population of sibling monoploid potatoes (derived by anther culture from a single heterozygous clone of adapted Solanum phureja and selected for high vigor) that differ for their ability to respond to PsJN. An ultimate goal of this research approach is the development of value added tissue culture propagules as a component of sustainable plant production system.
Publication
Authors
J. Nowak, R.E. Veilleux, J. Nowak, S. Turgeon
Keywords
in vitro co-culture, Burkholderia phytofirmans strain PsJN, enhanced stress tolerance, genotypic effect
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