A simple and holistic approach to alleviate biotic and abiotic stresses in canola through silicon (Si) uptake
Date: September 2022
Term: 3 years
Status: Complete
Researcher(s): Richard Belanger and P. Isenring, Laval University; W.G.D. Fernando, University of Manitoba; H.J. Kronzucker, University of Melbourne
SaskCanola Investment: $11,500
Total Project Cost: $614,000
Funding Partners: NSERC, Fairgreen
Grower Benefits
Linking Silicon (Si) fertilization to Si-enhanced canola varieties could improve yield, reduce serious disease impacts of blackleg, clubroot and sclerotina, and limit damages such as drought stress induced by climate change.
Researchers discovered a novel molecular-genetic determinant of Si-permeability in specific membrane channel proteins, which helps to understand why some species accumulate Si and others do not.
Researchers successfully transformed the model species Arabidopsis thaliana or thale cress, a close relative of canola, by incorporating two important genes for high capacity Si-transport and Si-accumulation into the genome.
Preliminary results of stress resiliency and Si-accumulation studies are very promising, and will inform future attempts at transforming high-value crops, such as canola, which currently lack in Si-accumulating traits.
Through these studies, researchers also gained considerable insight into the prophylactic mechanisms of Si fertilization. The study results have been used by Canadian Wollastonite to facilitate registration of silicon fertilizers.
Project Description
Increasing environmental stress resilience to improve growth and yield is important for canola production in Canada. Silicon (Si) is an important nutrient known to improve stress resilience to a number of biotic and abiotic stresses that reduce crop productivity to those plants that can readily absorb it. In this study, researchers wanted to better understand the underlying molecular-genetic and physiological mechanisms governing Si absorption in plants, and to attempt to bioengineer crops like canola otherwise incapable with Si-accumulating traits. Preliminary results of the stress resiliency studies are very promising, and will help in transforming Si-transport capabilities in canola. Through this project, researchers also gained considerable insight into the prophylactic mechanisms of Si fertilization. For canola growers, linking Si fertilization to Si-enhanced canola varieties could improve yield, reduce serious disease impacts of blackleg, clubroot and sclerotina and limit damages such as drought stress induced by climate change.
Increasing environmental stress resilience to improve growth and yield is important for canola production in Canada, which exceeds 20 million acres annually. Silicon (Si) is an important but elusive plant mineral nutrient known to improve stress resilience to a number of biotic and abiotic stresses that reduce crop productivity to those plants that can readily absorb it. Plants absorb Si from soils in the form of silicic acid (Si(OH)4) through Lsi1 transport channels from soil to root cells, and Lsi2 transport from root cells to xylem to aerial parts.
In this study, researchers wanted to better understand the underlying molecular-genetic and physiological mechanisms governing Si absorption in plants, and to attempt to bioengineer crops otherwise incapable with Si-accumulating traits in order to increase environmental stress resilience and thus improve growth and yield. The identification of molecular players controlling Si absorption in high Si-accumulating plant species, and introgressing them into canola through genetic transformation, would represent an innovative approach to achieve these goals.
Project objectives were to determine canola's natural ability to absorb Si genetically and phenotypically; to screen canola germplasm and other closely related species for their ability to absorb Si through genome-wide association studies (GWAS); and to improve the natural ability of canola to absorb Si through natural or transformation means. Researchers also wanted to evaluate the potential of Si to protect against blackleg, clubroot and sclerotinia diseases, and to quantify the benefits of Si absorption in Si-competent canola material for improved disease resistance.
For the experiments, researchers conducted structure-function studies in the Xenopus laevis oocyte expression system to identify residues in both Lsi1 and Lsi2 that are important in determining Si transport activity, to generate conservative Lsi1 and Lsi2 mutants that are endowed with high Si transport activity (Lsi1HS and Lsi2HS) and to study the protective role of these mutants in planta under various stresses. Several Lsi1 and Lsi2 plant transgenes were generated and subjected to phenotyping studies for Si absorption and resistance to stress, and additional structure-function studies were conducted using a variety of computational tools. Several Si fertilization strategies were tested in collaboration with industry partners, which included testing different concentrations and particle sizes of wollastonite to determine the conditions for optimizing Si uptake by the plants.
Experiments were also conducted to determine the Si-uptake capacity and stress resiliency of these high-Si transgene plants. A biotic stress resiliency experiment was conducted with Leptophaeria maculans, which causes blackleg disease, to measure disease development and Si accumulation in the plants. Abiotic stress experiments for drought stress evaluated plant response to water stress and Si accumulation.
As a result of the experiments, researchers discovered a novel molecular-genetic determinant of Si-permeability in specific membrane channel proteins, which helps to understand why some species accumulate Si and others do not. Researchers successfully transformed the model species Arabidopsis thaliana or thale cress, a close relative of canola, by incorporating two important genes for high capacity Si-transport and Si-accumulation into the genome. This successful transfer of the protective effect to Si-impermeable plants contributes to a better understanding of Si absorption mechanisms, and also informs biotechnological applications to introduce the superior Si-transport capabilities into low-Si-accumulating species. Preliminary results of the stress resiliency studies are very promising, and will help in transforming Si-transport capabilities in canola. Through this project, researchers also gained considerable insight into the prophylactic mechanisms of Si fertilization.
Overall, the study results will inform future attempts at transforming high-value crops, such as canola, which currently lack in Si-accumulating traits. By successfully completing the development of Si-enhanced canola varieties to benefit from fertilization through a simple manipulation of Si transporters would have a significant impact on canola production. Linking Si fertilization to Si-enhanced canola varieties could improve yield, reduce serious disease impacts of blackleg, clubroot and sclerotina and limit damages such as drought stress induced by climate change.
Scientific Publications:
Coskun, D., Deshmukh, R., Shivaraj, S.M., Isenring, P., Bélanger, R.R. (2021). Lsi2: A black box in plant silicon transport. Plant and Soil 466, 1-20. https://doi.org/10.1007/s11104-021-05061-1.
Noronha, H., Silva, A., Mitani-Ueno, N., Conde, C., Sabir, F., Prista, C., Soveral, G., Isenring, P., Ma, J.F., Bélanger, R.R., Gerós, H. (2020). The grapevine NIP2;1 aquaporin is a silicon channel. Journal of Experimental Botany 71, 6789-6798. https://doi.org/10.1093/jxb/eraa294.
Deshmukh, R., Sonah, H., Bélanger, R.R. (2020). New evidence defining the evolutionary path of aquaporins regulating silicon uptake in land plants. Journal of Experimental Botany 71, 6775-6788. https://doi.org/10.1093/jxb/eraa342.
Shivaraj, S.M., Deshmukh, R., Sonah, H., Bélanger, R.R. (2019). Identification and characterization of aquaporin genes in Arachis duranensis and Arachis ipaensis genomes, the diploid progenitors of peanut. BMC Genomics 20, 222. https://doi.org/10.1186/s12864-019-5606-4.
Coskun, D., Deshmukh, R., Sonah, H., Shivaraj, S.M., Frenette-Cotton, R., Tremblay, L., Isenring, P., Bélanger, R.R. (2019). Si permeability of a deficient Lsi1 aquaporin in tobacco can be enhanced through a conserved residue substitution. Plant Direct 3, e00163. https://doi.org/10.1002/pld3.163.
Coskun, D., Deshmukh, R., Sonah, H., Menzies, J.G., Reynolds, O., Ma, J.F., Kronzuker, H.J., Bélanger, R.R. (2019). In defence of the selective transport and role of silicon in plants. New Phytologist 223, 514-516. https://doi.org/10.1111/nph.15764.
Coskun, D., Deshmukh, R., Sonah, H., Menzies, J.G., Reynolds, O., Ma, J.F., Kronzucker, H.J., Bélanger, R.R. (2019). The controversies of silicon’s role in plant biology. New Phytologist 221, 67-85. https://doi.org/10.1111/nph.15343.
Bokor, B., Soukup, M., Vaculík, M., Vd’ǎcńy, P., Weidinger, M., Lichtscheidl, I., Vávrová, S., Šoltys, K., Sonah, H., Deshmukh, R., Bélanger, R.R., White, P.J., El- Serehy, H. A., Lux, A. (2019). Silicon uptake and localisation in date palm (Phoenix dactylifera) - A unique association with sclerenchyma. Frontiers in Plant Science 10, 988. https://doi.org/10.3389/fpls.2019.00988.
Garneau, A.P., Marcoux, A.-A., Frenette-Cotton, R., Bélanger, R.R. and Isenring, P. (2018). A new gold standard approach to characterize the transport of Si across cell membranes in animals. Journal of Cell Physiology 233, 6369-6376. https://doi.org/10.1002/jcp.26476.