Canadian Forest Service Publications
Plant growth regulators for enhancing revegetation success in reclamation: A review. 2018. Small, C.C.; Degenhardt, D. Ecological Engineering 118(2018):43-51.
Issued by: Northern Forestry Centre
Catalog ID: 39689
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Plant growth regulators (PGRs) are natural hormones and synthetic hormone analogues. Types of PGRs reviewed in this paper include auxins, gibberellins, cytokinins, ethylene, abscisic acid, brassinosteroids and jasmonates. At low concentrations, PGRs have the capacity to influence cell division, cell expansion, and cell structure and function, in addition to mediating environmental stress. The direct application to plant roots, shoots, leaves, buds and flowers has been shown to increase resilience to abiotic and biotic stress, break seed dormancy, improve drought tolerance and water use efficiency, improve temperature tolerance, improve nitrogen use efficiency, promote shoot elongation and generation, increase shoot and root mass, stimulate root growth and lateral root development, and promote photosynthesis. PGR products are commonly used throughout agriculture, viticulture, and horticulture to improve plant growth and crop yield under non-ideal soil and environmental conditions. PGR products have yet to be trialed and registered for reclamation purposes in Canada. Their use may improve reclamation success by enhancing growth of slow-growing native plants and transplanted seedlings and cuttings; promoting the redevelopment of soil bacterial communities (including rhizobacteria); enhancing plant growth under environmentally stressful conditions; and, increasing adaptation and resiliency during climate change. There are significant opportunities for seed development, plant propagation and bioengineering in North America for both greenhouse-based and field-based applications. If successful, PGR use on native plants may improve the ecological function of disturbed lands by reducing the timeframe for reclamation and facilitating the achievement of reclamation end goals.
Plain Language Summary
Governments, industry, and environmental service providers are always looking for better ways to return land to its natural state after it has been used for industrial purposes, such as mining. One challenge for reclamation projects is that it is difficult to grow high-quality seedlings of native plants from seed and then to get the seedlings to thrive in reclaimed soils. Plant growth regulators are natural and synthetic versions of hormones produced by plants, which regulate how plants grow and function. Some of them might be able to improve the germination and growth of native plant seedlings in greenhouses and to enhance the survival of the seedlings after they are transplanted to reclaimed sites. In this article the authors review the five major types of plant growth regulators and the scant research on their use for reclamation. There are significant opportunities to use plant growth regulators to reduce the time frame for reclamation and to increase the likelihood that reclamation end goals will be met. To date, however, no plant growth regulators have been tested or registered for reclamation purposes in Canada.