Crops face numerous abiotic and biotic stresses throughout their lifetimes. These environmental pressures are intensifying in the form of extreme weather events, drought, salinity, invasive insects and pathogens, and other stressors in a changing climate. The need for improving crop productivity and quality with enhanced resource use efficiencies (e.g., water, nitrogen) has increased immensely to meet the demand for providing food, energy, and other goods and services for a rapidly increasing global population.
A growing volume of recent scientific research is devoted to assessing climate change impacts and developing adaptation strategies in agriculture for achieving food security in future climates. Many of these studies have focused on staple food and other major crops such as rice, maize, wheat, soybean, and cotton. By contrast, relatively little attention has been paid to specialty crops in light of climate change (Fig. 1A). A thorough assessment of climate change impacts on specialty crops, coupled with targeted development of adaptation strategies, is urgently needed. Research on environmental stress physiology can provide fundamental knowledge and forms the basis for tools to develop climate adaptation strategies in horticulture.
An impressive legacy of environmental stress research in horticultural crops has spawned numerous fundamental discoveries and a wealth of knowledge that can be directly or indirectly applied to climate change research. For example, over 150 studies have been published on crop heat stress in specialty crops in horticultural journals according to our literature search in the Web of Science database (Thompson Reuters, New York, NY) as of Dec. 2011 (Fig. 1B). Many of these articles did not specify “climate change” or “global warming” in their keywords list (Fig. 1A). However, their findings on crop heat stress have direct implications for climate change research and are likely to provide critical insights for successful climate adaptations in agriculture. Another example of the relevancy of horticultural research to climate change science comes from a plethora of carbon dioxide (CO2) enrichment studies in the controlled environment whose findings have built the foundations of further elevated CO2 studies (e.g., Jiao and Grodzinski, 1998; Kimball, 1983; Mortensen, 1987; Mortensen and Moe, 1983; Prior et al., 2011).
Horticultural scientists are working to improve crop stress tolerance through breeding (both conventional and molecular), genetic engineering, and other means involving changes in crop genetics (e.g., Bassett et al., 2011; Wisniewski et al., 2011). These approaches are valuable methods, especially as long-term adaptive solutions to climate change. Equally valuable approaches, particularly for short-term climate adaptations, are likely to include selecting appropriate cultivars or species, adopting cultural practices for reducing crop environmental stress, and exploring novel tools and approaches for mitigating plant stress in a changing climate.
In conjunction with crop improvement efforts, many critical advances have been made in developing methods to diagnose, monitor, and mitigate crop environmental stresses. These physiological and ecological methods complement genetic approaches for improving stress tolerances in crops. The colloquium sponsored by the ASHS STRS Working Group served as a forum to bring together several of these emerging, novel methods for diagnosing, monitoring, and mitigating crop environmental stress. An emphasis was placed on horticultural, physiological, and ecological approaches that bear direct implications in climate change research. The specific aims of this colloquium were to introduce: 1) novel and emerging methods for early detection and assessment of plant stress; 2) novel and emerging methods for mitigating plant stress; and 3) applications of these methods in horticulture.
Accordingly, the colloquium consisted of two main themes: 1) stress diagnostics; and 2) stress mitigation. The stress diagnostics addressed in the colloquium represent recent advances in detecting and diagnosing crop stresses at leaf, whole-plant, or canopy scales. In the stress mitigation section, authors presented new and emerging techniques for mitigating the physiological impacts of environmental stresses and their application to horticultural crops.
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Bunce, J. 2012 Using new gas exchange methods to estimate mesophyll conductance and non-stomatal inhibition of photosynthesis caused by water deficits HortScience 47 687 690
Bunce, J.A. 2009 Use of the response of photosynthesis to oxygen to estimate mesophyll conductance to carbon dioxide in water-stressed soybean leaves Plant Cell Environ. 32 875 881
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Glenn, D.M. 2012b The mechanisms of plant stress mitigation by kaolin-based particle films and applications in horticultural and agricultural crops HortScience 47 710 711
Jiao, J. & Grodzinski, B. 1998 Environmental influences on photosynthesis and carbon export in greenhouse roses during development of the flowering shoot J. Amer. Soc. Hort. Sci. 123 1081 1088
Jithesh, M.N., Wally, O.S.D., Manfield, I., Critchley, A.T., Hiltz, D. & Prithiviraj, B. 2012 Analysis of seaweed extract induced transcriptome leads to identification of a negative regulator of salt tolerance in Arabidopsis HortScience 47 704 709
Merchant, A. 2012 Developing phloem δ13C and sugar composition as indicators of water deficit in Lupinus angustifolius HortScience 47 691 696
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Redman, R.S., Kim, Y.O., Woodward, C.J.D.A., Greer, C., Espino, L., Doty, S.L. & Rodriguez, R.J. 2011 Increased fitness of rice plants to abiotic stress via habitat adapted symbiosis: A strategy for mitigating impacts of climate change PLoS One 6 e14823
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Rosati, A., Metcalf, S.G., Buchner, R.P., Fulton, A.E. & Lampinen, B.D. 2007 Effects of kaolin application on light absorption and distribution, radiation use efficiency and photosynthesis of almond and walnut canopies Ann. Bot. (Lond.) 99 255 263
Wisniewski, M., Norelli, J., Bassett, C., Artlip, T. & Macarisin, D. 2011 Ectopic expression of a novel peach (Prunus persica) CBF transcription factor in apple (Malus ×domestica) results in short-day induced dormancy and increased cold hardiness Planta 233 971 983
Woodward, C., Hansen, L., Beckwith, F., Redman, R.S. & Rodriguez, R.J. 2012 Symbiogenics: An epigenetic approach to mitigating impacts of climate change on plants HortScience 47 699 703