Heat Stress in Wheat during Reproductive and Grain-Filling Phases

• Published in: Critical reviews in plant sciences Vol. 30; no. 6; pp. 491 - 507
• Main Authors: Farooq, Muhammad, Bramley, Helen, Palta, Jairo A, Siddique, Kadambot H.M
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA CRC Press 01.11.2011; Taylor & Francis Group; Taylor & Francis; Taylor & Francis Ltd
• Subjects: Abiotic stress; Ambient temperature; Biological and medical sciences; Biotechnology; breeding; Breeding methods; chloroplasts; Climate change; Crop production; Crop yield; Dry matter; dry matter accumulation; filling period; Fundamental and applied biological sciences. Psychology; genetic engineering; genotype; Genotypes; grain yield; grain-filling; Heat; Heat resistance; heat shock proteins; heat stress; Heat tolerance; photosynthesis; Plant breeding; Plant reproduction; stay-green; stress tolerance; Temperature; terminal heat stress; Wheat; Monocotyledones; Grain filling; grain-filling; Review; Terminal; terminal heat stress; Stress; Stay-green; Triticum; Gramineae; Thermal shock; Angiospermae; Spermatophyta; Genetic engineering; Plant sciences; Photosynthesis; breeding
• ISSN: 0735-2689; 1549-7836; 1549-7836
• DOI: 10.1080/07352689.2011.615687

Ambient temperatures have increased since the beginning of the century and are predicted to continue rising under climate change. Such increases in temperature can cause heat stress: a severe threat to wheat production in many countries, particularly when it occurs during reproductive and grain-filling phases. Heat stress reduces plant photosynthetic capacity through metabolic limitations and oxidative damage to chloroplasts, with concomitant reductions in dry matter accumulation and grain yield. Genotypes expressing heat shock proteins are better able to withstand heat stress as they protect proteins from heat-induced damage. Heat tolerance can be improved by selecting and developing wheat genotypes with heat resistance. Wheat pre-breeding and breeding may be based on secondary traits like membrane stability, photosynthetic rate and grain weight under heat stress. Nonetheless, improvement in grain yield under heat stress implies selecting genotypes for grain size and rate of grain filling. Integrating physiological and biotechnological tools with conventional breeding techniques will help to develop wheat varieties with better grain yield under heat stress during reproductive and grain-filling phases. This review discusses the impact of heat stress during reproductive and grain-filling stages of wheat on grain yield and suggests strategies to improve heat stress tolerance in wheat.