Maize and heat stress: Physiological, genetic, and molecular insights

• Published in: The plant genome Vol. 17; no. 1; pp. e20378 - n/a
• Main Authors: Djalovic, Ivica, Kundu, Sayanta, Bahuguna, Rajeev Nayan, Pareek, Ashwani, Raza, Ali, Singla‐Pareek, Sneh L., Prasad, P. V. Vara, Varshney, Rajeev K.
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01-03-2024; Wiley
• Subjects: Abortion; Agricultural production; Animal reproduction; Carbon; Climate change; Corn; CRISPR; Crop improvement; Crop production; Crop yield; Cultivars; Enzymes; Food security; Food supply; Genetic diversity; Genome-wide association studies; Genomes; Genotypes; Greenhouse gases; Growth models; Heat; Heat shock factors; Heat shock proteins; Heat stress; Nutrition; Physiology; Plant breeding; Population genetics; Quantitative trait loci; Soil moisture; Solar radiation; Temperature; Temperature effects; Vapor pressure; Water content; United States > US; Africa
• ISSN: 1940-3372; 1940-3372
• DOI: 10.1002/tpg2.20378

Global mean temperature is increasing at a rapid pace due to the rapid emission of greenhouse gases majorly from anthropogenic practices and predicted to rise up to 1.5°C above the pre‐industrial level by the year 2050. The warming climate is affecting global crop production by altering biochemical, physiological, and metabolic processes resulting in poor growth, development, and reduced yield. Maize is susceptible to heat stress, particularly at the reproductive and early grain filling stages. Interestingly, heat stress impact on crops is closely regulated by associated environmental covariables such as humidity, vapor pressure deficit, soil moisture content, and solar radiation. Therefore, heat stress tolerance is considered as a complex trait, which requires multiple levels of regulations in plants. Exploring genetic diversity from landraces and wild accessions of maize is a promising approach to identify novel donors, traits, quantitative trait loci (QTLs), and genes, which can be introgressed into the elite cultivars. Indeed, genome wide association studies (GWAS) for mining of potential QTL(s) and dominant gene(s) is a major route of crop improvement. Conversely, mutation breeding is being utilized for generating variation in existing populations with narrow genetic background. Besides breeding approaches, augmented production of heat shock factors (HSFs) and heat shock proteins (HSPs) have been reported in transgenic maize to provide heat stress tolerance. Recent advancements in molecular techniques including clustered regularly interspaced short palindromic repeats (CRISPR) would expedite the process for developing thermotolerant maize genotypes.
Core Ideas
Maize is an important food, nutrition, and climate security crop around the world.
Heat stress negatively impacts the growth, development, and yield of maize.
Genotypes respond to heat stress at physiological, biochemical, and molecular levels.
Current knowledge and advances in traits and genotypic responses are discussed.