Modern Breeding Strategies for Heat Tolerance in Solanaceae Crops

Global average temperature is rising at the rate of 0.3°C per decade. Heat stress or heat shock occurs when the temperature rises by 10–15°C above the optimum temperature. Elevated temperatures have a negative impact on agricultural output as they not only hinder flowering and fruit setting but also hinder fruit growth and maturity. The Solanaceae family is one of the most important families among plant species affected by heat stress. It includes 3000–4000 species, categorized into 90 genera. This chapter aims to assess the heat stress impact on Solanaceae plants, explores the strategies adopted by different plants against heat stress, and discusses advanced techniques like marker-assisted breeding and CRISPR-Cas technology to develop heat-tolerant cultivars. Heat stress causes overproduction of reactive oxygen species and oxidative stress, reduces photosynthesis, alters membrane fluidity, and undermines the overall stability of metabolic processes. It causes abortive male gametophytes, lowering fruit setting and reduced yield. Solanaceae plants have adopted to alter the metabolism of carbon absorption, remobilizing the starch reserve in chloroplasts and allowing them to survive stress periods. Any additional damage is avoided by releasing energy, sugars, and derived metabolites. Furthermore, a variety of heat stress-responsive proteins known as heat shock proteins (HSPs) and transcription factors (TFs) – heat stress-responsive TFs (HSFs) – are produced in response to severe temperature shocks. To mitigate heat stress, efforts are in practice to develop high-yielding heat-tolerant cultivars that are resistant to biotic and abiotic stress.