Heat stress in crop plants: its nature, impacts and integrated breeding strategies to improve heat tolerance

Abstract

Increasing severity of high temperature worldwide presents an alarming threat to the humankind. As evident by massive yield losses in various food crops, the escalating adverse impacts of heat stress (HS) are putting the global food as well as nutritional security at great risk. Intrinsically, plants respond to high temperature stress by triggering a cascade of events and adapt by switching on numerous stress-responsive genes. However, the complex and poorly understood mechanism of heat tolerance (HT), limited access to the precise phenotyping techniques, and above all, the substantial G 9 E effects offer major bottlenecks to the progress of breeding for improving HT. Therefore, focus should be given to assess the crop diversity, and targeting the adaptive/morpho-physiological traits while making selections. Equally important is the rapid and precise introgression of the HT-related gene(s)/QTLs to the heat-susceptible cultivars to recover the genotypes with enhanced HT. Therefore, the progressive tailoring of the heat-tolerant genotypes demands a rational integration of molecular breeding, functional genomics and transgenic technologies reinforced with the next-generation phenomics facilities.

The Effects of Night-time Temperatures on Physiological and Biochemical Traits in Rice

“…Knowledge of the physiological mechanisms associated with the interaction between genotype (G) and environment (E) has been one of the bottlenecks in breeding programs (Jha et al, 2014). In this regard, rice seedling studies have become an important tool to understand, in depth, the physiological mechanisms involved in plant tolerance to heat stress conditions during the last years (Xue et al, 2012;Sánchez-Reinoso et al, 2014).…”

“…On the other hand, plant acclimatization is also associated with genotype (Wahid et al, 2007;Jha et al, 2014). Several studies have shown that tolerant genotypes have a series of biochemical and physiological changes to cope with heat stress (Bita and Gerats, 2013;Kumar et al, 2016).…”

Variance components and heritability of yield and yield components of wheat under drought-stressed and non-stressed conditions

“…A decreasing trend is witnessed in the total production area and productivity of wheat and other long cycle cereal crops under dryland production conditions globally (Simelton et al, 2012;Lesk et al, 2016). This has been attributed to the combined effects of biotic and abiotic constraints, mainly drought and heat stresses (Jha et al, 2014). Wheat is a C3 crop that is sensitive to drought stress and high temperature conditions, especially during the post-anthesis growth stages, when the crop is often faced by erratic rainfall and prolonged dry spells (Alain et al, 2011;Ilker et al, 2011).…”

Assessing Effects of Temperature Change on Four Limonium Species from Threatened Mediterranean Salt-Affected Habitats

“…The response of plants to increasing temperatures depends on several factors, such as magnitude and duration of this increment, and also on plant characteristics. Many plant physiology aspects can be affected by thermal stress, including reserve immobilisation, protein denaturation, and alteration in the fluidity of membranes, enzyme inactivation, protein synthesis inhibition and impaired chlorophyll biosynthesis, among others (Levitt, 1980;Wahid et al, 2007;Hasanuzzaman et al, 2013;Jha et al, 2014). In addition, plant's phenological stage plays a relevant role in the magnitude of adverse effects that result from high temperature episodes.…”