Heat stress effects on the reproductive physiology and yield of wheat

Abstract

Climate change is adversely affecting wheat yields as the associated rising temperatures damage its reproductive physiology. Heat stress affects wheat at various stages of growth, but flowering and reproductive phases are the most sensitive to high temperatures as flower opening usually occurs in cooler environments. Heat stress at meiosis causes ovule and pollen sterility along with anther dehiscence. During pollen development, temperatures >30°C cause pollen abortion. At anthesis, heat stress limits resource translocation to developing grain, resulting in small grain and low yields. During grain development, heat stress shortens the grain-filling duration and decreases starch and protein accumulation due to reduced activity of grain biosynthesis enzymes and impaired flag leaf assimilatory efficiency and stem reserve mobilization. The development of heat-tolerant wheat genotypes through screening, selection and breeding using genetic engineering, exogenous application of osmoprotectants and agronomic approaches is a high priority. This review discusses the impact of heat stress on flower development and fertilization, grain development and reproductive failure in wheat and outlines strategies (i.e. breeding and selection, genetic engineering, molecular breeding and management) to improve heat tolerance in wheat.

Assessing the heat sensitivity of Urdbean (Vigna mungo L. Hepper) genotypes involving physiological, reproductive and yield traits under field and controlled environment

“…Of all the growth stages, reproductive stage is the most sensitive stage affected by negative impact of heat stress (Zinn et al, 2010). High temperature stress causes anomalies and malfunction in reproductive processes ranging from reduction in pollen germination (PGP) percentage, pollen viability percentage (PVP), malformation in ovule to inhibition in fertilization process in various crops, including rice (Xu et al, 2021), wheat (Ullah et al, 2022), chickpea (Bhandari et al, 2020;Devi et al, 2022), common bean (Silva et al, 2019;Soltani et al, 2019) and tomato (Gonzalo et al, 2021). High PGP and PVP values are indicators of efficient reproductive function leading to high pod and seed setting resulting in improved yield under heat stress (Firon et al, 2006;Pham et al, 2020).…”

Impacts, Tolerance, Adaptation, and Mitigation of Heat Stress on Wheat under Changing Climates

“…Wheat is most susceptible to elevated temperature stress especially during anthesis stage and less likely to recover if stressed at this critical stage [ 11 , 12 , 13 ]. HS can affect the growth and development of wheat through alteration of physio-bio-chemical processes, such as photosynthesis, respiration, oxidative damage, activity of stress-induced hormones, proteins and anti-oxidative enzymes, water and nutrient relations, and yield forming attributes (biomass, tiller count, grain number and size) upon exposure to temperatures above the optimum range [ 14 , 15 , 16 , 17 , 18 , 19 ].…”

Improvement of heat stress tolerance in soybean (Glycine max L), by using conventional and molecular tools

“…Heat stress impairs the metabolic pathways ( Kosová et al, 2011 ), which results in altered plant growth ( Kosová et al, 2011 ; Liu et al, 2014 ). Climate change is expected to increase the incidence and severity of summer heat waves ( Balfagón et al, 2022 ; Ullah et al, 2022 ), and the impact of heat stress on seed development will become more widespread ( Haider et al, 2022 ) and prolonged during current century ( Chebrolu et al, 2016 ; Sun et al, 2022 ). Episodes of heat waves are expected to increase in intensity in the coming time due to global warming and climate changes ( Balfagón et al, 2019 ; Ault, 2020 ; Grossiord et al, 2020 ).…”