TY - JOUR

T1 - Plant responses to co-occurring heat and water deficit stress

T2 - A comparative study of tolerance mechanisms in old and modern wheat genotypes

AU - Akula, Nagashree N.

AU - Abdelhakim, Lamis

AU - Knazovický, Mikulás

AU - Ottosen, Carl Otto

AU - Rosenqvist, Eva

N1 - Publisher Copyright: © 2024 The Authors

PY - 2024

Y1 - 2024

N2 - Global climate change increases the likelihood of co-occurrence of hot and dry spells with increased intensity, frequency, and duration. Studying the impact of the two stresses provide a better understanding of tolerance mechanisms in wheat, and our study was focused on revealing plant stress responses to different severities of combined stress at two phenophases in old and modern wheat genotypes. During the stem elongation and anthesis stages, plants were exposed to four treatments: control, deficit irrigation, combined heat, and deficit irrigation at 31 °C (HD31) and 37 °C (HD37). The modern genotypes were less affected by deficit irrigation at stem elongation as they maintained higher photosynthesis, stomatal conductance, and leaf cooling than old genotypes. When the HD37 stress was imposed during anthesis, the modern genotypes exhibited superior performance compared to the old, which was due to their higher photosynthetic rates resulting from improved biochemical regulation and a higher chlorophyll content. The plant responses varied during two phenophases under the combined stress exposure. Genotypes subjected to HD37 stress during stem elongation, photosynthesis was mainly controlled by stomatal regulation, whereas at anthesis it was predominated by biochemical regulation. These findings contribute to a deeper comprehension of plant tolerance mechanisms in response to different intensities of co-occurring hot and dry weather conditions.

AB - Global climate change increases the likelihood of co-occurrence of hot and dry spells with increased intensity, frequency, and duration. Studying the impact of the two stresses provide a better understanding of tolerance mechanisms in wheat, and our study was focused on revealing plant stress responses to different severities of combined stress at two phenophases in old and modern wheat genotypes. During the stem elongation and anthesis stages, plants were exposed to four treatments: control, deficit irrigation, combined heat, and deficit irrigation at 31 °C (HD31) and 37 °C (HD37). The modern genotypes were less affected by deficit irrigation at stem elongation as they maintained higher photosynthesis, stomatal conductance, and leaf cooling than old genotypes. When the HD37 stress was imposed during anthesis, the modern genotypes exhibited superior performance compared to the old, which was due to their higher photosynthetic rates resulting from improved biochemical regulation and a higher chlorophyll content. The plant responses varied during two phenophases under the combined stress exposure. Genotypes subjected to HD37 stress during stem elongation, photosynthesis was mainly controlled by stomatal regulation, whereas at anthesis it was predominated by biochemical regulation. These findings contribute to a deeper comprehension of plant tolerance mechanisms in response to different intensities of co-occurring hot and dry weather conditions.

KW - Chlorophyll fluorescence

KW - Climate change stress

KW - Deficit irrigation

KW - Gas exchange

KW - Heat

KW - Spring wheat

U2 - 10.1016/j.plaphy.2024.108595

DO - 10.1016/j.plaphy.2024.108595

M3 - Journal article

C2 - 38581807

AN - SCOPUS:85189494463

VL - 210

JO - Plant Physiology and Biochemistry

JF - Plant Physiology and Biochemistry

SN - 0981-9428

M1 - 108595

ER -