Sensitivity of fast chlorophyll fluorescence parameters to combined heat and drought stress in wheat genotypes

Abstract

This study aimed to characterise the specific phenotypic responses and the sensitivity of photosynthetic parameters to progressive drought in modern wheat genotypes. In pot experiments, we tested eight wheat genotypes (Triticum sp.) that differed in ploidy level and country of origin. Water stress was simulated by the restriction of irrigation, which led to a decreased leaf relative water content of up to 70%. During gradual dehydration, changes in the structure and function of photosystem II (PSII) were analysed using the fluorescence parameters derived from fast fluorescence kinetics (OJIP transient). The results indicated that a group of JIP test-based parameters demonstrated sensitivity to drought, including genotype-specific responses. Severe drought stress led to a decrease in the photochemical efficiency of PSII (Fv/Fm), a reduction in the number of active PSII reaction centers (RC/ABS) and a decrease in parameters, indicating overall photochemical performance at the PSII level (performance indices PIabs and PItot). These findings demonstrate that the approaches used in our experiments were useful and reliable in monitoring the physiological responses of individual varieties of wheat exposed to stress conditions, and they have application potential as selection criteria in crop breeding. The contribution of the high-temperature effects on the photochemical responses under water deficit conditions is also discussed.

Comparative Study of Photosynthesis Performance of Herbicide-Treated Young Triticale Plants during Drought and Waterlogging Stress

“…Similar changes in fluorescence parameters were observed in wheat plants subjected to drought [30,31]. PI total (Figure 5B) utilization of light energy because of dissipation through heat, which is in accordance with earlier reports [32]. This is evidenced by the increased F 0 /F m ratio (Figure 5B) in the drought-treated plants during prolonged water deficit.…”

Genome-wide association mapping for component traits of drought and heat tolerance in wheat

“…CT influences the stay-green of leaves, a drought-adaptive trait characterized by a distinct green leaf phenotype during grain filling during terminal drought (Borrell et al, 2014 ). Drought and heat stress have a significant impact on leaf chlorophyll content (Barboričová et al, 2022 ). The level of chlorophyll in flag leaves is measured by a portable equipment (SPAD meter), which is thought to be a sign of ‘stay-green' or delayed senescence (Lopes et al, 2012 ).…”

Water Deficit Severity during the Preceding Year Determines Plant Tolerance to Subsequent Year Drought Stress Challenges: A Case Study in Damask Rose

“…To evaluate plant photosynthetic performance, the ratio of variable to maximum chlorophyll fluorescence (F v /F m ) was recorded [25,26]. Measurements were carried out by employing an analyzer fluorimeter (Pocket PEA, Hansatech Instruments, King's Lynn, Norfolk, UK).…”

“…For assessing the in vivo adaptive responses of the photosynthetic system (especially photosystem II) to the cultivation regime, the kinetics of chlorophyll fluorescence induction were further determined. In this context, a polyphasic chlorophyll fluorescence induction curve (O-J-I-P-transient) was performed [25,26]. The computations and applied protocol are provided in Moosavi-Nezhad et al (2021) [25].…”