Genotypic variation in drought stress response and subsequent recovery of wheat (Triticum aestivum L.)

Abstract

Three wheat (Triticum aestivum L.) genotypes, Sadovo, Katya and Prelom, with different tolerance to drought were comparatively evaluated in terms of leaf respiratory responses to progressing dehydration and consecutive rewatering. Under drought stress, the respiration of all varieties gradually decreased, as the drought-tolerant Katya showed the most pronounced decline at earlier stages of dehydration. When water stress intensified, this genotype gave relatively stable respiration rates compared with the drought-sensitive varieties. Additionally, dehydrated Katya leaves displayed lower stomatal conductance and higher photosynthesis values, which resulted in greater water use efficiency during the dehydration period. Combination of drought stress and short-term changes in leaf temperature also induced genotype-specific response that differed from the response to drought only. Over the whole temperature range, the leaves of Katya exposed to dehydration for 14 days, showed higher respiration rates compared to the drought-sensitive varieties. The sensitive varieties maintained higher respiration rates under control conditions and mild dehydration, and very low rates under severe drought. In Katya, respiration and photosynthesis were fully restored from the stress within the first day of rewatering. The drought-sensitive genotypes displayed a considerably slower recovering capacity. The results are discussed in terms of possible physiological mechanisms underlying plant tolerance to drought.

Drought stress and carbon assimilation in a warming climate: Reversible and irreversible impacts

“…The response of different genotypes of the same crop species to drought or heat periods may vary in wide range (Vassileva et al, 2009(Vassileva et al, , 2011(Vassileva et al, , 2012Erice et al, 2010Erice et al, , 2011Yin et al, 2010 ;Parry et al, 2011;Prior et al, 2011;Cao et al, 2014 ;Habash et al, 2014;Topbjerg et al, 2014;Acuna-Galinda et al, 2015 ;Lopes et al, 2015;Wani et al, 2015;Wehner et al, 2015). This is the basis for breeding of crop varieties with a better performance under abiotic stresses.…”

“…Such protective mechanisms are relevant for stress phases, but may also be relevant for the performance of plants after a stress period by influencing the velocity and the degree of recovery (Gallé and Feller, 2007;Gallé et al, 2007;Vassileva et al, 2011).…”

“…Therefore the integral performance during the whole season is relevant for a comprehensive evaluation of a species or of a genotype. Net photosynthesis does not only depend on photosynthetic electron transport and Calvin cycle activity, since carbon losses via decarboxylation processes also contribute to the overall performance (Wingler et al, 1999;Haupt-Herting et al, 2001;Noctor et al, 2002;Bai et al, 2008;Rivero et al, 2009;Vassileva et al, 2009Vassileva et al, , 2011. The impact of heat and drought on respiration is also crucial for the carbon balance and should be considered when comparing genotypes (Flexas et al, 2006;Vassileva et al, 2011).…”

Extreme climatic events: impacts of drought and high temperature on physiological processes in agronomically important plants

“…These regional climatic extremes (Gilgen and Buchmann, 2009) are ecologically and economically relevant for agriculture and forestry (IPCC, 2012;Smith and Gregory, 2013;Nair, 2014). The susceptibility to abiotic stresses may differ considerably among species or varieties of a crop (Yordanov et al, 2000;Simova-Stoilova et al, 2009;Vassileva et al, 2011;Chen et al, 2012;Wishart et al, 2014). Therefore, the selection of suitable genotypes and breeding of less susceptible varieties could reduce negative effects of extreme climate events on plant productivity (Neumann, 2008;Mir et al, 2012;Jogaiah et al, 2013), which is particularly important for the annual crops.…”

“…The apparent significance of stress period for the crop productivity does not rule out the fact that subsequent recovery stages are equally crucial for a proper evaluation of the overall performance (Subramanian and Charest, 1998;Vassileva et al, 2011). The progression and duration of stress, plant developmental stage and other biotic and abiotic factors may influence the stress response.…”