Parental Drought-Priming Enhances Tolerance to Post-anthesis Drought in Offspring of Wheat

Abstract

Drought is the major abiotic stress that decreases plant water status, inhibits photosynthesis, induces oxidative stress, restricts growth and finally lead to the reduction of wheat yield. It has been proven that drought priming during vegetative growth stage could enhance tolerance to drought stress at grain filling in wheat. However, whether drought priming imposed at grain filling in parental plants could induce drought tolerance in the offspring is not known. In this study, drought priming was successively applied in the first, the second and the third generation of wheat to obtain the plants of T1 (primed for one generation), T2 (primed for two generations), T3 (primed for three generations). The differently primed plants were then subjected to drought stress during grain filling in the fourth generation. Under drought stress, the parentally primed (T1D, T2D, T3D) plants, disregarding the number of generations, showed higher grain yield, leaf photosynthetic rate and antioxidant capacity as well as lower O2•− release rate and contents of H2O2 and MDA than the non-primed (T0D) plants, suggesting that drought priming induced the transgenerational stress tolerance to drought stress. Moreover, the parentally primed plants showed higher leaf water status, which may result from the higher contents of proline and glycine betaine, and higher activities of Δ1-pyrroline-5-carboxylate synthetase (P5CS) and betaine aldehyde dehydrogenase (BADH), compared with the non-primed plants under drought stress. In addition, there was no significant difference among three generations under drought, and the drought priming in parental generations did not affect the grain yield of the offspring plants under control condition. Collectively, the enhanced accumulation of proline and glycine betaine in the parentally primed plants could have played critical roles in parental priming induced tolerance to drought stress. This research provided a potential approach to improve drought tolerance of offspring plants by priming parental plants.

Double benefits of mechanical wounding in enhancing chilling tolerance and lodging resistance in wheat plants

“…Chlorophyll fluorescence parameters were detected in the latest fully expanded leaves from the top of the plants 24 h after chilling treatment using a portable chlorophyll fluorometer (PAM‐2500; Heinz Walz, Effeltrich, Germany) as previously described (Wang et al . ). The maximum efficiency of photosystem II (PSII) photochemistry when dark‐adapted ( F v / F m ) and the actual photochemical efficiency (ΦPSII) were measured after 30 min of full dark adaptation.…”

Targeting Glycinebetaine for Abiotic Stress Tolerance in Crop Plants: Physiological Mechanism, Molecular Interaction and Signaling

“…Drought priming of wheat seeds promoted drought tolerance in the progenies of the treated seeds [81]. Successive application of drought priming in three generations resulted in improved photosynthetic rate and antioxidant capacity in the offspring plants.…”

“…The physiological basis of such drought tolerance was attributed to higher BADH and Δ 1 -pyrroline-5-carboxylate synthase (P5CS) activities, leading to enhanced accumulation of GB and Pro in the offspring seedlings of the treated plants. Thus, GB acts as a crucial osmolyte, which promotes parental priming-induced drought tolerance [81]. Hydropriming and osmopriming of bread wheat seeds with 1.5% CaCl2 promoted trans-generational drought memory and improved salt tolerance due to increased accumulation of leaf GB and Pro.…”

“…The existence of a demethylated allele of P5CS was proposed even after removal of the stress cues indicating towards the development of stress memory [176]. Drought-and osmopriming-induced trans-generational drought tolerance (stress memory) mediated by GB has also been reported in wheat seedlings [81,82]. Thus, abiding by the current understanding, it would be better to relate GB and Pro as two synchronized arms of osmotic-stress response, which simultaneously cooperate under sub-optimal conditions.…”

Abscisic acid and hydrogen peroxide are involved in drought priming‐induced drought tolerance in wheat (Triticum aestivum L.)

“…Proline concentration was measured using the Ninhydrin method as described by Bates et al (1973), with minor modifications according to Wang et al (2018). Briefly, the last expanded leaves were freeze‐dried, then ground to a powder.…”