Effect of exogenously-applied abscisic acid, putrescine and hydrogen peroxide on drought tolerance of barley

Abstract

The objective of this study was to identify the effect of abscisic acid (ABA), putrescine (Put) and hydrogen peroxide (H2O2) foliar pre-treatment on drought tolerance of barley. Despite water limitation, ABA-sprayed plants preserved increased water content, photosynthetic efficiency of PSII (ΦPSII) and CO2 assimilation rate (Pn) compared to untreated stressed plants. The ABA-treated plants presented also the lowest rate of lipid peroxidation (MDA), lowered the rate of PSII primary acceptor reduction (1 – qP) and increased the yield of regulated energy dissipation (NPQ) with higher accumulation of PGRL1 (PROTON GRADIENT REGULATION LIKE1) protein. These plants preserved a similar level of photochemical efficiency and the rate of electron transport of PSII (ETRII) to the well-watered samples. The significantly less pronounced response was observed in Put-sprayed samples under drought. Additionally, the combined effects of drought and H2O2 application increased the 1 – qP and quantum yield of non-regulated energy dissipation in PSII (ΦNO) and reduced the accumulation of Rubisco activase (RCA). In conclusion, ABA foliar application allowed to balance water retention and preserve antioxidant capacity resulting in efficient photosynthesis and the restricted risk of oxidative damage under drought. Neither hydrogen peroxide nor putrescine has been able to ameliorate drought stress as effectively as ABA.

Withdrawn: Effects of water‐deficit stress and putrescine on performances, photosynthetic gas exchange, and chlorophyll fluorescence parameters of Salvia officinalis in two cutting times

“…Based on our results, the levels of PUT were not accompanied by a considerable corresponding shift in Pn and Gs, indicating that stomatal guidance was not the only agent for PUT-induced shifts in photosynthesis. Skowron et al (2021) also reached similar results. The decreased photosynthesis can be due to nonstomatal limitations including the stagnation in PSII activity and electron transport (das Neves et al, 2008;Xia et al, 2004).…”

Light Quality-Dependent Regulation of Non-Photochemical Quenching in Tomato Plants

“…The activity of catalase (CAT; EC 1.11.1.6) was determined as described elsewhere [ 34 ]. In brief, 20 μL enzyme extract was added to 405 μL 50 mM potassium phosphate buffer (pH 7.0) and 250 μL water.…”

Roles of Glutathione in Mediating Abscisic Acid Signaling and Its Regulation of Seed Dormancy and Drought Tolerance

“…In agreement with this, exogenous ABA or genetic mutations that lead to an increase in ABA level and signaling have been shown to improve the performance of plants under drought conditions. For example, treatment of plants with exogenous ABA or its synthetic analogues enhances drought tolerance in several species including wheat [83][84][85], barley [86], rice [87], sugarcane [88] and tea [89]. Furthermore, overexpression of the ABA biosynthetic gene NCED in tomato [90], tobacco, [91] and Petunia [92], and the ABA signaling gene PYL in rice [93] and tomato [94] results in improved tolerance to drought.…”