Acetic acid positively modulates proline metabolism for mitigating PEG-mediated drought stress in Maize and Arabidopsis

Abstract

IntroductionOsmotic imbalance is one of the major consequences of drought stress, negatively affecting plant growth and productivity. Acetic acid has modulatory roles in osmotic balance in plants; however, the mechanistic insights into acetic acid-mediated osmotic adjustment under drought stress remains largely unknown.MethodsHere, we investigated how seed priming and seedling root treatment with acetic acid enabled maize plants overcoming polyethylene glycol (PEG)-induced drought effects.ResultsMaize seeds primed with acetic acid showed better growth performance when compared with unprimed seeds under PEG application. This growth performance was mainly attributed to improved growth traits, such as fresh weight, dry weight, length of shoots and roots, and several leaf spectral indices, including normalized difference vegetation index (NDVI) and chlorophyll absorption in reflectance index (MCARI). The levels of oxidative stress indicators hydrogen peroxide (H2O2) and malondialdehyde (MDA) did not alter significantly among the treatments, but proline content as well as the expression of proline biosynthetic gene, Δ1-PYRROLINE-5-CARBOXYLATE SYNTHETASE 1 (P5CS1) was significantly elevated in plants receiving acetic acid under PEG-treatments. On the other hand, treating the seedlings root with acetic acid led to a significant recovery of maize plants from drought-induced wilting. Although growth traits remained unchanged among the treatments, the enhancement of leaf water content, photosynthetic rate, proline level, expression of P5CS1, and antioxidant enzyme activities along with reduced level of H2O2 and MDA in acetic acid-supplemented drought plants indicated a positive regulatory role of acetic acid in maize tolerance to drought. Moreover, the high expression of P5CS1 and the subsequent elevation of proline level upon acetic acid application were further validated using wild type and proline biosynthetic mutant p5cs1 of Arabidopsis. Results showed that acetic acid application enabled wild type plants to maintain better phenotypic appearance and recovery from drought stress than p5cs1 plants, suggesting a crosstalk between acetic acid and proline metabolism in plants under drought stress.DiscussionOur results highlight the molecular and intrinsic mechanisms of acetic acid conferring plant tolerance to drought stress.

Enhanced Antioxidant Activity and Secondary Metabolite Production in Tartary Buckwheat under Polyethylene Glycol (PEG)-Induced Drought Stress during Germination

“…Another phenolic enzyme, PPO, plays a critical role in oxidizing phenols to quinones, contributing to plant stress tolerance [56,57]. Our results revealed heightened PPO expression levels in response to drought stress, consistent with research indicating the induction of PAL and PPO activities under stress conditions to bolster phenolics and flavonoids, thus reducing oxidative damage [19,37,50]. Furthermore, secondary metabolites, including phenols and flavonoids, were found to be substantially influenced by drought stress and genotype variations, with tolerant cultivars exhibiting higher concentrations.…”

“…•− and MDA concentrations by regulating osmotic solutes and enhancing antioxidant defenses, thereby preserving membrane permeability [49]. Compatible solutes like Pro play pivotal roles in maintaining osmotic potential and scavenging free radicals under drought conditions [37,41,50]. Our study indicated that the dramatic increases in soluble protein and Pro levels in PEG drought-stressed seedlings, with the susceptible genotype (QianKu-4) being more negatively impacted, highlighted its higher susceptibility to osmotic stress.…”

Exploring the Impact of High-Temperature Stress on Physiological, Anatomical, Molecular, Productive, and Quality Parameters in Diverse Olive Cultivars

“…Hence, AFLP markers are exploited in characterizing genetic variability in olive cultivars and accessions (Ercisli et al 2009). Other studies manifested significant associations between DNA markers and morphoagronomic features in specific species (Kar et al 2008;Mesfer ALshamrani et al 2022;Safhi et al 2022;Mahmud et al 2023;Safhi et al 2023). To date, there is no report on the effect of high temperatures in Saudi Arabia on olive oil quality and purity criteria and the association of molecular markers with any of the studied characters.…”

Biochemical, physiological, and molecular responses of diverse olive cultivars to different irrigation regimes

“…Agricultural sectors, especially horticulture, are experiencing increased water demand (Selote and Khanna-Chopra, 2004). Under these conditions, the economic productivity of applied water in agricultural production should be increased (Mahmud et al 2023). Accordingly, olive production in Mediterranean regions that suffer from water scarcity is an ideal choice for cultivation in arid areas, especially newly reclaimed land, due to their high stress tolerance.…”