Omeprazole treatment elicits contrasting responses to salt stress in two basil genotypes

Abstract

Omeprazole (OP) has been shown to act as a plant growth regulator and enhances tolerance to salt stress. In this study, two Ocimum basilicum genotypes were tested for their responses to OP under salt stress. The two genotypes, Napoletano (NAP) a salt sensitive genotype, and Genovese (GEN) a salt tolerant genotype, had contrasting responses to OP treatment. NAP demonstrated increases in terms of growth (+36%) and salt tolerance (+19%) upon treatment while GEN had a growth increase (+35%) and OP enhanced sensitivity to salt stress (−13%). OP treatment also had an effect on the post-harvest behaviour of these two genotypes by increasing NAP shelf life while decreasing GEN shelf life. The contrasting responses to OP in these two genotypes has provided insight into the role of this molecule in mediating growth and adaptation to stress and, more importantly, into the complexity of the mechanisms mediating these processes.basil, benzimidazole, omeprazole, PPI, proton pump inhibitor, salt stress Abbreviations: DAS, days after sowing; DAST, days after stress treatment; GEN, Genovese; LEA, late embryogenesis abundant; NAP, Napoletano; OP, omeprazole; PPI, proton pump inhibitor; ROS, reactive oxygen species; RWC, relative water content; SDW, shoot dry weight; SFW, shoot fresh weight. † These authors contributed equally to this study.

Omeprazole Promotes Chloride Exclusion and Induces Salt Tolerance in Greenhouse Basil

“…Probably OMP was able to preserve photosynthetic apparatus and transpiration processes because of the higher nitrate and potassium content, and lower chloride concentration present in basil leaves at 80:20, 60:40, and 40:60 NO 3 − :Cl − ratios. Cirillo and co-workers [25], by using OMP to ameliorate salinity toxicity in the salt sensitive basil genotype Napoletano, ascribed the beneficial effect of this small bioactive molecule to the higher acquired capacity to exclude chloride from the cytosol of salt stressed cells. However, OMP more than increasing the ability of plant to better compartmentalize chloride in vacuole or exclude it in the apoplast of basil leaf cells, is able to limit the access of chloride to the above ground parts of the plant, as inferred by the lower Cl − content in the leaf in all the NO 3 − :Cl − treatments with the exception of the 20:80 one.…”

“…Moreover, biologically active small molecules, of natural or synthetic origin, can be supplied exogenously at very low concentrations and relieve or protect plants from saline stress [18][19][20][21]. Several recent studies have highlighted a beneficial role of omeprazole (OMP), a small molecule of 345 Da, in salinity tolerance [22][23][24][25] and mechanical stress tolerance [26]. OMP is a benzimidazole derivative used as a prescribed drug to treat peptic ulcers, gastroesophageal reflux, and other hypersecretory states in humans for its ability in inhibiting the P-type IIC proton pump H + /K + -ATPases in the gastric parietal cell, blocking the final step in the gastric acid secretory pathway [27][28][29].…”

“…Moreover, OMP is able to increase root growth and nutrients resource efficiency in control plants [3] and mechanical stressed plants [26]. The involvement of OMP in the regulation of plant radical growth and protection from salt stress certainly entails a complex signaling and/or hormonal action [3,23], determined at the genetic level, as demonstrated by the recent work of Cirillo et al [25] on two basil contrasting genotypes, that, though, has not yet been unraveled. Cirillo et al [25] attributed the OMP beneficial effect on the salt sensitive basil genotype Napoletano to this small molecule specific capacity to improve chloride exclusion from the cytosol of salt stressed plants.…”

“…The involvement of OMP in the regulation of plant radical growth and protection from salt stress certainly entails a complex signaling and/or hormonal action [3,23], determined at the genetic level, as demonstrated by the recent work of Cirillo et al [25] on two basil contrasting genotypes, that, though, has not yet been unraveled. Cirillo et al [25] attributed the OMP beneficial effect on the salt sensitive basil genotype Napoletano to this small molecule specific capacity to improve chloride exclusion from the cytosol of salt stressed plants. However, their study, as well as the most of the studies performed on the effects of salinity on plants, have used NaCl as salt, and focused on sodium accumulation and toxicity, considering sodium as the main problem responsible for the reduction of plant growth, development, and survival [5,[30][31][32][33][34][35].…”

Physiological Basis of Salt Stress Tolerance in a Landrace and a Commercial Variety of Sweet Pepper (Capsicum annuum L.)

“…At the end of the experiment (DAT 168), stems and leaves of the three plants per treatment were separately sampled for the quantification of Na + and Cl − content by means of ion chromatography using a Dionex ICS-3000 (Sunnyvale, CA, USA) [ 48 ] on three replicate plants.…”