Exogenous application of glutamic acid promotes cucumber (Cucumis sativus L.) growth under salt stress conditions

Abstract

Salinity is expected to be the major destructive abiotic stress that causes ionic and oxidative damage leading to growth reduction and ultimately plant death. Glutamic acid (GA) is an α-amino acid that is used by almost all living beings in the biosynthsis of proteins. Therefore, in the present study, we tried to investigate the effect of foliar application of glutamic acid (GA) on cucumber (Cucumis sativus L.) under altered salinity levels. Cucumber seedlings were grown in plastic pots under greenhouse conditions by applying four levels of salinity (0, 3 dS/m, 6 dS/m and 12 dS/m) and two levels of foliar applied GA (0, 10 mM). Salinity was induced by mixing the salt and soil before seed sowing; however, exogenous GA was applied when the vine length was reached up to maximum height. Morphological characters showed disruptive response under saline conditions especially in indigenous cultivar (local cucumber represented as V1). Enhanced activities of superoxide dismutase (0.29 u g-1 FW), guaiacol peroxidase (3.51 u g-1 FW) and ascorbate peroxidase (0.39 µmol AsA.mg-1 Chl min-1) were observed in salt-stressed cucumber leaves. Both varieties showed unusual behavior for malondialdehyde in decreasing manner with increasing salinity levels (2.0333 µmol g-1 FW at 12dS/m in local cultivar; while, 1.98 µmol g-1 FW at 12dS/m in hybrid cultivar SSC-228). However, exogenously applied GA played a beneficial role in promoting all morphological parameters under stress with increasing scavenging abilities against reactive oxygen species. Foliar application of GA improved plant defense mechanism with minimum destruction. Remarked calculations showed that under salt stress, GA improved plant stress tolerance against salinity by maximizing the growth rate.

Unrevealing the impact of pulsed electric fields (PEF) on cucumber seed vigour and surface disinfection

“…Changes in EC by the PEF treatments and time are correlated with the changes in both membrane fluidity and membrane permeability in the cucumber seeds (3,6,48). Both percentage and rate of germination were reduced by the increased salinity level (1,31,37). Salt tolerance in some crops was linked with antioxidant systems (AOS) (12) as it acted as the control mechanisms to reactive oxygen species (ROS) (5) lethally damaging the cell membrane in plants (62).…”

Using Some Organic Substances to Alleviate Deleterious Impacts of Soil Salinity on Fennel Plant

“…It has shown incredible effectiveness in enhancing various morphological characteristics, even in the face of stress, by increasing its ability to neutralize harmful reactive oxygen species. In addition, GA has been found to strengthen plant defense mechanisms while minimizing damage, ultimately leading to improved tolerance to salinity by maximizing plant growth (Iqbal et al, 2021). Applying glutamic acid exogenously enhanced CAT proteins' production, photosynthetic efficiency, and antioxidant enzymes activity, additionally, there was a modification in the way genes coding for various antioxidant enzymes (specifically APXs, SODs, and CATs) were expressed (Lee et al, 2021).…”

Silicon-mediated improvement of biomass yield and physio-biochemical attributes in heat-stressed spinach (

“…In tomato, high stomatal conductivity and transpiration rate under heat stress improve leaf cooling, providing better protection for chlorophyll and maintaining relatively high photosynthetic rate (Haque et al 2021). Under abiotic stress environments, photosynthetic pigment degradation occurs; for example, under salt stress conditions, chlorophyll pigments break down (Iqbal et al 2021). The improvement of spinach physiological attributes might be the result of increased total chlorophyll content with optimum Si application under heat-stressed conditions (Fig.…”