Association of jasmonic acid priming with multiple defense mechanisms in wheat plants under high salt stress

Abstract

Salinity is a global conundrum that negatively affects various biometrics of agricultural crops. Jasmonic acid (JA) is a phytohormone that reinforces multilayered defense strategies against abiotic stress, including salinity. This study investigated the effect of JA (60 μM) on two wheat cultivars, namely ZM9 and YM25, exposed to NaCl (14.50 dSm−1) during two consecutive growing seasons. Morphologically, plants primed with JA enhanced the vegetative growth and yield components. The improvement of growth by JA priming is associated with increased photosynthetic pigments, stomatal conductance, intercellular CO2, maximal photosystem II efficiency, and transpiration rate of the stressed plants. Furthermore, wheat cultivars primed with JA showed a reduction in the swelling of the chloroplast, recovery of the disintegrated thylakoids grana, and increased plastoglobuli numbers compared to saline-treated plants. JA prevented dehydration of leaves by increasing relative water content and water use efficiency via reducing water and osmotic potential using proline as an osmoticum. There was a reduction in sodium (Na+) and increased potassium (K+) contents, indicating a significant role of JA priming in ionic homeostasis, which was associated with induction of the transporters, viz., SOS1, NHX2, and HVP1. Exogenously applied JA mitigated the inhibitory effect of salt stress in plants by increasing the endogenous levels of cytokinins and indole acetic acid, and reducing the abscisic acid (ABA) contents. In addition, the oxidative stress caused by increasing hydrogen peroxide in salt-stressed plants was restrained by JA, which was associated with increased α-tocopherol, phenolics, and flavonoids levels and triggered the activities of superoxide dismutase and ascorbate peroxidase activity. This increase in phenolics and flavonoids could be explained by the induction of phenylalanine ammonia-lyase activity. The results suggest that JA plays a key role at the morphological, biochemical, and genetic levels of stressed and non-stressed wheat plants which is reflected in yield attributes. Hierarchical cluster analysis and principal component analyses showed that salt sensitivity was associated with the increments of Na+, hydrogen peroxide, and ABA contents. The regulatory role of JA under salinity stress was interlinked with increased JA level which consequentially improved ion transporting, osmoregulation, and antioxidant defense.

Secondary metabolites, hormonal homeostasis, and antioxidant enzymes of Moringa oleifera in response to white or violet Light Emitting Diodes (LEDs) combined with cytokinins under tissue culture conditions

“…Because anthocyanins are powerful antioxidants, flavonoids, in general, may be able to remove reactive oxygen species (ROS) produced during photosynthesis, especially in the presence of photoinhibition (typically high light and low temperature). In addition, although anthocyanins are often contained in vacuoles, colorless cytosolic anthocyanins may function to remove ROS produced by mitochondria and chloroplasts (Neill and Gould, 2003;Sheteiwy et al, 2022).…”

The Interaction of Fungicide and Nitrogen for Aboveground Biomass from Flag Leaf Emergence and Grain Yield Generation under Tan Spot Infection in Wheat

“…Furthermore, under drought stress, hexaploid species had higher grain yield, grains per spike, grain weight, aboveground biomass, harvest index, and water use efficiency than tetraploid species [ 3 , 4 ]. Genes inducing thermotolerance in plants have also been discovered [ 5 ], and the role of jasmonic acid in the morphological, biochemical, and genetic levels of salt-stressed and non-salt-stressed wheat plants, as reflected in their yield attributes, has been clarified [ 6 ]. Furthermore, while the roots’ functional traits determine the efficiency of pre-anthesis N uptake, the efficiency of using the N taken up before anthesis to produce grains can be influenced by a variety of factors, including the presence of arbuscular mycorrhiza (AMF) and pathogens [ 7 ].…”

Temporal complementarity between roots and mycorrhizal fungi drives wheat nitrogen use efficiency

“…Wheat is one of the major food crops, which is of exceptional importance in feeding an increasing human population around the globe (Lehnert et al ., 2017; S. J. Zhang et al ., 2019; Sheteiwy et al ., 2022). However, high nitrogen (N) fertiliser input in combination with low use efficiency results in severe environmental issues and high economic burden for wheat farmers (Masclaux‐Daubresse et al ., 2008).…”