Work

Karrikin1 mitigates salt stress in creeping bentgrass (Agrostis stolonifera) via physiological regulation and metabolite reprogramming

Year: 2025

Type: article

Abstract: Salinity poses a globally prevalent environmental stressor impairing plant growth and production. Karrikins (KARs), a recently identified class of plant growth regulators, are butenolide compounds generated during plant materials combustion, and can promote seed germination and subsequent seedling establishment under various abiotic stresses. However, the role of KARs in mediating physiological and metabolic processes under salinity remains poorly understood. This study therefore aimed to elucidate the effects of KAR 1 on ionic homeostasis, redox regulation, and metabolic reprogramming in salt-stressed creeping bentgrass ( Agrostis stolonifera ). Creeping bentgrass plants received foliar applications of either 100 nM KAR 1 or distilled water and then were exposed to non-stress or 200 mM salt stress for a 21-day experimental period. Foliar KAR 1 application mitigated salt stress-induced negative effects by significantly increasing shoot biomass, leaf relative water content, total chlorophyll and chlorophyll a content, proline accumulation, and antioxidant enzyme activities, while concurrently diminishing electrolyte leakage and decreasing malondialdehyde and hydrogen peroxide content. Moreover, KAR 1 elevated K + and Mg 2+ content in creeping bentgrass leaves and decreased Na + /K + ratio under salt stress. Metabolomic analysis revealed that enhanced salt tolerance by KAR 1 application could be associated with metabolic reprogramming of specific amino acids for osmotic adjustment, and metabolites involved in alpha-linolenic acid and phenylpropanoid biosynthesis pathways for membrane integrity and stabilization. ● KAR 1 application enhanced salt tolerance of creeping bentgrass ● KAR 1 enhanced APX and SOD activities under salt stress, and alleviated ROS damage ● KAR 1 increased K + and Mg 2+ content and maintained high K + /Na + under salt stress ● Accumulation of amino acids by KAR 1 contributed to osmotic adjustment under stress ● KAR 1 modulated ‘phenylpropanoid biosynthesis’ and ‘α-linolenic acid metabolism’

Source: Plant Physiology and Biochemistry

DOI: 10.1016/j.plaphy.2025.110800