Himalayan botanical mediated elicitation regulates wheat growth through secondary metabolites and hormonal signalling

Abstract

Plants as a resource of novel elicitors capable of inhibiting pathogen and promoting crop growth are gaining significant attention. Himalayan plants (Colebrookea oppositifolia, Digitalis purpurea and Rumex hastatus), well documented for their pharmacological value and antimicrobial properties were studied for their growth promoting potentials on wheat. Methanolic crude extract obtained from leaf samples of the selected Himalayan plants were applied on wheat through seed priming and foliar spray method. Morphological parameters selected for phyto-stimulatory assessment of treatments were germination percent, shoot length, root length, seedling fresh weight and dry weight, vigour index, stem thickness and root volume, where significant improvements were recorded. Biochemical changes in response to treatment measured were photosynthetic pigments, total phenolic and flavonoid content, osmolytes and antioxidant activity. Wheat plants showed an increment in all the parameters after treatment with botanicals. The growth-promoting potentials of the selected botanicals were further evaluated for quantifying endogenous phytohormone (IAA and GA) levels in wheat through High-Performance Liquid Chromatography (HPLC). Increased expression of hormones was recorded in wheat, which was treatment specific. Wheat stems examined through transverse sections showed increased lignification around the vascular tissue and hypodermis. This study represents the first documented investigation into the growth-promoting effects of selected botanicals on wheat, providing novel insights into their potential as biostimulants. © 2025 Elsevier Ltd