With the increasing demand for sustainable agriculture, rhamnolipids (RHAs), a class of biosurfactants, have emerged as promising eco-friendly biostimulants. However, their full potential has been limited by impurities and uncertain mechanisms. This study investigated the effects of high-purity RHAs on wheat (Triticum aestivum) growth and yield through controlled laboratory experiments and multiyear field trials. In laboratory assays, optimal RHA concentrations (5-10 mg·L-1) promoted seedling growth by enhancing chlorophyll content, root-shoot development, and tillering. Transcriptomic profiling revealed that RHA treatment upregulated genes involved in gibberellic acid (GA3) and zeatin (ZT) biosynthesis, nitrogen uptake, and photosynthesis. In the field, low doses of RHA application (∼45 g·ha-1) significantly enhanced tillering capacity and promoted earlier flowering while delaying senescence. Importantly, these physiological enhancements translated into significant yield increases of 11.9 and 14.8% across 2 consecutive years. The study provides novel mechanistic insights into RHA-mediated growth promotion, highlighting RHAs as a promising, eco-friendly biostimulant for sustainable wheat production.
Shen et al. (Mon,) studied this question.