A dual-omics approach for profiling plant responses to biostimulant applications under controlled and field conditions

A comprehensive approach using phenomics and global transcriptomics for dissecting plant response to biostimulant is presented using tomato plants (Solanum lycopersicum cv. Micro-Tom and Rio Grande) cultivated in laboratory, greenhouse, and open field conditions. Biostimulant treatment based on an Ascophyllum nodosum extract (ANE) was applied as foliar spray with two doses (1 or 2 l ha-1) at three different phenological stages (BBCH51, BBCH61, and BBCH65) during flowering phase. Both ANE doses resulted in greater net photosynthesis rate, stomatal conductance and fruit yield across all culture conditions. A global transcriptomic analysis of leaves from plants grown in climatic chamber revealed a greater number of differentially expressed genes (DEGs) with the low ANE dose compared to the greater one. The first application at the onset of flowering triggered a moderate transcriptome change, while the second and third applications induced a broader one suggesting a cumulative effect of the treatment. The functional enrichment analysis of DEGs highlighted pathways related to stimulus response and photosynthesis, consistent with the morpho-physiological observations. This study is the first comprehensive dual-omics approach for profiling plant responses to biostimulant across three different culture conditions.