Transcriptome Analyses and Antioxidant Activity Profiling Reveal the Role of a Lignin-Derived Biostimulant Seed Treatment in Enhancing Heat Stress Tolerance in Soybean

Abstract

Soybean (Glycine max Merr.) is a worldwide important legume crop, whose growth and yield are negatively affected by heat stress at germination time. Here, we tested the role of a biostimulant based on lignin derivatives, plant-derived amino acids, and molybdenum in enhancing soybean heat stress tolerance when applied on seeds. After treatment with the biostimulant at 35 °C, the seed biometric parameters were positively influenced after 24 h, meanwhile, germination percentage was increased after 72 h (+10%). RNA-Seq analyses revealed a modulation of 879 genes (51 upregulated and 828 downregulated) in biostimulant-treated seeds as compared with the control, at 24 h after incubation at 35 °C. Surprisingly, more than 33% of upregulated genes encoded for ribosomal RNA (rRNA) methyltransferases and proteins involved in the ribosome assembly, acting in a specific protein network. Conversely, the downregulated genes were involved in stress response, hormone signaling, and primary metabolism. Finally, from a biochemical point of view, the dramatic H2O2 reduction 40%) correlated to a strong increase in non-protein thiols (+150%), suggested a lower oxidative stress level in biostimulant-treated seeds, at 24 h after incubation at 35 °C. Our results provide insights on the biostimulant mechanism of action and on its application for seed treatments to improve heat stress tolerance during germination.

The application of a biostimulant based on tannins affects root architecture and improves tolerance to salinity in tomato plants

“…With regard to glutathione (GST), this enzyme catalyzes the conjugation between reduced glutathione (GSH) and electrophilic substrates. In particular, these enzymes have been largely studied for their capacity to bind toxic exogenous compounds, thus protecting plants from multiple types of stresses 61 , 62 , including abiotic stress responses 62 , 63 , and their upregulation may suggest a protective antioxidant effect of VIVEMA TWIN application.…”

“…The primers of both reference and selected target genes, were designed using Primer3 software 80 and are reported in Supplementary Table 2 . The relative gene expression levels were calculated by using the Pfaffl method 62 , 81 , meanwhile the variations in gene expression were calculated as relative quantification of the target genes in relation to the reference gene, Elongation Factor 1 as shown before 24 , 62 .…”

“…Three µg of total RNA was used as input material for the generation of the sequence libraries. Transcriptome assembly, coding potential analysis, expression analysis, GO enrichment and KEGG pathway analysis, were done using Novogene standardized protocols as already shown before in other similar studies 62,[75][76][77] . Raw counts produced by HTSeq-count were normalized based on the DESeq2 normalization method 78 .…”

The Application of a Plant Biostimulant Based on Seaweed and Yeast Extract Improved Tomato Fruit Development and Quality

“…Despite both the differences in the raw materials employed and the large variety of phytochemicals present in the various biostimulant formulations [ 17 ], their application in very small amounts seems to be enough to promote plant growth. In particular, scientific evidence shows that treatment with biostimulants can affect plant growth processes by enhancing water and/or nutrient uptake [ 18 ], root and shoot growth [ 12 , 14 , 19 ], activity of key enzymes involved in primary or secondary metabolism [ 17 , 20 ], and plant antioxidant defense system [ 21 ]. Moreover, treatments with biostimulants seem to be able to positively affect fruit quality in terms of nutritional values and nutraceutical properties [ 13 , 14 , 15 , 16 ].…”

A Beginner’s Guide to Osmoprotection by Biostimulants

“…Stress-tolerant or sensitive varieties can be compared using metabolomic tools to detect and evaluate the differences arising from the interactive coevolution of plants with their environments [ 214 ]. In this way, the search continues for new compounds to further the advance into various fields of biostimulation [ 215 ].…”