Ikuyinminu et al., (2022) Agronomy12 (4) 809
Enhancing Irrigation Salinity Stress Tolerance and Increasing Yield in Tomato Using a Precision Engineered Protein Hydrolysate and Ascophyllum nodosum-Derived Biostimulant
https://www.mdpi.com/2073-4395/12/4/809
Summary
Salinity affects approximately 20% of the world’s landmass, impacting one-third of agricultural areas, and hindering global food production. This stress reduces plant growth by impeding water uptake and causing the harmful accumulation of ions like sodium and chloride in crops. As a result, it leads to limited water uptake, inhibited tissue growth, nutrient imbalances, diminished crop quality and yield loss.
In arid regions with high evaporation rates, poor-quality irrigation water accumulates salt in the soil, leading to salinity stress in crops. To tackle this issue, sustainable solutions like biostimulants are emerging. Blocsal, developed by Brandon Bioscience, is a novel biostimulant featuring the PSI®475 molecular signature, derived from protein hydrolysate and Ascophyllum nodosum extract.
Our team of scientists conducted a study to assess the effects of Blocsal on tomato plants subjected to salinity stress. In this investigation, they analysed an array of markers, encompassing phenotypic observations, physiological assessments, biochemical analyses, and transcriptome profiling.
The chemical and structural composition of Blocsal was determined and was found to have varying rates of seaweed carbohydrates (total uronics, fucose, laminarin, and free mannitol), polyphenols, total free amino acids, and soluble peptides.
Using high-throughput root microphenotyping in Arabidopsis thaliana, we tested Blocsal’s efficacy in mitigating salinity stress in a laboratory setting through root application. High levels of salinity typically reduce root growth, but with Blocsal application, under stress conditions, primary root length was increased, highlighting its potential to enhance root growth in the face of salinity stress.
To access the effects Blocsal had on a relevant agricultural crop, an experimental design was formulated using tomato. Blocsal was applied to crops, vis foliar application. 3 days after application, salinity stress was initiated. Initially, 50mM NaCl (EC:5.8dS m-1) was applied for 7 days. Thereafter, 100 mM NaCl (EC:10.7dS m-1) was applied for 21 days. After a total of 28 days, plants were watered with tap water (EC: 0.7dS m-1). Blocsal was applied again during the recovery period. Plants were watered for another 67 days and harvested at day 154.
Salinity stress adversely impacted plant height, primary root length, and root biomass. However, when treated with Blocsal, the primary root length increased by 5.5% compared to stressed controls. Salinity stress reduced fruit yield, but Blocsal not only restored it but also led to an increase. Additionally, sugar content (Brix) decreased under stress, but Blocsal boosted it by an average of 9.9% over both stressed and unstressed crops.
The application of Blocsal increased relative water content (RWC) in stressed crops, enhancing water retention. This was achieved by triggering the production of osmolytes, like proline (accumulating by 42%) and soluble sugars (e.g., glucose, sucrose, fructose) which a plant produces in defence against osmotic stress.
Blocsal significantly influences ion balance. It reduces leaf Na+ levels by 20% compared to untreated plants and counters the 15% decrease in leaf K+ caused by salinity stress, with a 12% accumulation. Saline stress persists even after tap water rewatering, resulting in elevated leaf Na+ levels in stressed crops. The ideal K+/Na+ ratio improves by 32.3% in stressed plants treated with Blocsal.
Our scientist further evaluated the mode of action of Blocsal by analysing transcriptome data, studying genetic changes in tomato leaves during salinity stress and Blocsal application. Key salinity stress tolerance genes, namely SOS1, HKT1, and NHK1, were found to be upregulated, exhibiting increased expression after Blocsal application. These genes play a crucial role in regulating ion balance, preventing sodium buildup, and inducing tolerance mechanisms in crops exposed to salinity.
In summary, BLOCSAL has a positive impact on a crop’s ability to initiate salinity tolerance mechanisms. This, in turn, safeguards against yield loss, preserves quality markers, and suggests its potential to protect growers’ profits in salinity-stressed areas.
If you would like to know more about our research and our range of biostimulants, speak to us directly
