Use of a Biostimulant to Mitigate the Effects of Excess Salinity in Soil and Irrigation Water in Tomato Plants.

Global warming is linked to progressive soil salinisation, which reduces crop yields, especially in irrigated farmland on arid and semiarid regions. Therefore, it is necessary to apply sustainable and effective solutions that contribute to enhanced crop salt tolerance. In the present study, we tested the effects of a commercial biostimulant (BALOX®) containing glycine betaine (GB) and polyphenols on the activation of salinity defense mechanisms in tomato. The evaluation of different biometric parameters and the quantification of biochemical markers related to particular stress responses (osmolytes, cations, anions, oxidative stress indicators, and antioxidant enzymes and compounds) was carried out at two phenological stages (vegetative growth and the beginning of reproductive development) and under different salinity conditions (saline and non-saline soil, and irrigation water), using two formulations (different GB concentrations) and two doses of the biostimulant. Once the experiments were completed, the statistical analysis revealed that both formulations and doses of the biostimulant produced very similar effects. The application of BALOX® improved plant growth and photosynthesis and assisted osmotic adjustment in root and leaf cells. The biostimulant effects are mediated by the control of ion transport, reducing the uptake of toxic Na+ and Cl- ions and favoring the accumulation of beneficial K+ and Ca2+ cations, and a significant increase in leaf sugar and GB contents. BALOX® significantly reduced salt-induced oxidative stress and its harmful effects, as evidenced by a decrease in the concentration of oxidative stress biomarkers, such as malondialdehyde and oxygen peroxide, which was accompanied by the reduction of proline and antioxidant compound contents and the specific activity of antioxidant enzymes with respect to the non-treated plants.

Rhizospheric Microbiome Profiling of Capsicum annuum L. Cultivated in Amended Soils by 16S and Internal Transcribed Spacer 2 rRNA Amplicon Metagenome Sequencing.

Rhizospheric microbiomes of Capsicum annuum L. cultivated either conventionally or amended with a synthetic microbial consortium or a root exudate inductor, were characterized by 16S/internal transcribed spacer 2 (ITS2) rRNA amplicon metagenome sequencing. The most abundant taxa found, although differently represented in each treatment, were Gammaproteobacteria, Alphaproteobacteria, Actinobacteria, and Bacilli, as well as Chytridiomycetes and Mortierellomycotina.

Metagenomes of Soil Samples from an Established Perennial Cropping System of Asparagus Treated with Biostimulants in Southern France.

We report here the metagenomes of soil samples from a perennial cropping system of asparagus that was treated with two biostimulants. Two treatments were compared to an untreated control. Control soil samples were taken at the beginning and at end of the experiment.