Plant Biostimulants Based on Selenium Nanoparticles Biosynthesized by Trichoderma Strains

Abstract

Biostimulants are a novel class of additives used to promote plant vigor and resistance to abiotic stress, such as desiccation. The most used biostimulants are humic and fulvic acids, seaweed extracts, and biopolymers, as well as beneficial bacterial and fungal strains [1]. One such beneficial fungal strain is Trichoderma, which exists in the soil and colonizes the root system and can enhance root proliferation [2]. Trichoderma spp. were shown to be able to bio-synthesize selenium nanoparticles (SeNPs) [3]. Selenium (Se) is known to have beneficial effects on plant and animal metabolism at low concentrations, being involved in protection against reactive oxygen species (ROS) in the form of selenoproteins [4]. Se can also act as a protective agent against the harmful effects of heavy metals [5]. Nevertheless, Se has a narrow physiological window, and the toxicity depends on Se species, SeNPs being much less toxic than Se salts [4].The aim of this study was to develop and test a plant biostimulant based on SeNPs bio-synthesized by Trichoderma spp. by monitoring its effects on different stages of plant growth, as well as some biochemical markers of these effects. The tests were conducted on Vigna radiata seeds, which were germinated in aqueous solutions of SeNPs or Se selenite and compared to a control group that were germinated in water. The germinated seeds were planted in sterilized soil and grown in a lux-chamber. Post-harvest, the plant material was ground into a powder after freezing with liquid nitrogen, and small samples of this powder were used to assess lipid peroxidation and chlorophyll production of the plant tissue. SeNPs were found to be much less toxic than Se selenite and to protect the plants against phytopathogens.

Selenium biofortification in the 21st century: status and challenges for healthy human nutrition

“…Harnessing SeNPs as Se-nanofertilizers holds the potential for synchronized Se management in terms of release and uptake by crops, while preventing Se losses in agroecosystems that may occur when commercial Se fertilizers containing selenate and selenite salts are employed (Babajani et al 2019). SeNPs seem to be less toxic to plants than selenate and selenite salts, as reported in tobacco (Nicotiana tabacum L.) (Domokos-Szabolcsy et al 2012), garlic (Allium sativum L.) (Li et al 2020) and Vigna radiata plants (Bărbieru et al 2019). They can also improve the quality traits of vegetables, as described in strawberry (Fragaria × ananassa) and tomato (Solanum Lycopersicon L.), whose fruits were more enriched in organic acids (e.g., malic, citric and succinic acids) and sugars (e.g.…”

Humic Substances as Microalgal Biostimulants—Implications for Microalgal Biotechnology

“…Organic plant biostimulants are seaweed and botanical extracts [ 106 , 107 , 108 , 109 ], humic and fulvic acids [ 110 , 111 ], protein hydrolysates [ 112 , 113 ], chitosan [ 114 , 115 ], and other biopolymers [ 116 , 117 , 118 ]. Inorganic plant biostimulants are plant-beneficial elements, such as silicon [ 119 , 120 ] or selenium [ 121 , 122 ], which determine PB-specific biological effects when applied to cultivated plants.…”

Endophytic Nanotechnology: An Approach to Study Scope and Potential Applications

“…Several studies have reported on the biostimulant properties of different NPs (Byczyńska, 2017;Juárez-Maldonado et al, 2019;Kumaraswamy et al, 2019). Van et al (2013) (Keswani et al, 2014;Keswani et al, 2016;Bȃrbieru et al, 2019). Venkatachalam et al (2017) studied the plant growth-promoting role of phycomolecules coated ZnO-NPs with phosphorus (P) supplementation in cotton and observed that the combination of bioengineered ZnO-NPs with P supplementation resulted into an increase in biomass, photosynthetic pigments, total soluble proteins, and antioxidant enzyme activities.…”