Combined Biostimulant Applications of Trichoderma spp. with Fatty Acid Mixtures Improve Biocontrol Activity, Horticultural Crop Yield and Nutritional Quality

Abstract

The growing demand for safer foods reflects the public perception of the adverse consequences of chemicals used in agriculture. This research aimed at developing new biological formulations based on the combination of small microbial consortia containing two Trichoderma spp., with a medium–long chain fatty acids mixture (FAm). The bioactivity of these formulations was investigated on different vegetable crops in terms of biocontrol, growth promotion, yield and quality improvements. FAm application reduced Botrytis cinerea necrosis by up to 90% compared to the infected control plants and some of the assayed Trichoderma spp. + FAm combinations contained Rhizoctonia disease, reaching more than 90% reduction of tomato and lettuce plant mortality. An increasing yield, ranging to 25 and 90%, was recorded on treated tomato, lettuce and kohlrabi compared to untreated plants. A significant enrichment in carotenoids (+60%) and glucosinolates (+39%) was measured on biotreated plants compared to controls. Untargeted LC-MS analysis revealed a higher content of tomatine and dehydro-phytosphingosine, glycoalkaloids involved in defense responses, in Trichoderma spp. + FAm combination-treated plants. The combined biostimulant applications of Trichoderma spp. with FAm were able to improve the performances of different horticultural plant species, producing a premium quality marketable vegetable with higher antioxidant content.

Biodegradable Mulch Films and Bioformulations Based on Trichoderma sp. and Seaweed Extract Differentially Affect the Metabolome of Industrial Tomato Plants

“…Regarding tomatidine, significant increases in tomato berries were associated with the application of T22, both alone and in combination with Phylgreen ® . A similar result was observed in tomatoes treated with different strains of Trichoderma, either alone or in combination with other microorganisms, as reported by Lanzuise et al [38]. Like all glycoalkaloids, both α-tomatine and tomatidine have antifungal properties that play a role in plant defence mechanisms against insects and phytopathogenic bacteria [39].…”

“…Like all glycoalkaloids, both α-tomatine and tomatidine have antifungal properties that play a role in plant defence mechanisms against insects and phytopathogenic bacteria [39]. These compounds exert their protective effects by targeting membrane sterols in pests and pathogens [38]. Hence, an increase in these compounds is certainly one of the advantages of applying treatments based on microbial biostimulants.…”

Water Stress Alleviation Effects of Biostimulants on Greenhouse-Grown Tomato Fruit

“…Such compounds could include polyphenols, as it is well known that their biosynthesis is induced under stress and they may exert antimicrobial activity [81][82][83], although this activity is associated with the phenolic skeleton and the position of the phenyl group [84]. On the other hand, other researchers suggest fatty acids as the compounds responsible for the antibacterial effects [85], although Ronga et al [86] associated the antibacterial effects with the differences in cell wall structures between Gram-positive and Gram-negative bacteria. Moreover, oligosaccharides obtained from seaweed extracts could induce the biosynthesis of phenylpropanoids with antibacterial effects [87], while the aqueous extracts obtained from Baltic seaweeds after boiling also exerted antimicrobial effects due to the high content of phenolic compounds [88].…”

A Simple Formula of the Endophytic Trichoderma viride, a Case Study for the Management of Rhizoctonia solani on the Common Bean

“…The bioactive constituents of the T. viride acetonic extract detected by GC-MS were palmitic acid, oleic acid, and octadecenoic acid, while hexadecanoic acid was reported as the main active component of T. harzianum [ 39 ]. Several studies have reported the antibacterial and antifungal activity of free fatty acids from various organisms [ 40 , 41 , 42 ]. In this respect, Lanzuise et al [ 42 ] reported a strong antifungal behavior of long-chain (C14-C20) fatty acids of vegetable origin plus T. harzianum, and T. virens .…”

“…Several studies have reported the antibacterial and antifungal activity of free fatty acids from various organisms [ 40 , 41 , 42 ]. In this respect, Lanzuise et al [ 42 ] reported a strong antifungal behavior of long-chain (C14-C20) fatty acids of vegetable origin plus T. harzianum, and T. virens . Palmitic acid and acetic acid were reported as the main bioactive constituents of T. viride and T. harzianum , which have high antimicrobial activity against the growth of F. verticillioides and F. proliferat um [ 39 ].…”