Bioformulations with Beneficial Microbial Consortia, a Bioactive Compound and Plant Biopolymers Modulate Sweet Basil Productivity, Photosynthetic Activity and Metabolites

• Main Authors: Ernesto Comite, Christophe El-Nakhel, Youssef Rouphael, Valeria Ventorino, Olimpia Pepe, Assunta Borzacchiello, Francesco Vinale, Daniela Rigano, Alessia Staropoli, Matteo Lorito, Sheridan L. Woo
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Pathogens
• Subjects: 6-pentyl-α-pyrone; rosmarinic acid; <i>Ocimum basilicum</i> L.; <i>Trichoderma</i>; <i>Azotobacter</i>
• Online Access: https://www.mdpi.com/2076-0817/10/7/870

Increasing attention is being given to the development of innovative formulations to substitute the use of synthetic chemicals to improve agricultural production and resource use efficiency. Alternatives can include biological products containing beneficial microorganisms and bioactive metabolites able to inhibit plant pathogens, induce systemic resistance and promote plant growth. The efficacy of such bioformulations can be increased by the addition of polymers as adjuvants or carriers. <i>Trichoderma afroharzianum</i> T22, <i>Azotobacter chroococcum</i> 76A and 6-pentyl-α-pyrone (6PP; a <i>Trichoderma</i> secondary metabolite) were administrated singularly or in a consortium, with or without a carboxymethyl cellulose-based biopolymer (BP), and tested on sweet basil (<i>Ocimum basilicum</i> L.) grown in a protected greenhouse. The effect of the treatments on basil yield, photosynthetic activity and secondary metabolites production was assessed. Photosynthetic efficiency was augmented by the applications of the bioformulations. The applications to the rhizosphere with BP + 6PP and BP + T22 + 76A increased the total fresh weight of basil by 26.3% and 23.6%, respectively. Untargeted LC-MS qTOF analysis demonstrated that the plant metabolome was significantly modified by the treatments. Quantification of the profiles for the major phenolic acids indicated that the treatment with the T22 + 76A consortium increased rosmarinic acid content by 110%. The use of innovative bioformulations containing microbes, their metabolites and a biopolymer was found to modulate the cultivation of fresh basil by improving yield and quality, thus providing the opportunity to develop farming systems with minimal impact on the environmental footprint from the agricultural production process.