Evaluating the Endophytic Activities of Beauveria bassiana on the Physiology, Growth, and Antioxidant Activities of Extracts of Lettuce (Lactuca sativa L.)

Abstract

Endophytic entomopathogens have growth promoting, nutrient fortifying, and anti-insect properties that could improve the yield and quality of lettuce (Lactuca sativa L.). Lactuca sativa is a vegetable crop with high demand; however, it is susceptible to aphid infestations. This study’s objectives were to assess the pathogenicity of Beauveria bassiana (strain: SM3) (Bals.) Vuil. (Hypocreales) against Myzus persicae Sulzer, tissue colonization of lettuce by conidia of B. bassiana, as well as the effects of fungal inoculation on growth, tissue nutrient content, and proximate composition of the lettuce plants. Furthermore, the involvement of tissue nutrients in mediating the influence of endophytic fungus on the plant traits was examined. Insects and plants were exposed to four fungal conidial concentrations: 0, 1 × 106, 1 × 107 and 1 × 108 conidia mL−1 in an anti-insect bioassay and a greenhouse experiment, respectively. The B. bassiana strain was pathogenic against M. persicae, inducing mean insect mortality of 78% at the highest concentration (1 × 108 conidia mL−1). The B. bassiana endophytically colonized up to 76% of plants exposed to 1 × 108 conidia mL−1. Crown size and plant height varied significantly among treatments. However, the plant fresh and dry weights and nutrient elements N, P, K, Ca, and Mg did not vary significantly among treatments. Among the plant macronutrients assessed, only tissue carbon content was significantly (p < 0.01) affected by conidial treatments. The tissue C and Cu contents significantly correlated with the antioxidant capacity of the lettuce plants. Most of the micronutrients, viz. Mn, Fe, Cu, and B were remarkably higher (p < 0.05) in the fungus-treated plants than in the control plants. The antioxidant capacity (FRAP and TEAC) of plant extracts varied significantly (p < 0.001) among treatments, with the highest conidial treatment yielding the most increased antioxidant activity. In conclusion, the B. bassiana strain was endophytic to lettuce, pathogenic against M. persicae, and induced increased micro-nutrient tissue contents and antioxidant activities. This study demonstrated that B. bassiana could be potentially used in the biofortification of nutritive and medicinal qualities of plants.

Seed priming with endophytes on physiological, biochemical and antioxidant activity of hybrid maize (Zea mays l.) COH (M) 8 seeds

“…Similarly, seed priming with M. anisopliae @ 5% (T 3 ) and B. subtilus @ 8% (T 4 ) recorded more root length of 23.7 cm and 23.4 cm, respectively, which were 15.04% and 13.59% over control. Endophytic fungi, enhance seedling growth by increasing nutrient assimilation and production of plant growth promoters such as gibberellin, indoles acetic acid (IAA), cytokinins and production of siderophores (Macuphe et al, 2021). Seed priming with three different endophytes had increased dry matter production (DMP) to the range from 13.59% to 15.22% over non-primed seeds.…”

Vitamin contents and antioxidant capacity of hydroponic grown sweet basil inoculated with endophytic bacteria

“…The variability of nutrients in endophyte inoculated crops is generally dependent on plant species, the endophyte strain, the endophyte concentration, the inoculation method, and growth conditions (Mangmang et al, 2015;Naqqash et al, 2016;Pii et al, 2018). At a concentration of 1 × 10 6 conidia/mL for example, Beauveria bassiana significantly decreased protein contents in lettuce leaves while 10-and 100-times higher concentrations did not affect protein contents (Macuphe et al, 2021). The data may not directly be extrapolated as Beauveria bassiana is a fungal strain and the vegetables are different.…”

“…Other bacterial endophytes belonging to Agrobacterium, Pseudomonas, Enterobacter, and Rhizobium species increased the growth and production of indole-3-acetic acid in potato plants (Naqqash et al, 2016). In lettuce, the fungus Beauveria bassiana had an endophytic role by promoting resistance to pathogens and by inducing an increase in micronutrient (zinc, iron, manganese) tissue contents (Macuphe et al, 2021) while Piriformospora indica enhanced by 7.6-fold the concentration of zinc (Padash et al, 2016). In a previous work, we reported the promotion of root and shoot growth of aquaponically grown basil, lettuce, and bok choy plants due to inoculation with bacteria endophytes (Mayer et al, 2019).…”

Evaluation of Native Entomopathogenic Fungi for the Control of Fall Armyworm (Spodoptera frugiperda) in Thailand: A Sustainable Way for Eco-Friendly Agriculture

“…Although our study was laboratory-based, we investigated some records on the endophytic influence that may be caused by B. bassiana on plants, and it is clear that it is friendly and does not cause any significant changes in the plant fresh and dry weight as well as the nutrient elements [56]. In fact, the endophytic strains have been reported to promote plant growth and at the same time help in controlling insect pests [57,58].…”