Penicillium glabrum acted as a heat stress relieving endophyte in soybean and sunflower

Abstract

High temperature is one of the compelling ecological stresses faced by the plants owing to anthropogenic activities of mankind. Recently, endophytic fungi are considered to be a novel tool to counteract the consequences of thermal stress in crops. Owing to the problem, we isolated fungal endophytes from Dryopteris blanfordii and their growth favoring potential in rice seedlings. Endophytic fungi have the proficiency to secrete plant growth stimulating secondary metabolites that help the host plants to restore growth under harsh environments. The isolated Penicillium glabrum (DryR30) helped the host plant species, i.e. Glycine max L. and Helianthus annuus L. under thermal stress. P. glabrum associated with G. max and H. annuus exposed to 40ºC not only boosted their host growth attributes (total biomass, plant height and chlorophyll contents), but also significantly curtailed the synthesis of reactive oxygen species and lipids peroxidation. Moreover, the abscisic acid (ABA) and proline concentrations were significantly reduced, while the accumulation of ROS-degrading enzymes, such as catalase (CAT), peroxidase (POD), ascorbic acid oxidase (AAO), glutathione reductase (GR) and superoxide dismutase (SOD) were increased in P. glabrum-associated crops. Additionally, the protein, lipid and sugar contents in tested plants were also improved. These stirring findings suggest that P. glabrum can be applied to food crops as a thermal stress alleviation tool.