Growth Promotion in Arabidopsis thaliana Induced by Fungal Endophytes Isolated from Plants Growing in Extreme Habitats.

Plants and microbes have co-evolved in nature over the past few years for their better adaptation. This intricate symbiotic relationship is captured in the hologenome concept, which emphasizes that the combined genome of plants and their associated microbial partners, function as a single evolutionary unit. It highlights the possibility of using beneficial microorganisms, including fungal endophytes, to increase plant growth and productivity by habitat-adapted symbiosis mechanism. According to earlier research, fungal endophytes activate specific physiological traits in crops. However, the specific ways in which these endophytes benefit plants and underlying mechanisms remain unclear. In this context, the objective of this study was to utilize the model system Arabidopsis thaliana to explore possible mechanisms of plant-endophyte interaction. Eight fungal endophytes (K-23, LAS-6, N-14, P-10, P-37, PJ-9, SF-5 and V4-J) previously isolated from extreme habitats were re-examined in terms of their colony morphology. Based on the leads from previous studies, five fungal endophytes (LAS-6, N-14, P-10, PJ-9 and SF-5) were selected and exposed for in vitro co-cultivation with new host A. thaliana. The highest colonisation percentage was observed for the SF-5 (67%) followed by P-10 (33%), LAS-6 (27%) and N-14 (33%), whereas a lower colonisation percentage was observed for PJ-9 (20%). Additionally, these endophytes showed growth promotion activity by improved photosynthetic leaf area, root dry weight and shoot dry weight in fourteen days old Arabidopsis seedlings. The identification of trait-specific endophytes and incorporation of hologenome-enrichment approach can serve as a sustainable and eco-friendly strategy for crop improvement. [ABSTRACT FROM AUTHOR]