Core Bacterial Communities in the Endosphere of Lettuce (Lactuca sativa): A Comparative Study of Roots and Leaves

Kazan Federal University, Kazan, 420008, Russian Federation

^* Corresponding author: goolnaz0708@gmail.com

Abstract

This study aimed to compare the endophytic microbiomes of lettuce leaves and roots grown under seven different environmental conditions, varying by substrate type (soil and hydroponics) and method of mineral nutrition. The core microbiome was defined as OTUs (Operational Taxonomic Units) present in all variants of leaves (roots) with a relative abundance > 0.3%. For lettuce leaves, only 4 common bacterial OTUs were identified, belonging to the genera Lactobacillus and Sphingomonas, and the family OPS 17. The core microbiome of lettuce roots included 9 OTUs: Bacteroidetes bacterium, OTUs from the family Obscuribacterales, and genera Reyranella, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Aquabacterium, Pseudomonas, env. OPS 17, and two different genera of Sphingomonas. Notably, Sphingomonas and env.OPS 17 were common to both leaf and root microbiomes. The results underscore the importance of considering both the endosphere and exosphere, as well as different plant parts, in microbiome studies. The distinct microbiomes of leaves and roots highlight the influence of environmental conditions and plant organs on microbial composition. These insights can inform strategies for optimizing plant health and growth through microbiome management, contributing to sustainable agriculture.