Bacterial seed endophytes: genera, vertical transmission and interaction with plants

Abstract: The seed, a vital plant organ for its continuation, contains microbial endophytes that develop as part of the early plant microbiome and assist growing seedlings in various ways. In this study, bacterial endophytes from seeds of wheat cultivars grown under different agro-ecological conditions were genotypically and functionally analyzed. Despite environmental differences and cultivars adapted to distinct agroclimatic zones, the endophytic bacterial count ranged from 2.79 to 5.19 Log CFU/g. The dominant seed bacteria belonged to the phylum Firmicutes, with diverse members of the genus Bacillus . There were core and niche-specific bacteria among the different agroclimatic zones. The seed endophytic bacteria exhibited hydrolytic enzyme activities, mainly amylase, cellulase, and xylanase. The nitrogen fixation capacity ranged from 0.81 to 32.06 nmol ethylene h −1 mg −1 protein, while phosphate solubilisation ranged from 147 to 440 μg mL −1 . Some seed endophytes from the North Western Plains Zone (NWPZ) showed strong antagonism toward Fusarium graminearum (52%), Bipolaris sorokiniana (35.9%), and Tilletia indica (43.4%). The green fluorescent protein (GFP)-tagged endophytic bacteria, when reintroduced to wheat seeds, were observed to colonize and migrate within germinating seedlings, Confirm their potential for internal establishment and movement within the host. These seed endophytic bacteria may offer notable benefits by colonizing root tissues during germination, thereby enhancing plant growth and yield.

TL;DR: Endophytic bacteria protect plants against pathogens by direct and indirect mechanisms, including hormone production, nutrient solubilization, and suppression of disease.

TL;DR: Exploration and characterization of bacterial endophytes from diverse environment conditions producing novel bioactive compounds, have promising applications in medicine, agriculture, and veterinary sciences, enabling us to counter health challenges in ecofriendly manner.

TL;DR: Successive cultivation under drought selects for specific microbiome members in wheat rhizosphere, with Stenotrophomonas and Rahnella emerging as key genera under different selection regimes, but single inoculum of these genera does not improve drought resilience in wheat.

TL;DR: The individual steps of plant colonization are described and the known mechanisms responsible for rhizosphere and endophytic competence are surveyed to better predict how bacteria interact with plants and whether they are likely to establish themselves in the plant environment after field application as biofertilisers or biocontrol agents.

TL;DR: The results indicate that plants have different abilities to influence their abundance by changing the structure of their soil communities, and that this is an important regulator of plant community structure.

TL;DR: Molecular analysis showed that plant defense responses limit bacterial populations inside plants, and delivery of endophytes to the environment or agricultural fields should be carefully evaluated to avoid introducing pathogens.