Seed-vectored endophytic bacteria modulate development of rice seedlings

Area of Science:

• Microbial Ecology
• Plant Science
• Agronomy

Background:

• Rice seeds harbor indigenous endophytic bacteria.
• These bacteria play crucial roles in plant development and defense.

Purpose of the Study:

• To evaluate the impact of removing indigenous bacteria from rice seeds on seedling growth.
• To identify the specific roles of these bacteria in plant development and pathogen defense.

Main Methods:

• Surface sterilization and antibiotic treatment to remove seed-associated bacteria.
• 16S rDNA sequencing for bacterial identification.
• Reinoculation experiments to confirm bacterial function.

Main Results:

• Absence of bacteria led to reduced seedling growth, including root hair development and overall size.
• Endophytic bacteria were found to be intracellular in root cells.
• Isolated bacteria (Enterobacter asburiae, Pantoea dispersa, Pseudomonas putida) produced indole acetic acid, inhibited Fusarium oxysporum, and solubilized phosphate.
• Reinoculation restored seedling growth and development.

Conclusions:

• Rice seeds naturally host bacterial endophytes that significantly influence seedling development.
• These endophytes modulate shoot and root lengths, root hair formation, and disease susceptibility.