Rice endophyte Pantoea agglomerans YS19 forms multicellular symplasmata via cell aggregation

Area of Science:

• Microbiology
• Bacteriology
• Plant-Bacterial Interactions

Background:

• Pantoea agglomerans is known for forming multicellular symplasmata.
• The mechanism underlying symplasmata formation in P. agglomerans remains unclear.

Purpose of the Study:

• To investigate the formation mechanism of symplasmata in the rice diazotrophic endophyte Pantoea agglomerans YS19.

Main Methods:

• A green fluorescent protein (GFP)-labeled strain, YS19::gfp, was created to track bacterial behavior.
• Growth rates and GFP label stability were assessed for the recombinant strain.
• Co-cultivation experiments were performed by mixing single cells of YS19::gfp and wild-type YS19.

Main Results:

• YS19::gfp exhibited a minimal growth rate decrease (5.5%) and high GFP label stability, comparable to spontaneous mutation rates.
• The recombinant strain YS19::gfp showed similar symplasmata formation and growth profiles to the wild-type YS19.
• Co-cultivation demonstrated that symplasmata were formed by the aggregation of both YS19::gfp and YS19 single cells.

Conclusions:

• Pantoea agglomerans YS19 forms symplasmata primarily through the aggregation of individual cells.
• The findings suggest that symplasmata formation is an aggregation-driven process, not solely dependent on cell proliferation.