THE ROLE OF NITRIC OXIDE IN DIATOM ADHESION IN RELATION TO SUBSTRATUM PROPERTIES(1)

Area of Science:

• Marine biology
• Environmental science
• Biophysics

Background:

• Diatom adhesion, crucial for survival and biofilm formation, is influenced by surface properties.
• Understanding how diatoms perceive and respond to substratum wettability is key to controlling biofouling.

Purpose of the Study:

• To investigate the role of nitric oxide (NO) in Seminavis robusta's differential adhesion to hydrophobic and hydrophilic surfaces.
• To test the hypothesis that NO acts as a stress response signaling molecule related to surface perception.

Main Methods:

• Single-cell imaging using DAF-FM DA to quantify NO levels in diatoms on different surfaces.
• Experimental manipulation of NO levels using donors (SNAP) and inhibitors (NMMA) to assess effects on adhesion.
• Comparative adhesion strength measurements on hydrophilic (glass) and hydrophobic (PDMSE) surfaces.

Main Results:

• Seminavis robusta exhibited significantly higher NO levels (4-fold) on hydrophilic glass compared to hydrophobic PDMSE.
• Elevated NO levels reduced diatom adhesion strength to both surface types.
• Inhibition of NO production led to a modest but significant increase in adhesion strength.

Conclusions:

• Nitric oxide (NO) functions as a signaling molecule mediating Seminavis robusta's perception of surface wettability.
• NO production appears to be a stress response to unfavorable hydrophilic surfaces, modulating adhesion.
• Findings provide insights into diatom-surface interactions and potential anti-fouling strategies.