Functional sieve element protoplasts

Area of Science:

• Plant Biology
• Cell Biology
• Biophysics

Background:

• Sieve elements (SEs) are vital for long-distance transport in plants.
• Forisomes are unique protein inclusions found in SEs of Fabaceae plants.
• Studying SE membrane properties is challenging due to their complex structure.

Purpose of the Study:

• To isolate and characterize sieve element (SE) protoplasts from Vicia faba.
• To investigate the membrane integrity and electrophysiological properties of SE protoplasts.
• To identify ion channels involved in SE function and signaling.

Main Methods:

• Isolation of SE protoplasts using cell wall-degrading enzymes.
• Assessment of membrane integrity via CFDA staining and osmotic stress response.
• Patch-clamp electrophysiology to study ion channel activity.
• Calcofluor White staining to confirm absence of cell wall remnants.

Main Results:

• Two types of SE protoplasts were successfully isolated: simple and composite twin protoplasts.
• Membrane integrity was confirmed through dye uptake, swelling, and forisome dispersion.
• Patch-clamp studies identified a weak inward-rectifying potassium channel active at physiological voltages.
• The identified channel shares properties with the AKT2/3 channel family in Arabidopsis.

Conclusions:

• SE protoplasts are a viable tool for studying SE membrane biology.
• The identified potassium channel plays a role in SE membrane potential and function.
• This research provides insights into long-distance transport and signaling mechanisms in plants.