Plants, cactus, mushrooms, etc are more complex living organisms than slime so analysis of their electrical signals is challenging. Bespoke signal processing software can be used to aid analysis.
Signal analysis software
Details of SignalPlant (free to download analysis software) available here.
Plants electrical signals can be converted into sounds & music. See here for example tracks.
Plant image analysis
Free plant image analysis software can be downloaded by clicking here.
The PLEASED project (funded by EU) has researched into plant signals, click here for details.
For an integrated view of plant signaling click here.