Difference between transpiration and diffusion (significance in plants)?
Answers
I presume that the OP does not mean the diffusion of plants but the diffusion of water vapor, CO2, and O2 from plant leaves.
In sunlight the concentration of water and oxygen molecules just inside the stomata is higher than the concentration of the air around the leaves so water vapor and oxygen diffuse, or move out, from the leaves through the stomata. The concentration of CO2 is higher outside the leaves than inside so CO2 diffuses into the leafs through the stomata. This is the diffusion.
Photosynthesis cleaves CO2 releasing O2 and uses the carbon to make sugars thus maintaining a lower concentration inside the leaves than out and drive the diffusion of CO2 in and diffusion of O2 out. The tissues around the chloroplasts are wet with water that moves up from the roots through the trunk and stems in a continuous tiny columns of water through hollow connected cells that are very hydrophilic. In the chloroplasts water is cleaved for its hydrogen, most of the oxygen released diffuses out of the leaves and is replace by water moving up the stems and trunk. This is a sketchy description of transpiration.
Diffusion, then, is a physical driver of transpiration.