In: Biology
Guard cells function as multisensory hydraulic valves. Environmental factor like light intensity, humidity, temperature, intracellular CO2 concentration are sensed by guard cells and these signals are integrated in to stomatal reponses.
when guard cells absorb water and swells up, making it turgid and stomata opens. while when guard cells losses water and become flaccid and the stomata closes.
Some plants can uptake nutrients present in the atmosphere with the help of stomata. By the mechanism called hydrolic activation of stomata, presence of humidity causes the stomata to open. then the nutrients that are present on the leaves surface are absorbed and transported in to leaf apoplast.