Potassium (K+) and calcium (Ca2+) ions are important for stomatal function in seed plants, however little is known about the contributions of these ions in the stomata of bryophytes and early-branching vascular plants. Voss et al. focus on how fern stomata regulate ion transport. Injection of K+ into guard cells (GC) activated outward ion channels, similar to what is seen in Arabidopsis. Voltage pulses preferentially activated Ca2+ release from sources closest to the microelectrode, triggering a rise in cytosolic Ca2+ levels. Interestingly, a fluorescent Ca2+ reporter was seen to move from one impaled GC into the adjacent GC, thus identifying interconnectedness of the cytosol of the GCs. This diffusion was slow and limited, suggestive of plasmodesmata, whose presence were confirmed by electron microscopy. These plasmodesmata act differently than the cell wall gap connecting GC in grasses, which does allow for rapid exchange of fluorescent dyes. On the other hand, voltage-dependent ion channels appear similar amongst varying species (Summary by Alecia Biel) New Phytol. 10.1111/nph.15153.
You might also like
Another Step Closer to Understanding Plant Cell Wall Biosynthesis: The Crystal Structure of FUCOSYLTRANSFERASE1[
Hydration-dependent phase separation of a prion-like protein regulates seed germination during water stress (bioRxiv)
Distinct sets of tethering complexes, SNARE complexes, and Rab GTPases mediate membrane fusion at the vacuole in Arabidopsis (PNAS)
GABA signalling modulates stomatal opening to enhance plant water use efficiency and drought resilience (Nature Comms)