Nitric oxide suppresses stomatal opening by inhibiting inward-rectifying K_in⁺ channels in Arabidopsis guard cells

【摘要】 We explore nitric oxide (NO) effect on K+in channels in Arabidopsis guard cells. We observed NO inhib- ited K+in currents when Ca2+ chelator EGTA (Ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid) was not added in the pipette solution; K+in currents were not sensitive to NO when cytosolic Ca2+ was chelated by EGTA. NO inhibited the Arabidopsis stomatal opening, but when EGTA was added in the bath solution, inhibition effect of NO on stomatal opening vanished. Thus, it implies that NO ele- vates cytosolic Ca2+ by activating plasma membrane Ca2+ channels firstly, then inactivates K+in chan- nels, resulting in stomatal opening suppressed subsequently.更多还原

【Abstract】 We explore nitric oxide (NO) effect on K+in channels in Arabidopsis guard cells. We observed NO inhib- ited K+in currents when Ca2+ chelator EGTA (Ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid) was not added in the pipette solution; K+in currents were not sensitive to NO when cytosolic Ca2+ was chelated by EGTA. NO inhibited the Arabidopsis stomatal opening, but when EGTA was added in the bath solution, inhibition effect of NO on stomatal opening vanished. Thus, it implies that NO ele- vates cytosolic Ca2+ by activating plasma membrane Ca2+ channels firstly, then inactivates K+in chan- nels, resulting in stomatal opening suppressed subsequently.更多还原