高等植物感受外界環境或化學訊號後，會經由起始訊號傳遞系統引起一連串的生理變化，包括鈣離子增加及膜的去極化。學者們在研究離層酸（abscisic acid, ABA)對保衛細胞的影響，提出離子孔道調節氣孔開張的假說，亦即陰離子孔道伴隨著鈣離子孔道是控制氣孔開閉的速率決定因子，進而導致鉀離子孔道活化，使鉀離子外流，膨壓降低，造成氣孔亦會被活化，使液泡中鉀及鈣離子釋放至細胞質中。而離層酸的訊號，可同時由鈣離子及非鈣離子來傳遞。目前研究顯示，光敏素可能是訊號系統的最起始物質。Higher plants perceive environmental and chemical signals via initiation of signal transduction, leading to modification of cellular activity, including Ca2+ uptake and membrane depolarization. Experiments involving the effect of abscisic acid to guard cells, suggesting anion channels, along with Ca2+ channels, play critical and ratelimiting roles. Furthermore, they trigger K+ channel activity, leading to K+ efflux, turgor reduction, and result in stomata closing. In addition, during stomata closing, K+, Ca2+ channels of tonoplast are activated in guard cells, that allow K+, Ca2+ release to cytosol. Otherwise, ABA-induced signals appear to proceed through parallel Ca2+-dependent and Ca2+-independent pathway. Recent studies in our understanding have show that phytochrome may be the furthest upstream component identified to date in the signaling pathway
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.