Measuring the Release of Ammonia from Leaves

Ammonia (NH3) is released from the leaves to the atmosphere when atmospheric NH3 concentration is low; in contrast, when atmospheric NH3 concentration is high, NH3 in the atmosphere is absorbed by the leaves. Some previous studies have examined relationships of such NH3 gas exchange with photorespiration, because a NH3 production reaction is involved in the photorespiratory pathway. NH3 compensation point (χNH3) is known as a parameter that represents an NH3 emission potential of the leaves. Two main procedures for determining the χNH3: “gas exchange method” and “apoplast extraction method” are explained in this chapter.