[1] Shown in the picture below is the proposed model for the active site of LAP-A in tomato based on the work of Strater et al.[2] It is also known that the biochemistry of the LAPs from these three kingdoms is very similar.

In order to survive, plants must be able to respond to many biotic and abiotic stresses, including pathogen attack, piercing/sucking insects, herbivory, and mechanical wounding.

Similar to mechanical wounding, chewing insects, such as the tobacco hornworm (Manduca sexta, one of the major pests of tomato), cause extensive tissue damage activating the jasmonic acid (JA)-mediated response (Walling 2000).

Products of late-response genes act as deterrents to chewing-insect feeding, often by decreasing the nutritional value of the food ingested or interfering with insect gut function (Walling 2000).

For example, serine proteinase inhibitors (Pins) interfere with digestive proteases in the insect gut and polyphenol oxidases (PPO) act to decrease the nutritive value of plant leaves after ingestion by herbivores (Johnson et al. 1989; Ryan 2000; Orozco-Cardenas 2001).

(LAP-A), a product of the octadecanoid pathway in some solanaceous plants, has been shown by Fowler et al. to have a regulatory role in the late wound response of tomato.

LAP proteins are expressed in a variety of marine organisms as a method of coping with the osmotic threat high salinity poses to the cell.