Postharvest jasmonic acid and methyl jasmonate dip treatments alleviate chilling injury and maintain quality of cold-stored 'Black Amber' and 'Tegan Blue' Japanese plums (Prunus salicina Lindell).

Background: Chilling injury (CI) in Japanese plums (Prunus salicina Lindell) is a critical cold storage constraint that adversely impacts fruit quality and marketability. Jasmonic acid (JA) and its methyl derivative 'methyl jasmonate' (MeJA) are widely studied phytohormones for the mitigation of CI in several fruit crops, whereas their efficacy in Japanese plums remains unexplored. Freshly harvested 'Black Amber' and 'Tegan Blue' plums were dipped for 1 min in 0 (control), 25, 75 or 250 ppm of aqueous solutions/emulsion of jasmonic acid (JA), methyl jasmonate' (MeJA) and the ethylene precursor aminocyclopropane-1-carboxylic acid (ACC), and cold stored for 14 and 28 days followed by 1 and 2 days under shelf conditions.

Salicylate activity. 3. Structure relationship to systemic acquired resistance.

Salicylic acid (2-hydroxybenzoic acid; SA) is a primary signal inducing plant defenses against pathogens. This plant disease resistance, known as systemic acquired resistance (SAR), is an attractive target for the development of new plant protection agents. SAR induction is a multistep process that includes accumulation of pathogenesis-related (PR) proteins.

Salicylate activity. 2. Potentiation of atrazine.

Atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine] inhibits photosystem II (PSII) and is commonly used to control weeds in maize. It has been found that addition of sodium salicylate (sodium 2-hydroxybenzoate; NaSA) increased the postemergence herbicidal activity of atrazine against dicotyledonous weeds. NaSA also potentiated the activity of bentazon, another PSII-inhibiting herbicide.

Salicylate activity. 1. Protection of plants from paraquat injury.

Paraquat (1,1'-dimethyl-4,4'-bipyridinium; methylviologen) is a widely used, nonselective contact herbicide that rapidly stimulates free radical generation. It has been found that the addition of sodium salicylate (sodium 2-hydroxybenzoate; NaSA) to paraquat spray solutions significantly decreased herbicidal activity. This protection was observed in tobacco (Nicotiana tabacum) regardless of whether NaSA was foliar-applied along with or prior to paraquat application or NaSA was soil-applied prior to paraquat application.