Trans-jasmonic acid (JA), cis-JA, and trans-methyl jasmonate (MeJA) were quantified in pulp and seeds of `Tsugaru' apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] and `Satohnishiki' sweet cherry (Prunus avium L.). Trans-JA and cis-JA showed similar changes during development in both types of fruit. JA concentration was high in the early growth stages of apple pulp development, decreased with days after full bloom (DAFB), and then increased again during maturation. There was an initial decrease in concentration of MeJA in apple pulp, followed by a general increase towards harvest. Concentrations of JA and MeJA in the pulp of sweet cherry were high during early growth stages, then decreased towards harvest. PDJ treatment at 104 DAFB (preclimacteric stage) increased endogenous abscisic acid concentration and anthocyanin concentration at 122 and 131 DAFB (maturation stages) in apple. JA concentration in apple seeds was also high in the early growth stages, then decreased, and finally peaked at harvest. MeJA concentration in apple seeds increased towards harvest. In the seeds of sweet cherry, JA and MeJA concentrations generally increased until harvest. In both types of fruit, concentrations of JA and MeJA in the seeds were higher than those of pulp. On a dry weight basis, changes in concentration in the seeds preceded those in the pulp. These results demonstrate that relatively high amounts of JA and MeJA are associated with young developing fruit. These substances may have a role in regulation of fruit growth at early growth stages, though this has not been demonstrated. Chemical name used: n-propyl dihydrojasmonate (PDJ).
Satoru Kondo, Akihiro Tomiyama, and Hideharu Seto
Satoru Kondo, Futoshi Yazama, Kasinee Sungcome, Sirichai Kanlayanarat, and Hideharu Seto
Jasmonic acid (JA) and methyl jasmonate (MeJA) were quantified in the skin, pulp, and seeds of `Nam Dok Mai' and `Nang Klangwan' mangoes (Mangifera indica L.). JA showed similar changes during development in both cultivars of fruit. JA concentrations were high in the early growth stages of skin and pulp development, decreased with days after full bloom (DAFB), and then increased again during ripening. JA concentrations in the skin were higher than those in the pulp. 1-aminocyclopropane-1-carboxylic acid (ACC) concentrations in the skin and pulp of both cultivars increased toward harvest. Differing with JA, ACC concentrations in the pulp were high compared with the skin. This fact suggests that although JA and ACC are associated with the ripening of mangoes, they may play different roles. JA concentrations in the seeds of both cultivars decreased toward harvest, possibly suggesting a lack of dormancy in mango seeds. Changes in jasmonates during storage were also examined. JA content in the skin and pulp increased in stored fruit. In addition, the increase in JA content was largest in fruit that lost the most fresh weight. This suggests that JA accumulation that occurs during fruit senescence is associated with moisture loss.