Jasmonic acid conditions

In addition to the higher plants mentioned above, other organisms are also known to possess the jasmonic acid pathway. The green alga Chlorella pyrenoidosa was examined for its ability to metabolise 13(S)-HPOD. The study showed that the Chlorella extracts possessed hydroperoxide dehydrase and other enzymes of the jasmonic acid pathway. However, under normal laboratory conditions for culture growth, neither jasmonic acid nor metabolites of the jasmonic acid pathway were present in Chlorella [40]. 

The esterification reaction of jasmonic acid with methyl alcohol was carried out in a high-pressure reactor to reduce epimerization. It was known that the cis-form of methyl jasmonate easily epimerized to the trans-form of methyl jasmonate under acid, base and high temperature conditions. The resulting methyl jasmonate mixture was recovered and purified by solvent extraction followed by fractional distillation. To improve the methyl epijasmonate concentration, additional steps of fractionation, such as the use of silica gel, were applied. 

Figure 7. Diplodia gossypinaATCC 10936 with hypal growth that is required for the production of jasmonic acid under submerged conditions...

In P. microphyllus model, callus were also subjected to conditions and elicitors in an MS-liquid medium supplemented with 2,4-D as growth regulator [54]. Different nutrient concentration, pH value, type/concentration of elicitors (histidine, threonine and methyl jasmonic acid), and osmotic and salt stress (PEG and NaCl) were evaluated. Light incidence influence was also analyzed. Pilocarpine was released in the liquid medium from callus kept in the dark. Detection was carried out using HPLC-MS/MS techniques, and pilocarpine quantification was performed by HPLC. Elicitors induced highest accumulation of the alkaloid in a time/concentration relationship. Light incidence and methyl jasmonic acid inhibited pilocarpine release to the medium. 

Barley leaf segments respond to the application of (-)-jasmonic acid (JA) or its methylester (JM) as well as to several stress conditions like osmotic stress with the synthesis of so called jasmonate induced proteins (JIPs). Among these proteins is a thionin of 6 kDa, and a protein of 23 kDa with yet unknown function [1]. Beside these results we present evidence on the specific induction of lipoxygenase (LOX) forms in barley leaf segments by jasmonate or by osmotic stress conditions, like incubation with 1 M sorbitol. 

P. microphyllus seedlings were subjugated to different stressing factors and elicitors, such as hypoxia, salt stress, wounding, nutrient (nitrogen/potassium) omission, salicylic acid, and methyl jasmonate [53]. A time of exposure/concen-tration relationship of salicylic acid and methyl jasmonate treatments increased pilocarpine accumulation over control in a fourfold factor. Further conditions on the other hand reduced pilocarpine production. 

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