W. Dathe et al., UPTAKE OF JASMONIC ACID AND RELATED-COMPOUNDS BY MESOPHYLL PROTOPLASTS OF THE BARLEY LEAF, Journal of plant growth regulation, 12(3), 1993, pp. 133-140
Jasmonic acid (JA) permeates the plasma membrane of mesophyll cells by
diffusion as the lipophilic undissociated JAH molecule probably witho
ut the participation of a saturable uptake component. The mesophyll pl
asma membrane is nearly impermeable to the JA anion. The permeability
coefficients of JA and several JA derivatives (its methy ester (JAMe),
7-iso-cucurbic acid (7-iso-CA), 6-epi-7-iso-cucurbic acid (6-epi-7-is
o-CA), and both stereoisomers of the JA leucine conjugate ((+)-JA-Leu
and (-)-JA-Leu)) were determined and used in a simplified mathematical
model to predict stress-dependent JA redistribution between cytosol a
nd apoplast in comparison with ABA. The redistribution of JA takes pla
ce similar to ABA; however, its velocity is much higher because of the
high JA membrane permeability. When the permeability coefficients for
the mesophyll plasma membrane are plotted double-logarithmically agai
nst the ratio of the distribution coefficient and the molecular ratio
to the power of 1.5 (K(D)M(r)(-15)), two straight lines result for two
different classes of compounds. The permeability coefficients of JA c
onjugates are lower than that of the free acid by approximately one or
der of magnitude, but they are still significantly higher than that of
ABA.