This demonstrates unambiguously that HPLF was acti vated in the presence of lipid bodies. Discussion Volatile aldehydes, produced by the action of HPL are an essential component of plant oxylipin metabolism, choose size and play an important role in the plant environment interac tion. Most results obtained to date refer to members of the CYP74B subfamily, which includes 13 HPLs that are expressed in aerial tissues and associated with plastids. In the case of HPLE, we have similarly shown Inhibitors,Modulators,Libraries that the full length sequence was able to route YFP to plastids in tran siently transformed tobacco protoplasts and leaves. The fluorescence patterns observed during transient expres sion of HPLE1 YFP were similar to those recently reported for potato HPL and AOS enzymes, where the correspond ing GFP tagged chimeras resulted in fluorescent dots asso ciated with thylakoid membranes .

Further experiments are in progress to verify if M. truncatula HPLE can share a similar localisation inside the plastids. We have presented new data on the subcellular distribu tion of 9 13 HPLs belonging to the CYP74C subfamily. 9 13 HPLs were initially Inhibitors,Modulators,Libraries thought to be restricted to the Cucurbitaceae family, but their occurrence in other plant species, such as Medicago spp. and rice have been reported only recently. Transient expression in tobacco protoplasts and leaves, of YFP tagged HPLF enabled us to carry out a detailed localisation of this enzyme. Our results indicated that a cytosolic distribution of fluores cence co exists with the fluorescence associated with small spherical organelles.

In previous work we showed that another member of the CYP74C sub family, a 9 HPL from almond seed, asso ciates with similar organelles even though it was mainly localised in the microsomes. In this context, the localisa tion pattern of the almond 9 HPL differs Inhibitors,Modulators,Libraries significantly from the cytosolic distribution of HPLF and this is the first report showing such a localisation Inhibitors,Modulators,Libraries for HPL. In the present work, we first showed, by co localisation experiments either with oleosin GFP Nile red and oleosin RFP GFP KDEL, that oleosins, when ectopically expressed in tobacco protoplasts, are specifi cally targeted to lipid droplets. LD consist of a core of neutral lipids surrounded by a surface monolayer of phospholipids and form from specific ER sub compart ments, where neutral lipids are synthesised and accumu lated and.

Western blot analyses indicated a main microsomal localisation for oleosin, when expressed in tobacco protoplasts. Together with the confocal images shown in Fig. 4a and 4b, these results could indicate that, in such a system, LD are mainly connected to the ER. A support to this interpre tation may come from studies in animals, Inhibitors,Modulators,Libraries where they have been extensively studied selleck chem as a fundamental components of intracellular lipid homeostasis.