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Pfaffia glomerata (Spreng.) Pedersen is a medicinal species of great interest because it produces the phytoecdysteroid 20-hydroxyecdysone (20E). Generally, because of atypical growing conditions, in vitro propagated plants function less efficiently as autotrophs and have poorly developed morphological structures. This study analyzed the autotrophic potential of P. glomerata propagated in vitro and evaluated the influence that this has on 20E biosynthesis. Physiological and structural parameters of plants subjected to heterotrophic, photomixotrophic and photoautotrophic growth conditions were evaluated. Levels of 20E were measured by HPLC. Plants were acclimatized in a mixture of soil, sand and substrate, in a greenhouse. Conditions that provided higher carbon input led to an increase in plant growth, and the presence of sucrose was critical, in closure systems without a gas permeable membrane, for normal anatomical development of the micropropagated plants. The absence of sucrose increased photosynthesis and conditions that enhanced photoautotrophy induced greater levels of 20E. The increase of 20E levels by the photoautotrophic system offers new prospects for increasing the commercial production of this species, and for studies that could elucidate the biosynthetic pathway of phytoecdysteroids in plants.

Araucaria angustifolia is an endangered Brazilian native conifer tree. The aim of the present work was to identify differentially expressed proteins between mature and germinated embryos of A. angustifolia, using one and two dimensional gel electrophoresis approaches followed by protein identification by tandem mass spectrometry. The identities of 32 differentially expressed protein spots from two dimensional gel maps were successfully determined, including proteins and enzymes involved in storage mobilization such as the vicilin-like storage protein and proteases. A label free approach, based on spectral counts, resulted in detection of 10 and 14 mature and germinated enriched proteins, respectively. Identified proteins were mainly related to energetic metabolism pathways, translational processes, oxidative stress regulation and cellular signaling. The integrated use of both strategies permitted a comprehensive protein expression overview of changes in germinated embryos in relation to matures, providing insights into the this process in a recalcitrant seed species. Applications of the data generated on the monitoring and control of in vitro somatic embryos were discussed.

The (Spd + Spm) : Put ratio could be used as a marker for germination completion. The increase in IAA levels, prior to germination, could be associated with variations in PA content. The ABA mobilization observed in the embryos could represent a greater resistance to this hormone in recalcitrant seeds, in comparison to orthodox seeds, opening a new perspective for studies on the effects of this regulator in recalcitrant seeds. The gymnosperm seed, though without a connective tissue between megagametophyte and embryo, seems to be able to maintain communication between the tissues, based on the likely transport of plant growth regulators.