Immunoanalysis of dehydrins in Araucaria angustifolia embryos

Abstract

The aim of this study was to describe the dehydrin content of mature Araucaria angustifolia embryos, a species of endangered and economically important conifers, native to southern Brazil, northeastern Argentina, and eastern Paraguay. The A. angustifolia seeds have been categorized as recalcitrant. Dehydrins were studied by western blot analysis and in situ immunolocalization microscopy using antibodies raised against the K segment, a highly conserved lysine-rich 15-amino acid sequence extensively used to recognize proteins immunologically related to the dehydrin family. Western blot analysis of the heat-stable protein fraction, as estimated by 15 % SDS-PAGE, revealed three main bands of approximately 20-, 26-, and 29-kDa; when 17.5 % SDS-PAGE was used, each band resolved into two other bands. Two thermosensitive dehydrin bands of around 16 and 35 kDa were common to the axis and cotyledons, and another thermosensitive band, with molecular mass of approximately 10 kDa, was present in the cotyledons only. Following alkaline phosphatase (AP) treatment, a gel mobility shift was detected for each one of the four main bands that can be due to phosphorylation. Dehydrins were detected in all axis and cotyledon tissues using in situ immunolocalization microscopy. At the subcellular level, dehydrins were immunolocalized in the nuclei, protein bodies, and microbodies. In the nucleus, dehydrins were found to be associated with chromatin. We concluded that the gel mobility shift for the four main bands (probably due to phosphorylation), the presence of thermosensitive bands, and the specific localizations in nuclei and protein bodies provide key starting points to understand the function of dehydrins in the embryo cells of this species.

Structural and Functional Dynamics of Dehydrins: A Plant Protector Protein under Abiotic Stress

“…The localization and functional versatility of dehydrins has been widely studied with respect to plant tolerance against multiple abiotic stresses. Dehydrins are ubiquitously localized in different parts of cells, such as cytoplasm, nucleus, chloroplasts, vacuole, endoplasmic reticulum, mitochondria, cytoplasm and cell membranes [ 9 , 96 , 97 , 98 , 99 , 100 , 101 , 102 ]. Some dehydrins are also found to be localized in several parts of cells under abiotic stresses.…”

Metabolic profile of Brazilian pine embryos and megagametophyte of stored seeds

“…Starch and lipids are among compounds stored in greater quantities in embryos of mature seeds of A. angustifolia (Farias-Soares et al, 2013), but the FTIR spectroscopy results demonstrated that proteinaceous compounds are, quantitatively as important as lipids, and phenolic constituents are also present in large quantities. Regardless of condition, storage resulted in changes in metabolic profile compared to freshly harvested samples.…”

<b>Physiological and physical quality of local <i>Araucaria angustifolia</i> seed variety

“…In recent years, many studies have been conducted to examine seed development and/or somatic/zygotic embryogenesis of A. angustifolia (Balbuena et al, 2009;Agapito-Tenfen, Steiner, Guerra, & Nodari, 2011;Balbuena et al, 2011;Farias-Soares, Burrieza, Steiner, Maldonado, & Guerra, 2013;Rogge-Renner et al, 2013;Shibata, Coelho, & Steiner, 2013;Farias-Soares et al, 2014;Jo, Santos, Bueno, Barbosa, & Floh, 2014;Fraga, Vieira, Puttkammer, Oliveira, & Guerra, 2015;Steiner et al, 2015), and even though knowledge of the botanical varieties of this species has been reported since 1966 by Reitz and Klein (1966), little attention has been devoted to the characterization of these varieties. In this study, the results show a great diversity of the characteristics studied, and knowledge of varieties may contribute to their maintenance and regeneration.…”