Neither lysigenous nor just oil: Demystifying myrtaceous secretory cavities.

Autor: Richit JF; Laboratory of Plant Anatomy, Department of Botany, Institute of Biosciences, Federal University of Rio Grande do Sul, Bento Gonçalves Avenue, 9500, Porto Alegre, Rio Grande do Sul, Brazil., Díaz SVN; Electrochemical Processes and Corrosion Laboratory, Department of Metallurgy, School of Engineering, Federal University of Rio Grande do Sul, Bento Gonçalves Avenue, 9500, Porto Alegre, Rio Grande do Sul, Brazil., Dick LFP; Electrochemical Processes and Corrosion Laboratory, Department of Metallurgy, School of Engineering, Federal University of Rio Grande do Sul, Bento Gonçalves Avenue, 9500, Porto Alegre, Rio Grande do Sul, Brazil., Mariath JEA; Laboratory of Plant Anatomy, Department of Botany, Institute of Biosciences, Federal University of Rio Grande do Sul, Bento Gonçalves Avenue, 9500, Porto Alegre, Rio Grande do Sul, Brazil.
Jazyk: angličtina
Zdroj: American journal of botany [Am J Bot] 2023 Nov; Vol. 110 (11), pp. e16248. Date of Electronic Publication: 2023 Nov 14.
DOI: 10.1002/ajb2.16248
Abstrakt: Premise: Leaf subepidermal secretory cavities are a notable trait in Myrtaceae, but their formation is still controversial because of the lack of consensus on their ontogeny among authors. Knowledge about the compounds present in these cavities has grown over the last few years, demonstrating that terpenoid-rich oils are not their unique content. These two points are the focus of this study on the ontogeny, structure, and contents of secretory cavities in neotropical Myrtaceae.
Methods: We used histochemical tests and Raman analysis to verify the basic chemical composition of the cavity contents of nine species. We studied the ontogeny of glands in one species, comparing aldehyde-fixed tissues and fresh sections mounted in an inert medium.
Results: We observed schizogenous development and appearance of the secretory cavities and found that sample processing may induce cell breakdown, which can be misinterpreted as lysigeny. The content of these cavities contains putative terpenes, resins, carbonyl groups, and flavonoids.
Conclusions: Our findings support the hypothesis that the lysigenous appearance of the oil glands is a technical artifact. These tissue distortions must be considered when interpreting the development of this type of secretory structure. Moreover, the basic analyses of chemical constituents show for the first time that the glands of neotropical Myrtaceae are potential reservoirs of some compounds such as flavonoids previously reported as novelties for a few other myrtaceous species. Because some of them are non-lipid compounds, the idea that the glands are just oil repositories is no longer applicable.
(© 2023 Botanical Society of America.)
Databáze: MEDLINE
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