AUTHOR=Hazubska-Przybył Teresa , Obarska Agata , Konecka Agata , Kijowska-Oberc Joanna , Wawrzyniak Mikołaj Krzysztof , Piotrowska-Niczyporuk Alicja , Staszak Aleksandra Maria , Ratajczak Ewelina 

TITLE=Modulating ascorbic acid levels to optimize somatic embryogenesis in Picea abies (L.) H. Karst. Insights into oxidative stress and endogenous phytohormones regulation

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 15 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1372764

DOI=10.3389/fpls.2024.1372764

ISSN=1664-462X

ABSTRACT=Global warming has adversely affected Picea abies (L.) H. Karst. forests in Europe, prompting a need for innovative forest breeding strategies. Somatic embryogenesis (SE) offers promise but requires protocol refinement. Understanding the molecular mechanisms governing somatic embryo development is essential, and oxidative stress plays a crucial role in SE regulation.Ascorbic acid (ASA), a vital antioxidant, can potentially control oxidative stress. In the present study, we normalized ASA concentrations in induction and proliferation media to enhance the embryogenic tissue (ET) regeneration and proliferation capacity of mature explants. Media were supplemented with ASA at 0, 25, 50, 100 and 200 mg l -1 . Accumulation of hydrogen peroxide (H2O2) and endogenous phytohormones, including auxins, cytokinins, brassinosteroids, abscisic acid and gibberellin, in nonembryonic calli and ET was measured.Subsequently, their impact on ET induction and multiplication was analysed. Our results demonstrate that application of ASA at concentrations of 25 and 200 mg l -1 led to increased H2O2 levels, potentially inducing oxidative stress while simultaneously reducing levels of all endohormone groups. Notably, the highest ET induction frequency, approximately 70%, was observed with ASA at 50 mg l -1 . These findings will enhance SE induction procedures, particularly in more resistant explants, underscoring the significance of ASA application in culture media.