Biochemical response of hybrid black poplar tissue culture (Populus × canadensis) on water stress

Abstract

In this study, poplar tissue culture (hybrid black poplar, M1 genotype) was subjected to water stress influenced by polyethyleneglycol 6000 (100 and 200 mOsm PEG 6000). The aim of the research was to investigate the biochemical response of poplar tissue culture on water deficit regime. Antioxidant status was analyzed including antioxidant enzymes, superoxide-dismutase (SOD), catalase (CAT), guiacol-peroxidase (GPx), glutathione-peroxidase (GSH-Px), glutathione-reductase, reduced glutathione, total phenol content, Ferric reducing antioxidant power and DPPH radical antioxidant power. Polyphenol oxidase and phenylalanine-ammonium-lyase were determined as enzymatic markers of polyphenol metabolism. Among oxidative stress parameters lipid peroxidation, carbonyl-proteins, hydrogen-peroxide, reactive oxygen species, nitric-oxide and peroxynitrite were determined. Proline, proline-dehydrogenase and glycinebetaine were measured also as parameters of water stress. Cell viability is finally determined as a biological indicator of osmotic stress. It was found that water stress induced reactive oxygen and nitrogen species and lipid peroxidation in leaves of hybrid black poplar and reduced cell viability. Antioxidant enzymes including SOD, GPx, CAT and GSH-Px were induced but total phenol content and antioxidant capacity were reduced by PEG 6000 mediated osmotic stress. The highest biochemical response and adaptive reaction was the increase of proline and GB especially by 200 mOsm PEG. While long term molecular analysis will be necessary to fully address the poplar potentials for water stress adaptation, our results on hybrid black poplar suggest that glycine-betaine, proline and PDH enzyme might be the most important markers of poplar on water stress and that future efforts should be focused on these markers and strategies to enhance their concentration in poplar.

Variability of tolerance of Wild cherry clones to PEG-induced osmotic stress in vitro

“…A reduction of total phenolic content in Solanum tuberosum L. exposed to drought stress in vitro was noted by Hamooh et al (2021). Results similar to ours were reported by Popović et al (2016) and Popović et al (2017), who found a significant reduction in total phenol content in leaves of Populus × canadensis genotypes at the highest level of osmotic stress (200 mOsm PEG). Finally, our findings supported the results of Roussos (2013), who evidenced the reduction of both total phenolic and flavonols' content as a consequence of the drought effect caused by the presence of mannitol.…”

“…Bettaieb et al (2011) suggested that opposite to the increment of phenolic biosynthesis in mild drought conditions, under severe drought stress, the enzymes involved in their biosynthesis such as phenylalanine ammonia-lyase (PAL) could be partially inhibited, leading to reduced phenolic content. Decreased PAL activity due to drought was observed in Euramerican poplar (Popović et al 2017). Also, Roussos (2013) found that the reduction of both phenolic and flavanols' content was accompanied by accumulation of glucose, mannitol, and pinitol, which mitigated osmotic stress.…”

“…Among them, special attention is given to the detrimental effect of drought-induced oxidative stress which presents the imbalance between reactive oxygen species (ROS) production and antioxidant defense systems (Stajner et al 2013, Vuksanović et al 2019a. Therefore, drought tolerance is intrinsically linked to antioxidant defense mechanisms (Popović et al 2017), and investigation on antioxidant response could indicate more drought tolerant Wild cherry clones. To ameliorate oxidative stress, plants evolved complex enzymatic and non-enzymatic antioxidant systems that can neutralize and scavenge these ROS species and prevent the occurrence of oxidative stress in plants (Wang et al 2019).…”

QTL mapping of physiological traits at the booting stage in rice under low temperature combined with nitrogen fertilization

“…CAT activity was determined using the method described by Gill and Tuteja (2010). One unit of CAT activity was defined as the amount of decreasing enzyme in absorbance of 0.01 per min, which was determined by an ultraviolet absorbance method in A 240 (Popović et al 2017). POD activity was measured by the guaiacol method (Li et al 2000), and one unit activity of which corresponded to the amount of increasing enzyme that decomposes 0.01 of substrate per min.…”

Biochemical and Gene Expression Analyses in Different Poplar Clones: The Selection Tools for Afforestation of Halomorphic Environments

“…High levels of sodium ions (Na + ) are toxic to plants because of their adverse effects on cellular metabolism and ion homeostasis [18][19][20]. Therefore, maintaining high and low levels of Na + in the cell, specifically in the cytoplasm, is essential for plants [19,21]. Various plant genetic strategies have been proposed to solve the salinity issue in the climate change context.…”