The Activity of Cell-Wall Modifying β-1,3-Glucanases in Soybean Grown in Presence of Heavy Metals

Abstract

Cell walls represent the first barrier that can prevent the entrance of toxic heavy metals into plants. The composition and the flexibility of the cell wall are regulated by different enzymes. The ß-1,3-glucanases control the degradation of the polysaccharide callose as a flexible regulation mechanism of cell wall permeability and/or its ability to bind metals under stress conditions. The profile and activity of ß-1,3-glucanases in the presence of heavy metals, however, has rarely been studied. Here we studied these enzymes in four soybean varieties (Glycine max) grown in the presence of cadmium ions. These analyses revealed three acidic and one basic enzyme isoforms in each soybean variety, but only two of the acidic isoforms in the variety Moravians were substantially responsive to the presence of Cd 2+ . Since the responses of certain glucanases were detected mainly in the varieties sensitive to metal and accumulating high amounts of metals, we assume their role in the defense rather than strategic metal sequestration.

Variable dynamics of cadmium uptake and allocation in four soybean cultivars

“…2B). Interestingly, this cultivar appears as relatively tolerant to Cd, while under similar conditions we observed lack of induction of defense components such PR protein synthesis (Bardáčová et al 2016) or proline accumulation (this study). In addition, some part of cadmium was transported to the areal parts of plants (Fig.…”

Tissue-Specific Responses in Soybean Plants Exposed to Cadmium

“…Recently, however, several studies have demonstrated the importance of β-1,3-glucanases in the defense of plants against abiotic stresses, such as e.g. drought (Gregorová et al, 2015), low temperature (Goñi et al, 2011;Zur et al, 2013) and heavy metals (Piršelová et al, 2011;Bardáčová et al, 2016;Su et al, 2016). We detected 5 isoforms of total β-1,3-glucanases and 4 isoforms of acidic/neutral β-1,3-glucanases in soybean leaves.…”

“…In general, we observed an increase in β-1,3-glucanase activity in young soybean leaves and contrariwise, a predominant decrease in β-1,3-glucanase activity in mature leaves. The number and activity of β-1,3-glucanase isoforms in individual plant parts depends on many factors, mainly on plant species, cultivar, sensitivity, developmental stage as well as the type, concentration and duration of exposition to the toxic metals and multifunctional character of individual isoforms in plant tissues (Piršelová et al, 2011;Bardáčová et al, 2016). Variability in β-1,3-glucanase activity may be related to plant diversification due to domestication, natural hybridization, and allopolyploidy (Moravčíková et al, 2016).…”