Figure 6.

Influence of foliar application of Ca²⁺ on shoot glutathione pool and on the expression of glutathione reductase in sugar beet exposed to drought stress. (A) Shoot GSH concentration; (B) shoot GSSG concentration; (C) shoot GSSH/GSH ratio; and (D) relative BvGR mRNA levels in leaves. Plants were grown in pots for a duration of 8 weeks. Five-week-old sugar beet plants were kept at 90% field capacity as control or exposed to drought stress (30% field capacity) for a duration of 3 weeks. Ca²⁺ was applied at BBCH14 and BBCH18 in concentration of 5 L ha⁻¹ corresponding to 540 g Ca ha⁻¹. Leaves and beetroot were harvested at 60 days after sowing for glutathione analysis. Bars indicate means ± SEM. Different letters denote significant differences according to ANOVA followed by SNK test (p < 0.05; n = 6).