Influence of temperature stress on the mass share of chlorophyll, lycopene, carotenoids and porphyrins in broccoli

Climate change is a global problem that has changed both the physiological and biochemical parameters of plants. Considering that plants are sessile organisms, their survival depends on the effective activation of metabolic mechanisms of resistance to such stress. As part of this study, we investigated the impact of low and high temperature water on the content of chlorophyll, lycopene, carotenoids and porphyrins in broccoli (Brassica oleracea L. convar. botrytis (L.) Alef. var. cymosa Duch.). For all pigments, except chlorophyll a, a statistically significant difference was observed between the group treated with water of high temperature and the remaining two groups (control and group treated with water of low temperature). In the group treated with water of high temperature, the highest proportion of chlorophyll b (5.35 ± 0.34 mg/g of dry weight (sm)), lycopene (0.28 ± 0.016 mg/g sm), and porphyrins (28.27 ± 1.09 mg/g sm) was recorded. The proportion of carotenoids, on the other hand, was the lowest in this group (0.40 ± 0.19 mg/g sm). Based on this, we conclude that chlorophyll b, lycopene, porphyrins and carotenoids of broccoli are significantly more sensitive to high temperature water stress than to low temperature water.