The concerned research aimed to investigate the peculiarities of adaptation to water regime and photosynthetic activity in four dye-yielding plant species (Indigofera tinctoria L., Rubia tinctorum L., Isatis tinctoria L., and Lawsonia inermis L.) cultivated in the Surkhandarya Region, Uzbekistan. During the study, the leaf cell sap (LCS) concentration and content of the key photosynthetic pigments, such as chlorophylls a and b, total pigment concentration, and carotenoids, succeeded in their determination at the budding stage under normal and water-deficit conditions. The obtained results allowed for identifying the degree of osmotic adaptation and photoadaptation mechanisms of the plants under water-deficit conditions. The results lay down a scientific base for assessing the ecological stability of dye-yielding plants and determining cultivars resistant to water stress conditions with increasing photosynthetic efficiency. Detecting the chlorophylls a and b and carotenoid contents in leaf samples used the spectrophotometric method. The results revealed a considerable decline in photosynthetic pigments’ concentration under water-deficit conditions; however, these also showed robust adaptive processes in certain species (especially the species Indigofera tinctoria L.). Biochemical analysis disclosed an increase in the anthocyanin and flavonoid contents, ensuring stress tolerance in dye-yielding plants. This approach helps in distinguishing the degree of plant adaptability with enhanced efficiency in natural pigments’ production.
Dye-yielding plants, natural dye, species, physiology, photosynthetic pigments, chlorophyll a and b, carotenoid, cell sap, water-deficit conditions
The dye-yielding plant species (Indigofera tinctoria L., Rubia tinctorum L., Isatis tinctoria L., and Lawsonia inermis L.) exhibited distinct physiological responses to water-deficit conditions. The species Rubia tinctorum L. and Lawsonia inermis L. showed higher cell sap concentrations, suggesting a considerable capacity for drought adaptation.