Enhancement of Vindoline and Catharanthine Accumulation, Antioxidant Enzymes Activities, and Gene Expression Levels in Catharanthus roseus Leaves by Chitooligosaccharides Elicitation

Abstract

Catharanthus roseus (L.) G. Don is a plant belonging to the genus Catharanthus of the Apocynaceae family. It contains more than one hundred alkaloids, of which some exhibit significant pharmacological activities. Chitooligosaccharides are the only basic aminooligosaccharides with positively charged cations in nature, which can regulate plant growth and antioxidant properties. In this study, the leaves of Catharanthus roseus were sprayed with chitooligosaccharides of different molecular weights (1 kDa, 2 kDa, 3 kDa) and different concentrations (0.01 μg/mL, 0.1 μg/mL, 1 μg/mL and 10 μg/mL). The fresh weights of its root, stem and leaf were all improved after chitooligosaccharides treatments. More importantly, the chitooligosaccharides elicitor strongly stimulated the accumulation of vindoline and catharanthine in the leaves, especially with the treatment of 0.1 μg/mL 3 kDa chitooligosaccharides, the contents of them were increased by 60.68% and 141.54%, respectively. Furthermore, as the defensive responses, antioxidant enzymes activities (catalase, glutathione reductase, ascorbate peroxidase, peroxidase and superoxide dismutase) were enhanced under chitooligosaccharides treatments. To further elucidate the underlying mechanism, qRT-PCR was used to investigate the genes expression levels of secologanin synthase (SLS), strictosidine synthase (STR), strictosidine glucosidase (SGD), tabersonine 16-hydroxylase (T16H), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT), peroxidase 1 (PRX1) and octadecanoid-responsive Catharanthus AP2-domain protein 3 (ORCA3). All the genes were significantly up-regulated after chitooligosaccharides treatments, and the transcription abundance of ORCA3, SLS, STR, DAT and PRX1 reached a maximal level with 0.1 μg/mL 3 kDa chitooligosaccharides treatment. All these results suggest that spraying Catharanthus roseus leaves with chitooligosaccharides, especially 0.1 μg/mL of 3 kDa chitooligosaccharides, may effectively improve the pharmaceutical value of Catharanthus roseus.

Hairy roots: An untapped potential for production of plant products

“…Chitin is a major cell wall constituent of fungus (Liaqat and Eltem, 2018) Chitooligosaccharides derived from chitin are elicitors of innate immune defense against fungal pathogens. Treatment of C. roseus leaves using 0.1 mg/ml of a 3 kDa molecular weight commercially available chitooligosaccharide extraction led to an increase of the vinblastine precursors vindoline and catharanthine of 60.68 and 141.54% (Tang et al, 2022). In C. roseus cambial meristematic cell cultures adding 25 mg/l mycelium elicitor from the fungus Aspergillus flavus resulted in fold increases of 1.45 for vindoline, 3.29 for catharanthine, and 2.14 for ajmaline (Liang et al, 2018).…”

The use of chitosan oligosaccharide to improve artemisinin yield in well-watered and drought-stressed plants

“…Moreover, several studies showed that the use of COS is a promising option to increase the production of secondary metabolites with pharmacological significance. Thus, COS improved the pharmaceutical value of Catharanthus roseus (L.) G. Don by increasing the content of vindoline and catharanthine in the leaves, and by increasing the fresh weight of roots, stems and leaves (Tang et al, 2022). Moreover, greek oregano (Origanum vulgare ssp.…”

The Genome-Wide Identification, Characterization, and Expression Analysis of the Strictosidine Synthase-like Family in Maize (Zea mays L.)

“…catalyzes the synthesis of strictosamide (STR) from geraniol diphosphate and tryptamine in cytoplasm [8,9]. Previous research has shown that chitooligosaccharides, the only positively charged basic amino oligosaccharides in nature, can induce the expression of STR and other genes, thereby improving the drought tolerance and yield of plants [10][11][12].…”