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. 2023 Jun 2:14:1200898.
doi: 10.3389/fpls.2023.1200898. eCollection 2023.

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

Ana L García-García  1   2 , Ana Rita Matos  3   4 , Eduardo Feijão  5 , Ricardo Cruz de Carvalho  3   5   6 , Alicia Boto  1 , Jorge Marques da Silva  4 , David Jiménez-Arias  7
Affiliations

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

Ana L García-García et al. Front Plant Sci. .

Abstract

Introduction: Artemisinin is a secondary metabolite well-known for its use in the treatment of malaria. It also displays other antimicrobial activities which further increase its interest. At present, Artemisia annua is the sole commercial source of the substance, and its production is limited, leading to a global deficit in supply. Furthermore, the cultivation of A. annua is being threatened by climate change. Specifically, drought stress is a major concern for plant development and productivity, but, on the other hand, moderate stress levels can elicit the production of secondary metabolites, with a putative synergistic interaction with elicitors such as chitosan oligosaccharides (COS). Therefore, the development of strategies to increase yield has prompted much interest. With this aim, the effects on artemisinin production under drought stress and treatment with COS, as well as physiological changes in A. annua plants are presented in this study.

Methods: Plants were separated into two groups, well-watered (WW) and drought-stressed (DS) plants, and in each group, four concentrations of COS were applied (0, 50,100 and 200 mg•L-1). Afterwards, water stress was imposed by withholding irrigation for 9 days.

Results: Therefore, when A. annua was well watered, COS did not improve plant growth, and the upregulation of antioxidant enzymes hindered the production of artemisinin. On the other hand, during drought stress, COS treatment did not alleviate the decline in growth at any concentration tested. However, higher doses improved the water status since leaf water potential (YL) improved by 50.64% and relative water content (RWC) by 33.84% compared to DS plants without COS treatment. Moreover, the combination of COS and drought stress caused damage to the plant's antioxidant enzyme defence, particularly APX and GR, and reduced the amount of phenols and flavonoids. This resulted in increased ROS production and enhanced artemisinin content by 34.40% in DS plants treated with 200 mg•L-1 COS, compared to control plants.

Conclusion: These findings underscore the critical role of ROS in artemisinin biosynthesis and suggest that COS treatment may boost artemisinin yield in crop production, even under drought conditions.

Keywords: Artemisia annua; artemisinin; bioactive metabolites; chitosan oligosaccharide; drought; elicitation; stress.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Leaf water potential (A) and relative water content (B) in well-watered plants (WW) and drought-stressed plants (DS) treated with 0, 50, 100 and 200 mg·L-1 of COS. Different letters indicate significant differences according to the Tukey HSD test after two-way ANOVA, p< 0.05. Represented values are the mean ± SE.
Figure 2
Figure 2
(A) Scatter plot between digital biomass at the end of the experiment (DB_d9) and dry weight (DW) at the end of the experiment. (B) Dry weight at the end of the experiment in well-watered plants (WW) and drought-stressed plants (DS) treated with 0, 50, 100 and 200 mg·L-1 of COS. Different letters indicate significant differences according to the Kruskal-Wallis test, p< 0.05. Represented values are the mean ± SE.
Figure 3
Figure 3
Relative growth rate (A) calculated with digital biomass in well-watered plants (WW) and drought-stressed plants (DS) treated with 0, 50, 100 and 200 mg·L-1 of COS. Different letters indicate significant differences according to the Tukey HSD test after two-way ANOVA, p< 0.05. Represented values are the mean ± SE. RGB pictures of top camara (B) and side camara (C) used to calculate the digital biomass in well-watered plants (WW) and drought-stressed plants (DS) treated with 0, 50, 100 and 200 mg·L-1 of COS 2 and 9 days after the start of the experiment. Representative pictures of each experimental group were selected to (B) and (C).
Figure 4
Figure 4
Content of saturated fatty acids (A), polyunsaturated fatty acids (B), unsaturated fatty acids (C) and UFA/SFA ratio (D) in well-watered plants (WW) and drought-stressed plants (DS) treated with 0, 50, 100 and 200 mg·L-1 of COS. Different letters indicate significant differences according to the Tukey HSD test after two-way ANOVA, p< 0.05. Represented values are the mean ± SE.
Figure 5
Figure 5
Hydrogen peroxide content in well-watered plants (WW) and drought-stressed plants (DS) treated with 0, 50, 100 and 200 mg·L-1 of COS. Different letters indicate significant differences according to the Kruskal-Wallis test. p< 0.05. Represented values are the mean ± SE.
Figure 6
Figure 6
Activity of catalase (A), superoxide dismutase (B), ascorbate peroxidase (C) and glutathione reductase (D) in well-watered plants (WW) and drought-stressed plants (DS) treated with 0, 50, 100 and 200 mg·L-1 of COS. Different letters indicate significant differences according to the Tukey HSD test after two-way ANOVA, p< 0.05. Represented values are the mean ± SE.
Figure 7
Figure 7
Total phenolic content (A) and flavonoid content (B) in well-watered plants (WW) and drought-stressed plants (DS) treated with 0, 50, 100 and 200 mg·L-1 of COS. Different letters indicate significant differences according to the Tukey HSD test after two-way ANOVA in total phenolic content and to the Kruskal-Wallis test in flavonoid content, p< 0.05. Represented values are the mean ± SE.
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References

    1. Aebi H. (1984). Catalase in vitro . Methods Enzymol. 105, 121–126. doi: 10.1016/S0076-6879(84)05016-3 - DOI - PubMed
    1. Afzal S., Chaudhary N., Singh N. K. (2021). “Role of soluble sugars in metabolism and sensing under abiotic stress,” in Plant growth regulators: signalling under stress conditions (Switzerland: Springer International Publishing; ), 305–334. doi: 10.1007/978-3-030-61153-8_14 - DOI
    1. Agathokleous E., Kitao M., Komatsu M., Tamai Y., Harayama H., Koike T. (2022). Single and combined effects of fertilization, ectomycorrhizal inoculation, and drought on container-grown Japanese larch seedlings. J. For. Res. 1, 1–18. doi: 10.1007/S11676-022-01565-3 - DOI
    1. Ahluwalia O., Singh P. C., Bhatia R. (2021). A review on drought stress in plants: implications, mitigation and the role of plant growth promoting rhizobacteria. Resour. Environ. Sustain. 5, 100032. doi: 10.1016/j.resenv.2021.100032 - DOI
    1. Ahmad B., Khan M. M. A., Jahan A., Shabbir A., Jaleel H. (2020). Increased production of valuable secondary products in plants by leaf applied radiation-processed polysaccharides. Int. J. Biol. Macromol. 164, 286–294. doi: 10.1016/J.IJBIOMAC.2020.07.121 - DOI - PubMed