Table 1.

The effects of chitosan on medicinal and aromatic plants.

Plant	Scientific Name	Plant Family	Key Point	References
Basil	Ocimum basilicum; Ocimum ciliatum	Lamiaceae	Various amounts of chitosan had considerable impacts on the antioxidant activity and total phenol content of the extracts of two species.	[107,108]
			Chitosan could be a promising material used to reduce the adverse impacts of water stress on the growth factors of basil seedlings.	[108]
Bitter melon	Momordica charantia L.	Cucurbitaceae	An application of chitosan and their conjugated forms as nanoparticles (Se-CS NPs) improved the biochemical and morphophysiological characteristics of bitter melon plants under moderate and severe salinity stress condition.	[109]
			Exogenous utilization of Se-CS NPs leads to the expression of multiple defense- and secondary metabolism-related transcripts in bitter melon plants.	[109]
Dendrobium orchids	Dendrobium	Orchidaceae	Chitosan showed the ability to improve floral production of the Dendrobium.	[110]
			It also stimulated the number of vascular bundles in both young and old leaves.	[110]
Dragonhead	Dracocephalum kotschyi Boiss	Lamiaceae	It was an effectual elicitor for increasing rosmarinic acid and quercetin content.	[111]
			Chitosan increased the content of apigenin noticeably.	[111]
			A chitosan spray had a significant influence on the principle essential oil components, such as p-cymene and thymol.	[112]
Fenugreek	Trigonella foenum-graecum L.	Leguminosae	The activity of nitrate reductase and the contents of photosynthetic pigments and carbonic anhydrase enzymes were significantly increased after an application of Co-60 gamma-irradiated chitosan.	[113]
			Co-60 gamma-irradiated chitosan significantly boosted the total alkaloid content, seed yield, and trigonelline constituent.	[113]
Galega	Galega officinalis L.	Leguminosae	An application of chitosan had a more optimal impact on the morphological characteristics.	[114]
German chamomile	Matricaria recutita L.	Asteraceae	Its foliar spray in the flowering stage increased the chamomile flower number and weight per plant.	[115]
			Its usage at the rate of 40 ppm is suggested for German chamomile cultivation.	[115]
Ginger	Zingiber officinale L.	Zingiberaceae	Its application induced the HR marker gene HSR203J in ginger and inhibited the expression of cell death markers AIF2, HIN1, and AIF1.	[116]
			Chitosan has the potential to prime standing ginger plants against soft rot disease and facilitate appropriate sustainable management of ginger soft rot (Pythium myriotylum).	[116]
Hyssop	Hyssopus officinalis L.	Lamiaceae	The results show that spraying chitosan at 2.5 g/L significantly increased the measurements of the canopy diameter, inflorescence height, plant height, numbers of auxiliary and flowering branches, dry herbal weight, and the components of photosynthesis pigments under various levels of irrigation frequencies.	[117]
			The maximum values of the volatile oil yield were related to the chitosan-spraying in a reduced irrigation condition.	[117]
			Chitosan had noticeable effects on the percentage of (cis- and trans-) pinocamphone, as the predominant components of hyssop volatile oil, under a reduced irrigation condition.	[117]
Indian borage (Indian mint)	Coleus aromaticus Benth (L.)	Lamiaceae	A mixture of Chitosan and cytokinin showed a positive impact on multiple shoot induction than cytokinin alone.	[118]
			Its application also increased the percentage of alkaloids, flavonoids, terpenoids, saponins, tannins, and total phenolic content.	[118]
Lavender-cotton	Santolina chamaecyparissus L.	Asteraceae	Its application improved antifungal capacities and increased some physical characteristics.	[119]
Lemon balm	Melissa officinalis L.	Lamiaceae	It increased plant regeneration in a callus culture of a medicinal herb.	[120]
			Its consumption consists of the trigger of defense-related enzymes; stimulated expression of rosmarinic acid synthase (RAS) genes and tyrosine aminotransferase (TAT); and stimulation of methyl jasmonate biosynthesis.	[121]
Milk thistle	Silybum marianum (L.) Gaertn.	Asteraceae	Significant reduction of the negative impact of salinity and increased plant growth and improved physiological characteristics occurred after its application.	[83]
			Its usage at 0.01% increased the chlorophyll and total chlorophyll content.	[83]
			Its application promoted the enzymatic activity and reduced H2O2 components in the leaves.	[83]
			Chitosan may protect plants from salt stress damage by regulation of the intracellular ion component and through increasing the capability of antioxidant enzyme activities.	[83]
Moringa	Moringa oleifera L.	Moringaceae	Chitosan improved the plant growth parameters: root length, root fresh weight, shoot length, shoot fresh weight, shoot dry weight, root dry weight, and contents of chlorophyll-b and chlorophyll-a.	[122]
Peppermint	Mentha piperita L.	Lamiaceae	Under drought stress, the usage of chitosan-coated iron oxide nanoparticles (Fe-CTs NPS) increased essential oils production in the mint plant.	[123]
			Under foliar spray of chitosan, the maximum constituents of the essential oil yield, menthol, and the balance of menthol/menthone of the essential oil from peppermint were achieved from the peppermint plants.	[92]
Roselle	Hibiscus sabdariffa L.	Malvaceae	Chitosan nanofiber (CNF) treatments affected the plant growth regulators’ impact on most of the traits evaluated.	[124]
			It could be applied for enhancement of the number of calyxes, plant height, total chlorophyll, β-carotene, antioxidant activity, and flavonoids.	[124]
Savory	Satureja hortensis L.	Lamiaceae	Under severe water stress, its application improved the total soluble sugar, antioxidant activity, total phenolic and proline contents, and essential oil content of the seedlings.	[125]
			Under water stress conditions, it may have positive influences on the essential oil quality and quantity, osmotic adjustment, antioxidant activity, and growth of summer savory.	[125]
Spearmint	Mentha spicata L.	Lamiaceae	Chitosan–melatonin nanoparticles could be used as an innovative protective agent to reduce the impact of salinity in spearmint plants.	[126]
St. John’s wort	Hypericum perforatum L.	Clusiaceae	It showed a significant rise in xanthone production and a simultaneous decline in flavonoid production.	[127]
			Chitosan also led to the production of 1,7-dihydroxyxanthone (euxanthone).	[127]
Sweet marjoram	Majorana hortensis Moench	Lamiaceae	Its application improved the marjoram biomass and secondary metabolites’ assimilation.	[128]
Tashenehdari	Scrophularia striata Boiss.	Scrophulariaceae	The increase in amino acid content and phenylalanine ammonia-lyase (PAL) activity was related to rises in the phenolic components after application of chitosan treatments.	[129]
			Chitosan, by up-regulating the PAL gene, increases the production of the phenylpropanoid content.	[129]
Thyme	Thymus daenensis Celak	Lamiaceae	Under the mild stress, the maximum essential oil yield was related to the utilization of 400 μL−1 chitosan.	[130]
Mediterranean thyme	Thymbra spicata L.	Lamiaceae	The carvacrol level in the essential oil escalated in the plants after application of chitosan.	[131]
			The spray of chitosan could reduce the harmful impacts of water shortage on the oil yield and the carvacrol percentage.	[131]
Russian sage	Salvia abrotanoides (Kar.) Sytsma	Lamiaceae	A chitosan foliar application can increase drought tolerance.	[132]
			The leaves showed significant antioxidant enzyme activity under drought stress using chitosan nanoparticles.	[132]
Turmeric	Curcuma longa L.	Zingiberaceae	Its application improved the production of curcumin.	[133]
			The chitosan could boost the activity or protease inhibitor in rhizomes and leaves.	[133]
Wild mint	Mentha arvensis L.	Lamiaceae	The 0.125% content of chitosan provides a higher accumulation of roots, shoots, and total dry weight. The maximum menthol content is obtained after application of 0.06% chitosan.	[134]
Winged-fruited marigold	Calendula tripterocarpa Rupr.	Asteraceae	The chitosan application also increased the growth parameters, carotenoids, and levels of chlorophyll a, b under both Ni stress and normal conditions.	[135]
			Chitosan decreased the level of malondialdehyde and the activities of catalase (CAT) and superoxide dismutase (SOD) in the shoot and roots under Ni stress.	[135]