Investigating the effects of phytohormones on growth and beta-carotene production in a naturally isolates stain of Dunaliella salina

Abstract

The algae of the genus Dunaliella especially D. salina is among the microalgae most studied for mass culture. This alga is the richest algal source of glycerol and β-carotene, which is grown as a food source in aquaculture. In this study the effect of growth regulators (kinetin, gibberellic acid, indole-3-acetic acid, 6γ, γ-dimethylallyl aminopurine, salicylic acid and benzyl aminopurine) on the growth and β-carotene production in D. salina (MCCS 001) was investigated. Results pointed out that the β-carotene content and cell growth of D. salina could achieve the highest rates when kinetin and indole-3-acetic acid were used at 1 µM. Besides, it was shown that almost all of plant hormones has a positive effect on cell growth and β-carotene production in the microalga D. salina.

Enhanced β-carotene and Biomass Production by Induced Mixotrophy in Dunaliella salina across a Combined Strategy of Glycerol, Salinity, and Light

“…The effect of high intensity light has been related with the transcriptional activation of carotenogenic genes in response to stimulation by phytohormones [55]. Our results, in accordance with recent reports on high growth rates and β-carotene content in D. salina MCCS-001, are associated with the effect of indole-3-acetic acid [56] that could be derived from exogenous glycerol [57], which may support our results in cellular performance.…”

The Use of Microalgae and Cyanobacteria in the Improvement of Agricultural Practices: A Review on Their Biofertilising, Biostimulating and Biopesticide Roles

“…In higher plants, auxins, especially indole-3-acetic acid, are responsible for the regulation of growth and development [11]. In microalgae, these molecules also act as growth regulators, as auxins from C. vulgaris, D. salina, Nannochloropsis oceanica, Scenedesmus obliquus and Scenedesmus quadricauda have promoted an increase in cell size and chlorophyll and protein contents, as well as cell division, which resulted in higher biomass productivities [61][62][63][64][65]. Abscisic acid is commonly associated with the cellular response to environmental stress factors, such as high salinity levels, drought and nutrients scarcity [10,11].…”

“…In microalgae and cyanobacteria, this molecule is quite effective in the control of cells' response to salt, osmotic, oxidative, drought and nutrients' stresses [67,68]. Common responses induced by the activation of the abscisic acid pathway include the production of carotenoids, which typically act as protecting agents against oxidative stress [62]. Regarding cytokinins, these molecules mediate several processes in higher plants, namely cell division, growth, biogenesis, chloroplasts differentiation, regulation of seed dormancy, among others [10].…”

“…For example, cytokinins from Acutodesmus obliquus, C. vulgaris and Gracilaria caudata have been associated with increased pigments' contents in these organisms, which resulted in higher photosynthetic rates and, hence, higher biomass productivities [70][71][72]. Additionally, a cytokinin produced by D. salina, kinetin, induced the accumulation of the photo-protective pigment beta-carotene in this microalga [62]. Ethylene is known for its multiple responses in plants, which range from the regulation of plants' growth and ageing, to the improvement of plants' tolerance to both biotic and abiotic stress factors [10].…”

Phytohormones and Effects on Growth and Metabolites of Microalgae: A Review

“…There are more examples of CK promoting the accumulation of photosynthetic pigments in C. vulgaris [37] and D. salina [31], leading to a boost in growth. However, there is contradictory evidence that synthetic cytokinins do not affect chlorophyll content but improve the growth of Chlamydomonas reinhardtii [80], while CKs have a stimulatory effect on pigments of Gracilaria caudata but do not affect growth [38].…”