Comparative transcriptome analysis of Haematococcus pluvialis on astaxanthin biosynthesis in response to irradiation with red or blue LED wavelength

Abstract

The unicellular green microalga Haematococcus pluvialis has the highest content of the natural antioxidant, astaxanthin. Previously, it was determined that astaxanthin accumulation in H. pluvialis could be induced by blue-wavelength irradiation; however, the molecular mechanism remains unknown. The present study aimed to compare the transcriptome of H. pluvialis, with respect to astaxanthin biosynthesis, under the monochromatic red (660 nm) or blue (450 nm) light-emitting diode (LED) irradiation. Among a total of 165,372 transcripts, we identified 67,703 unigenes, of which 2245 and 171 were identified as differentially expressed genes (DEGs) in response to blue and red irradiation, respectively. Interestingly, expressional changes of blue light receptor cryptochromes were detected in response to blue and/or red LED irradiation in H. pluvialis, which may directly and indirectly regulate astaxanthin biosynthesis. In accordance with this observation, expression of the BKT and CHY genes, which are part of the downstream section of the astaxanthin biosynthetic pathway, was significantly upregulated by blue LED irradiation compared with their expression under control white irradiation. Contrastingly, they were downregulated by red LED irradiation. Our transcriptome study provided molecular insights that highlighted the different of responses of H. pluvialis to red and blue irradiation, especially for astaxanthin biosynthesis.

Cloning, expression, and characterization of a novel plant type cryptochrome gene from the green alga Haematococcus pluvialis

“…[30][31][32][33]. Moreover, previous studies have shown that under the same light intensity, blue light is more effective in inducing the accumulation of astaxanthin in H. pluvialis than white light, and the transcriptional expression of genes related to astaxanthin synthesis (psy, pds, crtR, cyp97a, cyp97c, bch, crtO and bkt) are significantly increased [28,34,35]. The accumulation of astaxanthin induced by blue light is closely related to the high expression of related genes at the transcriptional level.…”

“…High light is considered an effective stimulus to induce accumulation of astaxanthin in the economic green alga H. pluvialis [28,[32][33][34][35]. In order to test the expression of Hae-P-CRY under light stress, the timecourse transcriptional patterns in photoautotrophic H. pluvialis under different HL conditions were determined (Fig.…”

Wybrane aspekty biotechnologicznej produkcji karotenoidów

“…W porównawczej analizie transkryptomu H. pluvialis w odniesieniu do procesu biosyntezy astaksantyny w odpowiedzi na monochromatyczne czerwone (660 nm) oraz niebieskie (450 nm) światło emitowane przez diody LED wykazano, że promieniowanie to stanowi kolejny czynnik, który umożliwia zwiększenie mikrobiologicznej produkcji tego karotenoidu [28]. Transformacja genu desaturazy fitoenu (EC 1.3.99.31) w chloroplastach H. pluvialis pod kontrolą promotora psbA/UTR pozwoliła na zwiększenie akumulacji astaksantyny w komórkach o blisko 67 % [16].…”

“…Zasadnicze problemy w modyfikacji szlaku biosyntezy karotenoidów stanowią prekursory, które są zużywane do rozszerzenia istniejących ścieżek metabolicznych [13,28,47]. Kolejna kwestia to zapewnienie magazynowania w komórkach produktu, zwłaszcza jeśli jest on lipofilny tak jak karotenoidy.…”

Transcriptomic and Proteomic Characterizations of the Molecular Response to Blue Light and Salicylic Acid in Haematococcus pluvialis

“…Due to its less heat dissipation with long life-expectancy and small size, the lightemitting diode (LED) has become an important factor in the microalgal industry [9]. Blue, green, and red lights are important for the growth and development of microalgae [10]. For example, blue light increases the cell size of algae, lipid accumulation, and growing period in Chlamydomonas reinhardtii [11,12], while green light of high intensities could significantly promote photosynthesis [13], and red light increases growth rates in Dunaliella salina and Spirulina [14]; meanwhile, a red LED at a relatively low intensity enhances cell growth in H. pluvialis [15].…”