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

Abstract

Haematococcus pluvialis accumulates a large amount of astaxanthin under various stresses, e.g., blue light and salicylic acid (SA). However, the metabolic response of H. pluvialis to blue light and SA is still unclear. We investigate the effects of blue light and SA on the metabolic response in H. pluvialis using both transcriptomic and proteomic sequencing analyses. The largest numbers of differentially expressed proteins (DEPs; 324) and differentially expressed genes (DEGs; 13,555) were identified on day 2 and day 7 of the treatment with blue light irradiation (150 μmol photons m−2s−1), respectively. With the addition of SA (2.5 mg/L), a total of 63 DEPs and 11,638 DEGs were revealed on day 2 and day 7, respectively. We further analyzed the molecular response in five metabolic pathways related to astaxanthin synthesis, including the astaxanthin synthesis pathway, the fatty acid synthesis pathway, the heme synthesis pathway, the reactive oxygen species (ROS) clearance pathway, and the cell wall biosynthesis pathway. Results show that blue light causes a significant down-regulation of the expression of key genes involved in astaxanthin synthesis and significantly increases the expression of heme oxygenase, which shows decreased expression by the treatment with SA. Our study provides novel insights into the production of astaxanthin by H. pluvialis treated with blue light and SA.

Transcriptome Analysis of the Accumulation of Astaxanthin in Haematococcus pluvialis Treated with White and Blue Lights as well as Salicylic Acid

“…The high-throughput transcriptome sequencing analysis was performed on the 21 samples of seven groups of H . pluvialis treated with blue light, white light, and blue light with SA for 0, 2, and 7 days [ 25 ]. The results of assembly based on Trinity showed that a total of 256,961 transcripts and 109,443 unigenes were obtained ranging from 201 bp to 13,626 bp in length with the medians of 588 bp and 429 bp, the GC contents of 55.92% and 53.09%, and the N50 values of 1392 bp and 1193 bp, respectively.…”

Candida glycerinogenes-Promoted α-Pinene and Squalene Co-production Strategy Based on α-Pinene Stress

“…For example, astaxanthin is an unsaturated triterpene with strong antioxidant activity. The results of several studies have shown that Haematococcus pluvialis can increase its antioxidant capacity by accumulating astaxanthin under stress. , Xuya Yu et al . demonstrated that astaxanthin biosynthesis is controlled at the transcriptional level by the amount of intracellular ROS.…”

“…The results of several studies have shown that Haematococcus pluvialis can increase its antioxidant capacity by accumulating astaxanthin under stress. 17,18 Xuya Yu et al 19 demonstrated that astaxanthin biosynthesis is controlled at the transcriptional level by the amount of intracellular ROS. Squalene is a straightchain unsaturated triterpene compound containing 30 carbon atoms, 20 with a unique structural configuration that makes it an effective antioxidant, 21,22 facilitating rapid rejuvenation of damaged cells with improved cell healing capacity.…”