Transcriptome profiling of anthocyanin-related genes reveals effects of light intensity on anthocyanin biosynthesis in red leaf lettuce

Abstract

Red leaf lettuce (Lactuca sativa L.) is popular due to its high anthocyanin content, but poor leaf coloring often occurs under low light intensity. In order to reveal the mechanisms of anthocyanins affected by light intensity, we compared the transcriptome of L. sativa L. var. capitata under light intensities of 40 and 100 μmol m−2 s−1. A total of 62,111 unigenes were de novo assembled with an N50 of 1,681 bp, and 48,435 unigenes were functionally annotated in public databases. A total of 3,899 differentially expressed genes (DEGs) were detected, of which 1,377 unigenes were up-regulated and 2,552 unigenes were down-regulated in the high light samples. By Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the DEGs were significantly enriched in 14 pathways. Using gene annotation and phylogenetic analysis, we identified seven anthocyanin structural genes, including CHS, CHI, F3H, F3′H, DFR, ANS, and 3GT, and two anthocyanin transport genes, GST and MATE. In terms of anthocyanin regulatory genes, five MYBs and one bHLH gene were identified. An HY5 gene was discovered, which may respond to light-signaling and regulate anthocyanin structural genes. These genes showed a log2FC of 2.7–9.0 under high irradiance, and were validated using quantitative real-time-PCR. In conclusion, our results indicated transcriptome variance in red leaf lettuce under low and high light intensity, and observed a anthocyanin biosynthesis and regulation pattern. The data should further help to unravel the molecular mechanisms of anthocyanins influenced by light intensity.

The Genetic Basis and Nutritional Benefits of Pigmented Rice Grain

“…The enhanced abundance of transcripts of chalcone synthetase, flavanone 3-hydroxylase, and anthocyanin synthetase seen in some black varieties implied a strong correlation between transcription and pigment content. Sun et al (2018) found that flavonoid pathway genes were regulated by ternary MYB-bHLH-WD40 transcriptional complexes Zhang et al, 2018). A microarray-based comparison of black and white rice identified nearly 1,300 differentially transcribed genes, of which 137 were predicted to encode transcription factors belonging to 1 of 10 different classes .…”

“…Anthocyanin production in pigmented grain appeared to be induced and fine-tuned by BBX14 in conjunction with the basic leucine zipper transcription factor HY5. Both irradiation at a high light intensity and the plant's sugar content can influence anthocyanin and proanthocyanin synthesis Ma et al, 2018;Zhang et al, 2018). Therefore it would be of value to search for linkages between photoreceptor and light signal transduction elements associated with anthocyanin/proanthocyanidin synthesis in pigmented rice (Teng et al, 2005).…”

BrmiR828 Targets BrPAP1, BrMYB82, and BrTAS4 Involved in the Light Induced Anthocyanin Biosynthetic Pathway in Brassica rapa

“…Light signaling components such as PIF3, CYR1, UVR8, and HY5 have been demonstrated to be key light signal transduction factors involved in anthocyanin biosynthesis under different light conditions [11][12][13][14]. Blue and UV-A light have also been reported to induce the expression of genes involved in anthocyanin biosynthesis in Brassica rapa [15,16], Litchi chinensis [17], Lactuca sativa [18], Arabidopsis [12], and Pyrus [19]. miRNAs negatively regulate the expression of genes involved in light-regulated processes [20,21].…”

Peer Review #3 of "Comparison of prediction power of three multivariate calibrations for estimation of leaf anthocyanin content with visible spectroscopy in Prunus cerasifera (v0.1)"

“…Manuscript to be reviewed He, 2008;Wu et al, 2011;Zhang et al, 2018). Partial least-squares regression can reduce data noise and computation time, with only minor loss of the information contained in the original variables.…”

“…These compounds also play a photo-protective role (Liakopoulos et al, 2006), and act as optical barriers (Close & Beadle, 2003;. A number of environmental stresses, such as strong light, low temperature, UV-B irradiation, wounding, drought, bacterial and fungal infections, deficiencies in nitrogen, phosphorus and potassium, and certain herbicides and pollutants can result in the significant accumulation of anthocyanins (Saure, 1990;Garriga et al, 2014;Zhang et al, 2018), which are thus often referred to as "stress pigments" (Chalker-Scott, 1999). In addition, anthocyanins accumulate transiently in juvenile and senescing leaves in many plant species under unfavorable conditions (Karageorgou & Manetas, 2006;Merzlyak et al, 2008;Zeliou, Manetas & Petropoulou, 2009;Garriga et al, 2014).…”