Overexpression of a Novel Cytochrome P450 Promotes Flavonoid Biosynthesis and Osmotic Stress Tolerance in Transgenic Arabidopsis

Abstract

Flavonoids are mainly associated with growth, development, and responses to diverse abiotic stresses in plants. A growing amount of data have demonstrated the biosynthesis of flavonoids through multienzyme complexes of which the membrane-bounded cytochrome P450 supergene family shares a crucial part. However, the explicit regulation mechanism of Cytochrome P450s related to flavonoid biosynthesis largely remains elusive. In the present study, we reported the identification of a stress-tolerant flavonoid biosynthetic CtCYP82G24 gene from Carthamus tinctorius. The transient transformation of CtCYP82G24 determined the subcellular localization to the cytosol. Heterologously expressed CtCYP82G24 was effective to catalyze the substrate-specific conversion, promoting the de novo biosynthesis of flavonoids in vitro. Furthermore, a qRT-PCR assay and the accumulation of metabolites demonstrated that the expression of CtCYP82G24 was effectively induced by Polyethylene glycol stress in transgenic Arabidopsis. In addition, the overexpression of CtCYP82G24 could also trigger expression levels of several other flavonoid biosynthetic genes in transgenic plants. Taken together, our findings suggest that CtCYP82G24 overexpression plays a decisive regulatory role in PEG-induced osmotic stress tolerance and alleviates flavonoid accumulation in transgenic Arabidopsis.

Unprecedented evolution and transcriptional reprogramming of CYP81E subfamily in Carthamus tinctorius during flavonoid biosynthesis

“…These ndings were effectively supported by our recent studies on CtCYP82G24, [32], which outlined the core concept of the correlation analysis between quantitative gene expression trend and metabolite accumulation pattern under abiotic stress encounter in transgenic Arabidopsis. In addition to this, we also reported the upregulation of CtCYP82C1 transcription under arti cial hormonal and abiotic stress exposure [51].…”

“…Based on our previous study on a CtCYP82G24, [32], we aimed to investigate the correlation between the quantitative expression trend of CtCYP81E8 gene and metabolite accumulation at different owering stages of sa ower. As described in (Fig.…”

Transcriptome Dynamics during Black and White Sesame (Sesamum indicum L.) Seed Development and Identification of Candidate Genes Associated with Black Pigmentation

“…The two varieties were shown at the experimental station of the Oil Crops Research Institute (OCRI) under identical growth conditions from May to September 2019 in Wuhan, Hubei Province, China, at N 30.57 • , E 114.30 • , altitude 27 m. Flowers were labeled every three days post-anthesis (DPA). At 5,8,11,14,17,20,23,26, and 30 DPA, capsules for each variety were sampled from 10 plants ( Figure 2), and seeds were separated from the capsules on ice. Different plant seeds were therefore mixed equally and represented samples at 5,8,11,14,17,20,23,26, and 30 DPA.…”

“…The expression profiles of the 17 candidate genes were validated with qRT-PCR, referring to Wang et al [38] using LightCycler®480II Real-Time PCR Detection System (Roche Diagnostics, Rotkreuz, Switzerland). Five stages (5,11,17,23, and 30 DPA) seed samples were run in triplicate on the same plate with a negative control that lacked cDNA. The gene actin7 of sesame was used as a positive control.…”

“…Additionally, it has been used to detect candidate genes that shaped oil content variation in sesame [33]. In this study, we investigated the transcriptome during the seed development stages at the 5,8,11,14,17,20,23,26, and 30 days post-anthesis (DPA) of two sesame varieties different in seed coat color "Zhongfengzhi No.1" (white seed) and "Zhongzhi No.33" (black seed). Differentially expressed genes (DEGs) and some candidate genes for sesame seed coat color were identified.…”