Identification of QTLs affecting scopolin and scopoletin biosynthesis in Arabidopsis thaliana

Abstract

BackgroundScopoletin and its glucoside scopolin are important secondary metabolites synthesized in plants as a defense mechanism against various environmental stresses. They belong to coumarins, a class of phytochemicals with significant biological activities that is widely used in medical application and cosmetics industry. Although numerous studies showed that a variety of coumarins occurs naturally in several plant species, the details of coumarins biosynthesis and its regulation is not well understood. It was shown previously that coumarins (predominantly scopolin and scopoletin) occur in Arabidopsis thaliana (Arabidopsis) roots, but until now nothing is known about natural variation of their accumulation in this model plant. Therefore, the genetic architecture of coumarins biosynthesis in Arabidopsis has not been studied before.ResultsHere, the variation in scopolin and scopoletin content was assessed by comparing seven Arabidopsis accessions. Subsequently, a quantitative trait locus (QTL) mapping was performed with an Advanced Intercross Recombinant Inbred Lines (AI-RILs) mapping population EstC (Est-1 × Col). In order to reveal the genetic basis of both scopolin and scopoletin biosynthesis, two sets of methanol extracts were made from Arabidopsis roots and one set was additionally subjected to enzymatic hydrolysis prior to quantification done by high-performance liquid chromatography (HPLC). We identified one QTL for scopolin and five QTLs for scopoletin accumulation. The identified QTLs explained 13.86% and 37.60% of the observed phenotypic variation in scopolin and scopoletin content, respectively. In silico analysis of genes located in the associated QTL intervals identified a number of possible candidate genes involved in coumarins biosynthesis.ConclusionsTogether, our results demonstrate for the first time that Arabidopsis is an excellent model for studying the genetic and molecular basis of natural variation in coumarins biosynthesis in plants. It additionally provides a basis for fine mapping and cloning of the genes involved in scopolin and scopoletin biosynthesis. Importantly, we have identified new loci for this biosynthetic process.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-014-0280-9) contains supplementary material, which is available to authorized users.

SG2-Type R2R3-MYB Transcription Factor MYB15 Controls Defense-Induced Lignification and Basal Immunity in Arabidopsis

“…A recent quantitative trait loci mapping study for scopoletin biosynthesis identified monolignol pathway genes HCT and COMT as possible candidate regulators of scopoletin biosynthesis (Siwinska et al, 2014), lending further support to the existence of a complex regulatory relationship between the monolignol, HCAE, and scopoletin biosynthetic pathways.…”

“…MYB15 is also necessary for basal expression of scopoletin, a preformed defense mechanism that contributes significantly to disease resistance against a biotrophic pathogen. Interestingly, the MYB15 gene (At3g23250) is close to the map position of the highest LOD-scoring quantitative trait loci (SCT3) for scopoletin accumulation in Arabidopsis (Siwinska et al, 2014). Scopoletin is also a preformed defense mechanism in tobacco, contributing significantly to disease resistance against the necrotrophic pathogen Alternaria alternata (Sun et al, 2014).…”

Arabidopsis thalianaG2‐LIKE FLAVONOID REGULATOR and BRASSINOSTEROID ENHANCED EXPRESSION1 are low‐temperature regulators of flavonoid accumulation

“…It has been suggested that these compounds, acting as either UV/visible light screens or as antioxidants, may protect photosynthetic tissue against low‐temperature‐induced photoinhibition (Steyn et al ., ; Neill & Gould, ; Agati & Tattini, ). Scopolin is a coumarin glycoside found primarily in A. thaliana roots, providing antimicrobial and antioxidant activities, and it is also produced as a defense agent against pathogen attack (Kai et al ., ; Siwinska et al ., ). Here, we show that low temperature is another factor that induces the accumulation of scopolin in the leaves of A. thaliana .…”

10th International Conference, Plant Functioning Under Environmental Stress, September 16-19, 2015, Cracow, Poland

“…In the last years, coumarins, namely scopoletin, scopolin, skimmine and esculin, were identi ed in roots and shoots of Arabidopsis thaliana reference ecotype Columbia (Bednarek 2005;Kai et al 2006). Recently, it was shown by our group that a signi cant natural variation in the accumulation of scopoletin and scopolin is present among seven A. thaliana ecotypes (Siwinska et al 2014). The research presented here, aimed at broad pro ling of coumarins in the tissues of 27 ecotypes originating from different geographical locations.…”