Molecular mechanism for jasmonate-induction of anthocyanin accumulation in Arabidopsis

Abstract

Anthocyanins are important plant pigments that fulfil many physiological and ecological functions. Anthocyanin biosynthesis is controlled by numerous regulatory factors at the transcriptional level. Jasmonates (JAs) has been shown to induce anthocyanin accumulation in several plant species, however, the molecular mechanism for JA-regulated anthocyanin accumulation remains unknown. In this study, genetic, molecular, and physiological approaches were used to reveal the molecular basis of JA-regulated pigmentation in Arabidopsis. It was found that the F-box protein COI1 was required for JA-specific induced expression of the 'late' anthocyanin biosynthetic genes DFR, LDOX, and UF3GT. It is further demonstrated that COI1 was essential for JA-induction of transcription factors PAP1, PAP2, and GL3. It is speculated that COI1 regulates the expression of the transcription factors, including PAP1, PAP2, and GL3, which mediates the 'late' anthocyanin biosynthetic genes DFR, LDOX, and UF3GT, thereby modulating JA-induced anthocyanin biosynthesis in Arabidopsis.

A bHLH-Type Transcription Factor, ABA-INDUCIBLE BHLH-TYPE TRANSCRIPTION FACTOR/JA-ASSOCIATED MYC2-LIKE1, Acts as a Repressor to Negatively Regulate Jasmonate Signaling inArabidopsis

“…Trichome formation, which is not affected in myc2 mutants (Yoshida et al, 2009), was reduced in ProJAM1:JAM1-SRDX plants (see Supplemental Figure 4 online). These phenotypes are probably due to the impaired JA responsiveness of JAM1 CRES-T plants because JA mediates anthocyanin biosynthesis and trichome formation (Shan et al, 2009;Yoshida et al, 2009;Qi et al, 2011).…”

Disruption of OPR7 and OPR8 Reveals the Versatile Functions of Jasmonic Acid in Maize Development and Defense

“…Because JA mutants have not been available, it is not surprising that JA has not been implicated in the regulation of anthocyanin biosynthesis in monocots. However, a number of studies have shown that JA induces anthocyanin accumulation in several dicotyledonous plants (Shan et al, 2009). JA-regulated pigmentation in Arabidopsis was shown to be dependent on JA signaling SCF-COI1 complex interacting with WD-repeat/bHLH/MYB complexes (Qi et al, 2011).…”

Sugar-Hormone Cross-Talk in Anthocyanin Biosynthesis

“…A recent finding that the photosynthetic electron transport (PET) chain, in addition to the well-characterized HY5-dependent signaling, plays an important role in light signaling pathways in green, vegetative leaf tissues (Das et al, 2011;Jeong et al, 2010) demonstrates the complexity of the cross-talk between various pathways. Sugar-induced anthocyanin biosynthesis is apparently modulated by the heterotrimeric M(L2)BW complexes that are under the regulation of hormones (Das et al, 2012;Jeong et al, 2010;Loreti et al, 2008;Shan et al, 2009), Fig. 1.…”