Tomato (Solanum lycopersicum) Homologs of TRIPTYCHON (SlTRY) and GLABRA3 (SlGL3) are involved in anthocyanin accumulation

Abstract

In Arabidopsis thaliana the CPC-like MYB transcription factors [CAPRICE (CPC), TRIPTYCHON (TRY), ENHANCER OF TRY AND CPC 1, 2, 3/CPC-LIKE MYB 3 (ETC1, ETC2, ETC3/CPL3), TRICHOMELESS 1, 2/CPC-LIKE MYB 4 (TCL1, TCL2/CPL4)] and the bHLH transcription factors [GLABRA3 (GL3) and ENHANCER OF GLABRA 3 (EGL3)] are central regulators of trichome initiation and root-hair differentiation. By transforming the tomato orthologous genes SlTRY (TRY) and SlGL3 (GL3) into Arabidopsis, we demonstrated that SlTRY inhibited trichome initiation and enhanced root-hair differentiation. These results suggest that tomato and Arabidopsis partially use similar transcription factors for epidermal cell differentiation, and that a CPC-like R3 MYB may be a key common regulator of plant trichome and root-hair development. CPC and GL3 are also known to be involved in anthocyanin biosynthesis. Here, we show that anthocyanin accumulation was repressed in the CPC::SlTRY and GL3::SlGL3 transgenic plants, suggesting that SlTRY and SlGL3 can influence anthocyanin pigment synthesis.

Arabidopsis CAPRICE (MYB) and GLABRA3 (bHLH) Control Tomato (Solanum lycopersicum) Anthocyanin Biosynthesis

“…Phylogenic analysis suggested that SlTRY and CPC originated from a single common ancestor [33] . SlTRY was shown to function quite similarly to the Arabidopsis CPC , including in the formation of ectopic root-hairs, in the induction of a no-trichome phenotype and in its action as a repressor of anthocyanin accumulation in Arabidopsis [34] . In summary, SlTRY functions in a similar way as CPC for the epidermal cell differentiation and the anthocyanin accumulation in Arabidopsis.…”

“…We concluded that tomato and Arabidopsis use similar transcription factors for root-hair and trichome cell differentiation and that the SlTRY -like R3 MYB may be a key common regulator of plant root-hair and trichome development [33] . In prior work, we also analyzed the anthocyanin content of SlTRY and SlGL3 transgenic Arabidopsis [34] . We showed that anthocyanin accumulation was repressed in the CPC::SlTRY and GL3::SlGL3 transgenic Arabidopsis plants, suggesting that the tomato genes of SlTRY and SlGL3 are involved in anthocyanin biosynthesis [34] .…”

“…In prior work, we also analyzed the anthocyanin content of SlTRY and SlGL3 transgenic Arabidopsis [34] . We showed that anthocyanin accumulation was repressed in the CPC::SlTRY and GL3::SlGL3 transgenic Arabidopsis plants, suggesting that the tomato genes of SlTRY and SlGL3 are involved in anthocyanin biosynthesis [34] .…”

A high-density genetic map developed by specific-locus amplified fragment (SLAF) sequencing and identification of a locus controlling anthocyanin pigmentation in stalk of Zicaitai (Brassica rapa L. ssp. chinensis var. purpurea)

“…Another bHLH TF (PIF3), directly binds with the promoters of genes involved in the biosynthesis of anthocyanin and act as a positive component in PHYA-mediated anthocyanin biosynthesis [50]. In tomato, bHLH TF gene SlGL3 is also not participating in the putative MBW protein complex in tomato as is the case in Arabidopsis [51]. In maize, several bHLH TFs were identified to induce tissue-specific anthocyanin biosynthesis, such as Lc, R, B, Sn and Hopi genes [52].…”

Overexpressing CAPRICE and GLABRA3 did not change the anthocyanin content of tomato (solanum lycopersicum) fruit peel

“…16 SlTRY had similar functions to CPC including root-hair induction, inhibition of trichome formation and anthocyanin accumulation in Arabidopsis. 16,17 On the other hand, SlGL3 did not show any observable GL3-like functions in Arabidopsis. 16,17 To evaluate evolutionary relationships among anthocyanin synthesis-related transcription factors, we performed phylogenetic analyses (Fig.…”