PbLAC4-like, activated by PbMYB26, related to the degradation of anthocyanin during color fading in pear

Abstract

Background Decrease in anthocyanin content results in the loss of red color in leaves, petals and receptacles during development. The content of anthocyanin was affected by the biosynthesis and degradation of anthocyanin. Compared with the known detailed mechanism of anthocyanin biosynthesis, the degradation mechanism is not fully investigated. It is vital to study the degradation mechanism of anthocyanin in pear for promoting the accumulation of anthocyanin and inhibiting the red fading in pear. Results Here, we reported that laccase encoded by PbLAC4-like was associated with anthocyanin degradation in pear. The expression pattern of PbLAC4-like was negatively correlated with the content of anthocyanin during the color fading process of pear leaves, petals and receptacles. Phylogenetic analysis and sequence alignment revealed that PbLAC4-like played a vital role in anthocyanin degradation. Thus, the degradation of anthocyanin induced by PbLAC4-like was further verified by transient assays and prokaryotic expression. More than 80% of anthocyanin compounds were degraded by transiently over-expressed PbLAC4-like in pear fruitlet peel. The activity of crude enzyme to degrade anthocyanin in leaves at different stages was basically consistent with the expression of PbLAC4-like. The anthocyanin degradation ability of prokaryotic induced PbLAC4-like protein was also verified by enzyme activity assay. Besides, we also identified PbMYB26 as a positive regulator of PbLAC4-like. Yeast one-hybrid and dual luciferase assay results showed that PbMYB26 activated PbLAC4-like expression by directly binding to the PbLAC4-like promoter. Conclusions Taken together, the PbLAC4-like activated by PbMYB26, was involved in the degradation of anthocyanin, resulting in the redness fading in different pear tissues.

RsGSTF12 Contributes to Anthocyanin Sequestration in Radish (Raphanus sativus L.)

“…Our results showed that the mutant phenotypes of the tt19 mutant could be partly restored by the expression of RsGSTF12. Like the functions of MdGSTF6 and GhGSTF12, RsGSTF12 could complement anthocyanin pigmentation in vegetative tissues, despite no color change evident in the seed coat (Figure 6) (Jiang et al, 2019;Zhao et al, 2021). Overall, RsGSTF12 is involved in the process of anthocyanin accumulation.…”

“…The transient expression system is a direct and important methodological tool used to understand the functions of proteins and is now widely used in various plants, such as apple, pear, and strawberry ( Jiang et al, 2019 ; Castillejo et al, 2020 ; Zhao et al, 2021 ). In this study, when RsGSTF12 and GmMYB75 (a positive anthocyanin regulator in soybean) were co-transferred transiently into radish leaves, the leaves appeared much more anthocyanin compared with either of them injected ( Figure 5A ).…”

Pigment Diversity in Leaves of Caladium × hortulanum Birdsey and Transcriptomic and Metabolic Comparisons between Red and White Leaves

“…Interestingly, some transcription factors can even regulate the appearance of the white phenotype in plant tissues. For example, PbMYB26 can degrade anthocyanin in the petals, leaves, and pedicels of pear by activating the expression of PbLAC4 , and even produce a white phenotype [ 41 ]. In tobacco, CRISPR/Cas9-induced mutation in the RcMYB3 gene of Rubus chingii Hu.…”

Multi-Omics Analysis Reveals That Anthocyanin Degradation and Phytohormone Changes Regulate Red Color Fading in Rapeseed (Brassica napus L.) Petals

“…However, the modulation of anthocyanin degradation has not been fully investigated. In pear, PbLAC4-like gene functions to regulate anthocyanin degradation through activation of PbMYB26 during fading [ 65 ]. A study of Malus hupehensis petals fading from red to white found significantly higher expression levels of PAL , CHS , CHI , DFR , FLS , ANS , UFGT , MYB10 , and MYB12 at early development stages than later stages.…”

“…For example, there is only single cell layer in Papaver somniferum L., while there are several cell Similarly, co-expression analysis was conducted between phytohormone content and corresponding genes based on the correlation coefficient and significance level. The results show that JA, ACC, ABA, GA3, indol-3-acetic acid, indole-3-carboxaldehyde, isopentenyl adenosine, kinetin, melatonin, methyl indole-3-acetate, methyl jasmonate, SA, and transzeatin-riboside had 73, 104, 74, 4,39,65,63,61,29,63,35,118, and 69 pairs, respectively (Figure 9b).…”