An LcMYB111-LcHY5 Module Differentially Activates an LcFLS Promoter in Different Litchi Cultivars

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Flavonol synthase (FLS) is the crucial enzyme of the flavonol biosynthetic pathways, and its expression is tightly regulated in plants. In our previous study, two alleles of LcFLS, LcFLS-A and LcFLS-B, have been identified in litchi, with extremely early-maturing (EEM) cultivars only harboring LcFLS-A, while middle-to-late-maturing (MLM) cultivars only harbor LcFLS-B. Here, we overexpressed both LcFLS alleles in tobacco, and transgenic tobacco produced lighter-pink flowers and showed increased flavonol levels while it decreased anthocyanin levels compared to WT. Two allelic promoters of LcFLS were identified, with EEM cultivars only harboring proLcFLS-A, while MLM cultivars only harbor proLcFLS-B. One positive and three negative R2R3-MYB transcription regulators of LcFLS expression were identified, among which only positive regulator LcMYB111 showed a consistent expression pattern with LcFLS, which both have higher expression in EEM than that of MLM cultivars. LcMYB111 were further confirmed to specifically activate proLcFLS-A with MYB-binding element (MBE) while being unable to activate proLcFLS-B with mutated MBE (MBEm). LcHY5 were also identified and can interact with LcMYB111 to promote LcFLS expression. Our study elucidates the function of LcFLS and its differential regulation in different litchi cultivars for the first time.
Funding Information
  • Natural Science Foundation of Guangdong Province, China (2020A1515010356, 2022B0202070003, 2023B01J2002, 2023KJ107, 2023TS-2-1, 2023A04J0797)
  • Key-Area Research and Development Program of Guangdong Province, China (2020A1515010356, 2022B0202070003, 2023B01J2002, 2023KJ107, 2023TS-2-1, 2023A04J0797)
  • Key Research and Development Program of Guangzhou City, China (2020A1515010356, 2022B0202070003, 2023B01J2002, 2023KJ107, 2023TS-2-1, 2023A04J0797)
  • Guangdong Litchi Industry Technology System (2020A1515010356, 2022B0202070003, 2023B01J2002, 2023KJ107, 2023TS-2-1, 2023A04J0797)
  • Special Fund for Rural Revitalization Strategy (2020A1515010356, 2022B0202070003, 2023B01J2002, 2023KJ107, 2023TS-2-1, 2023A04J0797)
  • Science and Technology Planning Project of Guangzhou Municipal Science and Technology Bureau (2020A1515010356, 2022B0202070003, 2023B01J2002, 2023KJ107, 2023TS-2-1, 2023A04J0797)

This publication has 62 references indexed in Scilit: