R2R3‐MYB transcription factor MdMYB23 is involved in the cold tolerance and proanthocyanidin accumulation in apple

Abstract

Cold stress severely affects plant growth and yield. C-repeat binding factors (CBFs) play important roles in the response to cold stress. In the present study, we identified an R2R3-MYB transcription factor (TF) MdMYB23 from apple (Malus × domestic) using transcriptome analyses, which was notably induced in response to cold stress. Transgenic apple calli and Arabidopsis with overexpression of MdMYB23 exhibited increased cold tolerance. Electrophoretic mobility shift assay (EMSA) and transient expression assays indicated that MdMYB23 directly bound to the promoters of MdCBF1 and MdCBF2 and activated their expression. MdMYB23 interacted with the promoter of MdANR, a key modulator of proanthocyanidin biosynthesis, and activated its expression to promote proanthocyanidin accumulation and reactive oxygen species (ROS) scavenging. MdBT2 was identified as an MdMYB23-interacting protein using yeast two-hybrid (Y2H), pull-down, and bimolecular fluorescence complementation (BiFC) assays. MdBT2 repressed cold tolerance and proanthocyanidin accumulation by promoting the degradation of MdMYB23 protein. Our findings shed light on the functions of MYB TFs and underlying mechanism in the modulation of plant cold tolerance.

Identification of Phytochrome-Interacting Factor Family Members and Functional Analysis of MdPIF4 in Malus domestica

“…Restriction endonuclease sites were EcoRI and SalI ( Table S1 ). Since MdMYB23 (GenBank accession number: MDP0000230141) has been proven to have transcriptional activity in our laboratory [ 94 ], it was able to be used as a positive control. The pGBKT7-MdPIF fusion vectors, employing the pGBKT7 vector (negative control), and pGBKT7-MdMYB23 (positive control), were transferred into the yeast strain AH109.…”

An R2R3-type MYB transcription factor MYB103 is involved in phosphate remobilization in Arabidopsis thaliana

“…Numerous MYB TFs were reported to be involved in plant responses to environmental stresses [32,33]. For example, HOS10 [34], MYB14 and MYB15 [35], and MdMYB23 [36] are involved in the modulation of cold stress response while MYB12is involved in response to nitrogen deficiency [37]. PSR1 [38] and PHR1 [12] are two well characterized R2R3 MYB transcription factors that have been implicated in the positive regulation of Pi stress responses.…”

Transcription factor genes involved in plant response to abiotic stress factors

“…Ген MdMYB23 из яблони (Malus domestica) влияет на устойчивость к холоду путем непосредственного связывания с промоторами генов MdCBF. Избыточная экспрессия MdMYB23 повышает устойчивость растений к холоду [45]. Гены AtMYB14 и AtMYB15 играют важную роль в регуляции реакции на холодовой стресс у A. thaliana [46].…”