R2R3-MYB transcription factors (TFs) form one of the most important TF families involved in regulating various physiological functions in plants. The heartwood of Dalbergia odorifera is a kind of high-grade mahogany and valuable herbal medicine with wide application. However, the role of R2R3-MYB genes in the growth and development of D. odorifera, especially their relevance to heartwood formation, has not been revealed. A total of 126 R2R3-MYBs were screened from the D. odorifera genome and named DodMYB1-126 based on their location on 10 chromosomes. The collinearity results showed that purification selection was the main driving force for the evolution of the R2R3-MYB TFs family, and whole genome/fragment replication event was the main form for expanding the R2R3-MYB family, generating a divergence of gene structure and function. Comparative phylogenetic analysis classified the R2R3-MYB TFs into 33 subfamilies. S3-7,10,12-13,21 and N4-7 were extensively involved in the metabolic process; S9,13,16-19,24-25 and N1-3,8 were associated with the growth and development of D. odorifera. Based on the differential transcriptional expression levels of R2R3-MYBs in different tissues, DodMYB32, DodMYB55, and DodMYB89 were tentatively screened for involvement in the regulatory process of heartwood. Further studies have shown that the DodMYB89, localized in the nucleus, has transcriptional activation activity and is involved in regulating the biosynthesis of the secondary metabolites of heartwood by activating the promoters of the structural genes DodI2’H and DodCOMT. This study aimed to comprehensively analyze the functions of the R2R3-MYB TFs and screen for candidate genes that might be involved in heartwood formation of D. odorifera.

Wheat is one of the most important crops contributing to global food and nutritional security. However, the gradual increase in soil salt content significantly impairs wheat growth and development, ultimately resulting in reduced yields. Therefore, enhancing the salt tolerance of wheat is of significant importance. Salt stress commonly induces oxidative stress in plants, and nucleoredoxin (NRX) has been shown to effectively maintain redox homeostasis under stress conditions. However, the functional role and molecular mechanism of the NRX gene in regulating salt tolerance in wheat remain to be elucidated. The results of this study demonstrated that TaNRX1-2D homologous overexpression (OE) lines exhibited significantly enhanced tolerance to salt stress. The survival rate and antioxidant enzyme activities (including superoxide dismutase and catalase) in the OE lines were higher than those in the wild type (WT). In contrast, the levels of superoxide anion (O₂⁻), hydrogen peroxide (H₂O₂), and malondialdehyde (MDA) in the OE lines were markedly lower than those in the WT. Conversely, the RNA interference (RNAi) lines displayed opposing trends. The results of yeast one-hybrid (Y1H) and dual luciferase assays (D-LUC) demonstrated that the TaERD15L-3B transcription factor positively regulated the expression of the TaNRX1-2D gene by binding to the ABRERATCAL cis-acting element in the TaNRX1-2D promoter. Through luciferase complementation assay (LCA), bimolecular fluorescence complementation (BiFC) assay, and a “mutation capture strategy”, it was found that TaNRX1-2D (C54, 327S) interacted with TaCAT2-B, indicating that TaCAT2-B was the target protein of TaNRX1-2D. The results of data-independent acquisition (DIA) proteomics analysis indicated that TaNRX1-2D may mediate salt tolerance in wheat through the positive regulation of nsLTP protein abundance and the negative regulation of hexokinase protein abundance. In general, the TaERD15L-3B/TaNRX1-2D regulatory module played a crucial role in conferring salt tolerance in wheat. This study provided an important theoretical basis and identified a potential gene target for developing salt-tolerant wheat varieties through molecular breeding approaches.