Phytohormone abscisic acid (ABA) induces anthocyanin biosynthesis; however, the underlying molecular mechanism is less known. In this study, we found that the apple MYB transcription factor MdMYB1 activated anthocyanin biosynthesis in response to ABA. Using a yeast screening technique, we isolated MdbZIP44, an ABA-induced bZIP transcription factor in apple, as a co-partner with MdMYB1. MdbZIP44 promoted anthocyanin accumulation in response to ABA by enhancing the binding of MdMYB1 to the promoters of downstream target genes. Furthermore, we identified MdBT2, a BTB protein, as an MdbZIP44-interacting protein. A series of molecular, biochemical, and genetic analysis suggested that MdBT2 degraded MdbZIP44 protein through the Ubiquitin-26S proteasome system, thus inhibiting MdbZIP44-modulated anthocyanin biosynthesis. Taken together, we reveal a novel working mechanism of MdbZIP44-mediated anthocyanin biosynthesis in response to ABA.
Similar and dissimilar combinations of a 1000 MPa galvanised dual phase (DP) steel and a 980 MPa transformation induced plasticity (TRIP) steel were resistance spot welded under different welding and heat treatment parameters. The microstructure and mechanical properties of spot welds were evaluated using metallographic technique, microhardness and tensile shear tests. The results showed that the tendency to fail in the pullout mode increased in the order of DP/ DP, TRIP/TRIP and DP/TRIP welds, which was caused by the different hardness distribution, carbon equivalent and susceptibility to shrinkage void formation of spot welds for different combinations. In the study of the effects of heat treatments on the DP/TRIP welds, the pre-heating procedure improved the splash of welding to some extent. When the cooling time was larger than or equal to 1000 ms, the post-heating procedure improved the mechanical properties of spot welds owing to the temper of spot weld microstructure.
Teosinte branched 1/cycloidea/proliferating cell factor 1 (TCP) proteins are a large family of transcriptional regulators in angiosperms. They are involved in various biological processes, including development and plant metabolism pathways. In this study, a total of 52 TCP genes were identified in apple (Malus domestica) genome. Bioinformatic methods were employed to predicate and analyse their relevant gene classification, gene structure, chromosome location, sequence alignment and conserved domains of MdTCP proteins. Expression analysis from microarray data showed that the expression levels of 28 and 51 MdTCP genes changed during the ripening and rootstock-scion interaction processes, respectively. The expression patterns of 12 selected MdTCP genes were analysed in different tissues and in response to abiotic stresses. All of the selected genes were detected in at least one of the tissues tested, and most of them were modulated by adverse treatments indicating that the MdTCPs were involved in various developmental and physiological processes. To the best of our knowledge, this is the first study of a genomewide analysis of apple TCP gene family. These results provide valuable information for studies on functions of the TCP transcription factor genes in apple.
It is known that ethylene signaling is involved in the regulation of the salt stress response. However, the molecular mechanism of ethylene-regulated salt stress tolerance remains largely unclear. In this study, an apple NAM ATAF CUC transcription factor, MdNAC047, was isolated and functionally characterized to be involved in ethylene-modulated salt tolerance. MdNAC047 gene was significantly induced by salt treatment and its overexpression conferred increased tolerance to salt stress and facilitated the release of ethylene. Quantitative real-time-PCR analysis demonstrated that overexpression of MdNAC047 increased the expression of ethylene-responsive genes. Electrophoretic mobility shift assay, yeast one-hybrid and dual-luciferase assays suggested that MdNAC047 directly binds to the MdERF3 (ETHYLENE RESPONSE FACTOR) promoter and activates its transcription. In addition, genetic analysis assays indicated that MdNAC047 regulates ethylene production at least partially in an MdERF3-dependent pathway. Overall, we found a novel 'MdNAC047-MdERF3-ethylene-salt tolerance' regulatory pathway, which provide new insight into the link between ethylene and salt stress.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.