Plant epidermis serves important functions in shoot growth, plant defense and lipid metabolism, though mechanisms of related transcriptional regulation are largely unknown. Here, we identified cis-elements specific to shoot epidermis expression by dissecting the promoter of Triticum aestivum lipid transfer protein 1 (TaLTP1). A preliminary promoter deletion analysis revealed that a truncated fragment within 400 bp upstream from the translation start site was sufficient to confer conserved epidermis-specific expression in transgenic Brachypodium distachyon and Arabidopsis thaliana. Further, deletion or mutation of a GC(N4)GGCC motif at position −380 bp caused a loss of expression in pavement cells. With an electrophoretic mobility shift assay (EMSA) and transgenic reporter assay, we found that a light-responsive CcATC motif at position −268 bp was also involved in regulating pavement cell-specific expression that is evolutionary conserved. Moreover, expression specific to leaf trichome cells was found to be independently regulated by a CCaacAt motif at position −303 bp.

Fusarium head blight (FHB), a serious disease in wheat, causes significant reductions in grain yield and quality worldwide. Marker-assisted selection can provide an effective tool for improving FHB resistance. Although many quantitative trait loci (QTLs) associated with resistance to FHB have been reported, few loci are currently available in breeding programs. The middle and lower reaches of the Yangtze River in China are areas that historically have experienced FHB epidemics, so that some local varieties may contain some valuable genes providing FHB resistance. In this study, association mapping was performed using 103 locally cultivated varieties, and a previous QTL mapping using a recombinant inbred line population from two locally popular parents, specifically Ningmai 9 and Yangmai 158, was integrated to identify nine candidate intervals. The corresponding kompetitive allele-specific PCR markers associated with FHB resistance were successfully developed and validated in 611 breeding lines. Four loci, namely QFhb.jaas-2D, QFhb.jaas-3A, QFhb.jaas-5A.2, and QFhb.jaas-6D, proved to be significantly related to FHB resistance in addition to Fhb1, and they could provide good resistance to FHB in the absence of Fhb1; the combination of multiple loci could produce a more stable resistance. These five markers were then applied in 211 breeding lines, and many resistance lines were obtained with different combinations of resistance loci. Additionally, QFhb.jaas-3A proved to be a highly selected locus, and eight differential genes in its interval were identified by genome and transcriptome analysis. This study provides additional gene resources and materials that could be used in FHB resistance breeding in wheat.

Wheat powdery mildew is a fungal disorder caused by Blumeria graminis f. sp. tritici (Bgt) and is a severe and significant threat to the yield and quality of its host. The most practical and environmentally friendly approach to controlling this disease is through resistance gene identification to develop resistant varieties. Wild germplasm relatives of wheat are a valuable reservoir of genes contributing to resistance against powdery mildew. In our study, we identified the Aegilops tauschii germplasm “KU-2013”, exhibiting seedling resistance to Bgt isolate E09 following hexaploidization. Genetic analysis and chromosomal localization of the powdery mildew resistance gene in doubled haploid (DH) KU-2013 indicated that the disease resistance gene in DHKU-2013 is governed by a dominant gene situated in 5DS, tentatively named PmKu-2013. Following the analysis of PmKu-2013 relative to the genes at the Pm2 locus, it was inferred that PmKu-2013 represented a distinct novel gene separate from Pm2. Using molecular marker analysis, PmKu-2013 was found to be ultimately mapped between the sdau5DS5-3 and sdau5DS6-1 markers, with genetic distances of 0.6 cM and 1.3 cM, respectively. Using markers tightly linked to PmKu-2013, the genotypes of core wheat varieties from various regions were identified, laying the foundation for the transfer and utilization of PmKu-2013 in molecular-assisted selection (MAS) for breeding.