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The major latex protein/ripening-related protein (MLP/RRP) subfamily is known to be involved in a wide range of biological processes of plant development and various stress responses. However, the biological function of MLP/RRP proteins is still far from being clear and identification of them may provide important clues for understanding their roles. Here, we report a genome-wide evolutionary characterization and gene expression analysis of the MLP family in European Vitis species. A total of 14 members, was found in the grape genome, all of which are located on chromosome 1, where are predominantly arranged in tandem clusters. We have noticed, most surprisingly, promoter-sharing by several non-identical but highly similar gene members to a greater extent than expected by chance. Synteny analysis between the grape and Arabidopsis thaliana genomes suggested that 3 grape MLP genes arose before the divergence of the two species. Phylogenetic analysis provided further insights into the evolutionary relationship between the genes, as well as their putative functions, and tissue-specific expression analysis suggested distinct biological roles for different members. Our expression data suggested a couple of candidate genes involved in abiotic stresses and phytohormone responses. The present work provides new insight into the evolution and regulation of Vitis MLP genes, which represent targets for future studies and inclusion in tolerance-related molecular breeding programs. [ABSTRACT FROM AUTHOR]

Flower-specific promoters can enable transgenic enhancement of valuable ornamental traits, including flower shape and color. However, the identification of strong, tissue-specific promoters remains a limiting factor. To obtain enhanced flower-specific promoters, we constructed four chimeric promoters (p35S- PCHS-Ω, p35S- LCHS-Ω, pOCS- PCHS-Ω and pOCS- LCHS-Ω) combining the 35S or OCS enhancer fused to a 302 bp CHSA core promoter fragment from petunia ( PCHS) or a 307 bp CHS core promoter fragment from lily ( LCHS), and also containing an omega element (Ω). Each promoter was fused to the β-glucuronidase ( GUS) reporter gene, and we examined the levels and tissue specificity of GUS expression in transgenic Torenia fournieri. p35S- PCHS-Ω and p35S- LCHS-Ω drove strong, constitutive GUS expression in all tissues, especially in colored corollas (p35S- PCHS-Ω) or in colored corollas and roots (p35S- LCHS-Ω). pOCS- PCHS-Ω drove stronger GUS expression in colored corollas than in other tissues but expression was weaker than that of p35S- PCHS-Ω. pOCS- LCHS-Ω drove GUS in colored corollas but also in roots. Among the four chimeric promoters, pOCS- PCHS-Ω exhibited stronger activity only in colored corollas, making it useful for transgenic enhancement of floral traits, such as expressing 'blue genes' in lily to produce new lines with blue flowers. [ABSTRACT FROM AUTHOR]