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The involvement of effectors and transcriptional regulators in persimmon fruit maturation has been mostly approached by the literature under postharvest conditions. In order to elucidate the participation of these genes in the on-tree fruit maturation development, we have collected samples from seven persimmon germplasm accessions at different developmental stages until physiological maturation. This study has focused on the expression analysis of 13 genes involved in ethylene biosynthesis and response pathways, as well as the evolution of important agronomical traits such as skin colour, weight, and firmness. Results revealed different gene expression patterns, with genes up- and down-regulated during fruit development progression. A principal component analysis was performed to correlate gene expression with agronomical traits. The decreasing expression of the ethylene biosynthetic genes DkACO1 , DkACO2, and DkACS2 , in concordance with other sensing ( DkERS1 ) and transduction genes ( DkERF18 ), provides a molecular mechanism for the previously described high production of ethylene in immature detached fruits. On the other side, DkERF8 and DkERF16 are postulated to induce fruit softening and skin colour change during natural persimmon fruit ripening via DkXTH9 and DkPSY activation, respectively. This study provides valuable information for a better understanding of the ethylene signalling pathway and its regulation during on-tree fruit ripening in persimmon.

Transcriptomic and gene expression analysis have greatly facilitated the identification and characterization of transcriptional regulatory factors and effectors involved in dormancy progression and other physiological processes orchestrated during bud development in peach and other temperate fruit species. Gene expression measurements are most usually based on average values from several or many individual buds. We have performed single-bud gene analysis in flower buds of peach across dormancy release using amplicons from the master regulatory DORMANCY-ASSOCIATED MADS-BOX ( DAM ) factors, several jasmonic acid biosynthetic genes, other genes related to flowering development, cell growth resumption, and abiotic stress tolerance. This analysis provides a close view on gene-specific, single-bud variability throughout the developmental shift from dormant to dormancy-released stages, contributing to the characterization of putative co-expression modules and other regulatory aspects in this particular tissue.

Pomegranates were one of the first domesticated fruit crops, and their long history resulted in the development of local cultivars all over the world. Spain is one of the main producers and exporters of this crop in the Mediterranean Basin, but in order to maintain the competitiveness of this crop, new varieties should be developed. For this purpose, the pomegranate germplasm collection hold at the Agricultural Experiment Station of Elche, a public institution dependent on the Valencian regional government, is an interesting tool. However, the detailed characterization of any germplasm collection is a fundamental requirement to be able to make the most of these resources, allowing to identify putative promising accessions and to optimize the design of the future crosses. In this work, the genetic diversity of 94 accessions of this collection was analyzed using 19 microsatellite markers. As a result, 85 different genotypes were identified. These genetic profiles could be useful for varietal identification. Despite this genetic diversity, no clear substructure was observed, except for the ornamental accessions, that could be related to the vegetative propagation of the species. Additionally, the morphological characterization of this collection has made it possible to identify some materials that may be of interest as a source of traits for breeding. Results presented here pave the way for further genetic analyses, allowing the selection of parents to obtain segregating populations, as well as their descendants by the use of molecular assisted selection.