Stage- and tissue-expression of genes involved in the biosynthesis and signalling of ethylene in reproductive organs of damson plum (Prunus domestica L. subsp. insititia)

The influence of ripening on the nutrient composition and antioxidant properties of New Zealand damson plums

The current study pioneers a comprehensive exploration into the influence of ripening stages on the nutritional composition and antioxidant attributes of the New Zealand damson plums (Prunus domestica ssp. Insititia). Sampled at early-, mid-, and late-ripening stages from randomly selected plum trees, the investigation unveiled notable significant (p < .05) declines in multiple parameters as ripening progressed. Noteworthy reductions in dry matter (from 21% to 19.33%), stone weight (from 30.23% to 24.30%), total dietary fiber (from 3.15% to 2.5%), energy content (from 280 to 263 kJ/100 g), vitamin D3 (from 1.67 to 1.53 μg/100 g), vitamin A (from 4.2 to 3.87 μg/100 g), and specific minerals (e.g., Ca, Mg, and P) emerged as a hallmark of this progression. Additionally, plums harvested at the advanced ripening stage exhibited heightened moisture content in contrast to their early-stage counterparts. Conversely, ash, protein, carbohydrates, total sugar, and minerals (including K, Na, Zn, and Se) demonstrated no significant alteration (p > .05) across ripening stages. Remarkably, damson plums that were harvested at the end of the ripening stage displayed reduced phenolic content and total antioxidant activity compared to those acquired at the early-mid ripening phase. This research collectively highlights the substantive impact of harvesting time and ripening stage on the nutritional and antioxidant profiles of damson plums cultivated in New Zealand.

New approaches to Prunus transcriptome analysis

The recent sequencing of the complete genome of the peach offers new opportunities for further transcriptomic studies in Prunus species in the called post-genomics era. First works on transcriptome analysis in Prunus species started in the early 2000s with the development of ESTs (expressed sequence tags) and the analysis of several candidate genes. Later, new strategies of massive analysis (high throughput) of transcriptomes have been applied, producing larger amounts of data in terms of expression of a large number of genes in a single experiment. One of these systems is massive transcriptome analysis using cDNA biochips (microarrays) to analyze thousands of genes by hybridization of mRNA labelled with fluorescence. However, the recent emergence of a massive sequencing methodology ("deep-sequencing") of the transcriptome (RNA-Seq), based on lowering the costs of DNA (in this cases complementary, cDNA) sequencing, could be more suitable than the application of microarrays. Recent papers have described the tremendous power of this technology, both in terms of profiling coverage and quantitative accuracy in transcriptomic studies. Now this technology is being applied to plant species, including Prunus. In this work, we analyze the potential in using this RNA-Seq technology in the study of Prunus transcriptomes and the development of genomic tools. In addition, the strengths and limitations of RNA-Seq relative to microarray profiling have been discussed.

Organic Acids and Soluble Sugars in Edible and Nonedible Parts of Damson Plum (Prunus domestica L. subsp. insititia cv. Syriaca) Fruits During Development and Ripening

The contribution of the seed and pericarp to the content of malic, quinic, citric and fumaric acids, and sucrose, fructose and glucose was determined during development and ripening of damson plum fruits. In whole fruit, (i) malic and quinic acids were the principal organic acids (OA) and their levels varied significantly, the highest being found at the beginning of the late-green stage; and (ii) the content of citric and fumaric acids was scarce but fluctuated remarkably towards development and ripening. In the seed, the levels of malic, quinic and fumaric acid were lower in ripening than at the beginning of maturation, and a notable synthesis of citric was found from the middle of maturation onwards. In mesocarp, however, malic, quinic, and citric acids peaked in the middle of maturation, whereas fumaric acid notably increased towards ripening. In epicarp, the maximum for the quinic and malic was found at the beginning of ripening and maturation, respectively. In the seed, all soluble sugars (SS) studied peaked at the middle of maturation, and while fructose and glucose (the most abundant SS) tended to be stored during ripening, sucrose (the most abundant in the edible part of fruit) decreased. All the SS studied tend to increase in mesocarp and epicarp throughout maturation and ripening.