The genome and phenome of the green alga Chloroidium sp. UTEX 3007 reveal adaptive traits for desert acclimatization.

To investigate the phenomic and genomic traits that allow green algae to survive in deserts, we characterized a ubiquitous species, Chloroidium sp. UTEX 3007, which we isolated from multiple locations in the United Arab Emirates (UAE). Metabolomic analyses of Chloroidium sp. UTEX 3007 indicated that the alga accumulates a broad range of carbon sources, including several desiccation tolerance-promoting sugars and unusually large stores of palmitate. Growth assays revealed capacities to grow in salinities from zero to 60 g/L and to grow heterotrophically on >40 distinct carbon sources. Assembly and annotation of genomic reads yielded a 52.5 Mbp genome with 8153 functionally annotated genes. Comparison with other sequenced green algae revealed unique protein families involved in osmotic stress tolerance and saccharide metabolism that support phenomic studies. Our results reveal the robust and flexible biology utilized by a green alga to successfully inhabit a desert coastline.

Profiling of primary metabolites and flavonols in leaves of two table grape varieties collected from semiarid and temperate regions.

Cultivation of grapes in West Bank - Palestine is very old and a large number of grape varieties exist as a result of continuous domestication over thousands of years. This rich biodiversity has highly influenced the consumer behavior of local people, who consume both grape berries and leaves. However, studies that address the contents of health-promoting metabolites in leaves are scarce. Accordingly the aim of this study is to assess metabolite levels in leaves of two grape varieties that were collected from semiarid and temperate regions. Metabolic profiling was conducted using GC-MS and LC-MS. The obtained results show that abiotic stresses in the semiarid region led to clear changes in primary metabolites, in particular in amino acids, which exist at very high levels. By contrast, qualitative and genotype-dependent differences in secondary metabolites were observed, whereas abiotic stresses appear to have negligible effect on the content of these metabolites. The qualitative difference in the flavonol profiles between the two genotypes is most probably related to differential expression of specific genes, in particular flavonol 3-O-rhamnosyltransferase, flavonol-3-O-glycoside pentosyltransferases and flavonol-3-O-d-glucosidel-rhamnosyltransferase by 'Beituni' grape leaves, which led to much higher levels of flavonols with rutinoside, pentoside, and rhamnoside moieties with this genotype.

Changes in polyphenols and expression levels of related genes in 'Duke' blueberries stored under high CO2 levels.

Blueberries are highly perishable fruits, and consequently, storage under high CO2 and low O2 levels is recommended to preserve the highly appreciated polyphenols. However, high CO2 levels might be detrimental for certain cultivars. The aim of this study was to investigate the impact of storage conditions on various quality parameters, including polyphenol composition in 'Duke' berries. Results show that storage under 18 kPa CO2, coupled with 3 kPa O2, resulted in accelerated softening of berries, which was accompanied by lower levels compared to other conditions of hexosides and arabinosides of malvidin, petunidin, cyanidine, and delphinidin. However, this storage condition had no negative impact on chlorogenic acid levels. Expression data of key polyphenol-biosynthesis genes showed higher expression levels of all investigated genes at harvest time compared to all storage conditions. Of particular importance is the expression level of chalcone synthase (VcCHS), which is severely affected by storage at 18 kPa CO2.

Correlation between changes in polyphenol composition of peels and incidence of CO2 skin burning of 'Cameo' apples as influenced by controlled atmosphere storage.

'Cameo' apples stored under high CO2 levels suffer from "skin burning". Accordingly, this study is aimed to correlate the incidence of skin burning with different polyphenols. After harvest, apples were sorted into bad- and good-colored fruit and further stored under either high (3%) or low (0.7%) CO2 level. At frequent intervals, fruit were assessed for incidence of skin burning and relative concentrations of various polyphenols. Results clearly show that bad-colored apples stored under high CO2 level had the highest incidence percentage. Concerning the polyphenol profile, good-colored and healthy apples had significantly higher concentrations of certain polyphenols, including cyanidin-3-galactoside and rutin. However, bad-colored and injured apples had significantly higher concentrations of another set of polyphenols, including phloridzin, epicatechin, and (epi)catechin→(epi)catechin isomers. Taking into account that quercetins and cyanidins account for more than 80% of antioxidants, it is logical to assume that these polyphenols might give protection to good-colored apples against skin burning.