Hydraulic tradeoffs underlie enhanced performance of polyploid trees under soil water deficit.

The relationships between aerial organ morpho-anatomy of woody polyploid plants with their functional hydraulics under water stress remain largely understudied. We evaluated growth-associated traits, aerial organ xylem anatomy, and physiological parameters of diploid, triploid, and tetraploid genotypes of atemoyas (Annona cherimola × Annona squamosa), which belong to the woody perennial genus Annona (Annonaceae), testing their performance under long-term soil water reduction. The contrasting phenotypes of vigorous triploids and dwarf tetraploids consistently showed stomatal size-density tradeoff. The vessel elements in aerial organs were ∼1.5 times wider in polyploids compared with diploids, and triploids displayed the lowest vessel density. Plant hydraulic conductance was higher in well-irrigated diploids while their tolerance to drought was lower. The phenotypic disparity of atemoya polyploids associated with contrasting leaf and stem xylem porosity traits that coordinate to regulate water balances between the trees and the belowground and aboveground environments. Polyploid trees displayed better performance under soil water scarcity, and consequently, could present more sustainable agricultural and forestry genotypes to cope with water stress.

Relation between Strawberry Fruit Redness and Bioactivity: Deciphering the Role of Anthocyanins as Health Promoting Compounds.

The red colour of most berries is often associated to fruit healthiness, since it has been linked to enrichment in anthocyanins (polyphenol with antioxidative properties). However, recent studies suggest that anthocyanins could not be the major contributors to bioactivity leading to uncertainty about their role as important molecules in the generation of health-promoting properties. To shed light on this issue, spectrophotometric and HPLC techniques were used for characterizing the content of phenolic compounds, including anthocyanins, in fruits of red (Fragaria x ananassa, cv. Fortuna) and white strawberry (Fragaria vesca spp. XXVIII) species (distinguishing receptacle from achene). In addition, the effect of these extracts on the reduction of intracellular ROS was tested, as well as on the activity of antioxidant enzymes and the quantification of cell oxidation markers. The results showed that white receptacle extracts (deprived of anthocyanins) were able to protect cells from oxidative damage to a greater extent than red fruits. This could be due per se to their high antioxidant capacity, greater than that shown in red fruits, or to the ability of antioxidants to modulate the activity of antioxidant enzymes, thus questioning the positive effect of anthocyanins on the wholesomeness of strawberry fruits. The results shed light on the relevance of anthocyanins in the prevention of health-associated oxidative damage.

Strawberry and Achenes Hydroalcoholic Extracts and Their Digested Fractions Efficiently Counteract the AAPH-Induced Oxidative Damage in HepG2 Cells.

Strawberry fruits are highly appreciated by consumers worldwide due to their bright red color, typical aroma, and juicy texture. While the biological activity of the complete fruit has been widely studied, the potential beneficial effects of the achenes (commonly named seeds) remain unknown. In addition, when raw fruit and achenes are consumed, the digestion process could alter the release and absorption of their phytochemical compounds, compromising their bioactivity. In the present work, we evaluated the protective effects against oxidative damage of nondigested and digested extracts from strawberry fruit and achenes in human hepatocellular carcinoma (HepG2) cells. For that purpose, cells were treated with different concentration of the extracts prior to incubation with the stressor agent, AAPH (2,2'-azobis(2-amidinopropane) dihydrochloride). Subsequently, intracellular accumulation of reactive oxygen species (ROS) and the percentage of live, dead, and apoptotic cells were determined. Our results demonstrated that all the evaluated fractions were able to counteract the AAPH-induced damage, suggesting that the achenes also present biological activity. The positive effects of both the raw fruit and achenes were maintained after the in vitro digestion process.

Bioaccessibility and potential bioavailability of phenolic compounds from achenes as a new target for strawberry breeding programs.

Strawberry is a major natural source of bioactive compounds. Botanically, strawberry is an aggregate fruit consisting of a fleshy floral receptacle that bears a cluster of real dry fruits (achenes). Existing knowledge on the phenolic composition of achenes and its contribution to that of the whole fruit is limited. Also, the gastric and intestinal bioavailability of phenols is poorly known. In this work, a combination of spectrophotometric and HPLC-DAD methods was used to analyse the phenolic composition of whole fruits and achenes before and after in vitro digestion. Five different phenol families were identified. Also, achenes were found to contribute a sizeable fraction of phenolic acids and hydrolysable tannins in the whole fruit. Because the mere presence of phenolic compounds in a food matrix does not ensure their ready absorption and bioavailability, polyphenol potential bioavailability could be an effective selection criterion for strawberry breeding programs aimed at improving dietary healthiness.