An Integrative Approach to the Flavonoid Profile in Some Plants' Parts of the Annona Genus.

The Annonaceae family is widely distributed in subtropical and tropical regions. Several species of this family are known for their pharmacological and beneficial properties to human health, mainly attributed to flavonoids. The objective of this work was to carry out an integrative review in order to identify the main flavonoids found in some plant parts belonging to the Annona genus: araticum tree (Annona crassiflora Mart.), graviola tree (Annona muricata), atemoya tree (Annona cherimolia Mill × Annona squamosa L.), pinha tree (Annona squamosa), bananinha tree (Annona leptopetala), and marolinho tree (Annona coriacea). Only articles published between the years 2016 to 2021 that answered the guiding question were considered, in order to obtain recent data. Then, search strategies were designated for each database used: Science Direct, CAPES Periodicals, and Scielo. Most of the studies retrieved from the databases are related to fruits. The results showed that the number of flavonoids identified varies according to the analytical methodology used to identify and quantify the compounds. Quercetin was the most commonly found compound in all fruits of the Annona genus studied, and epicatechin, rutin, and kaempferol were also found to a lesser extent. The presence of these compounds in Annona makes the fruit promising, with potential applicability in the pharmaceutical and food industry.

Use of pulp, peel, and seed of Annona crassiflora Mart. in elaborating extracts for fingerprint analysis using paper spray mass spectrometry.

The Brazilian cerrado is considered one of the most critical biomes in the world. Araticum (Annona crassiflora Mart.) is a native plant from the Brazilian cerrado, abundant in nutrients and highly energetic. This study aimed to obtain chemical fingerprints of different parts of the araticum fruit, i.e. pulp, peel, and seed. Extracts from these three parts were prepared using different solvents (ethanol, water, and mixtures of ethanol and water) and later analyzed by paper spray ionization mass spectrometry. In general, ethanol extracted more metabolites than the other solvents. The chemical profiles varied according to the fruit part, geographic location, and extractor solvent. Among the metabolites, acetogenins (62.3%) and alkaloids (20.7%) predominated. Principal component analyses revealed that the samples were grouped according to the fruit part, regardless of the extractor solvent used. Araticum shows remarkable potential due to the beneficial properties of the metabolites for human health. The insertion of araticum in the human diet is still underexplored but is a promising alternative.

Differential inhibition of gelatinase activity in human colon adenocarcinoma cells by Aloe vera and Aloe arborescens extracts.

BACKGROUND: Aloe's reported bioactivities (anticancer, anti-inflammatory and wound healing) suggest they might inhibit a subgroup of matrix metalloproteinases (MMPs) called gelatinases (MMP-2 and MMP-9). The goal of the present study was to compare the MMP inhibitory potential of two Aloe species, A. vera and A. arborescens. METHODS: Different types of extraction were tested and specific bioactive compounds were quantified. Cancer cell invasion inhibitory activities were measured in vitro using the wound healing assay in human colon cancer cells (HT29). Effects on gelatinase activities were further assessed by dye-quenched gelatin and gelatin zymography. RESULTS: Different types of extraction yielded significantly different levels of bioactivities and of bioactive compounds, which might be due to a greater amount of extractable bioactive compounds such as anthraquinones. Both A. arborescens and A. vera have potential as inhibitory agents in cancer cell proliferation via MMP-9 and MMP-2 enzymatic activity inhibition, being able to reduce colon cancer cell proliferation and migration but A. arborescens showed to be a more effective inhibitor of cancer cell migration than A. vera. CONCLUSION: This work opens novel perspectives on the mode of action of Aloe species in cancer cell migration and may provide clues as to why there are so many conflicting results on Aloe's activities.

The genetic legacy of fragmentation and overexploitation in the threatened medicinal African pepper-bark tree, Warburgia salutaris.

The pepper-bark tree (Warburgia salutaris) is one of the most highly valued medicinal plant species worldwide. Native to southern Africa, this species has been extensively harvested for the bark, which is widely used in traditional health practices. Illegal harvesting coupled with habitat degradation has contributed to fragmentation of populations and a severe decline in its distribution. Even though the species is included in the IUCN Red List as Endangered, genetic data that would help conservation efforts and future re-introductions are absent. We therefore developed new molecular markers to understand patterns of genetic diversity, structure, and gene flow of W. salutaris in one of its most important areas of occurrence (Mozambique). In this study, we have shown that, despite fragmentation and overexploitation, this species maintains a relatively high level of genetic diversity supporting the existence of random mating. Two genetic groups were found corresponding to the northern and southern locations. Our study suggests that, if local extinctions occurred in Mozambique, the pepper-bark tree persisted in sufficient numbers to retain a large proportion of genetic diversity. Management plans should concentrate on maintaining this high level of genetic variability through both in and ex-situ conservation actions.

Rice Biofortification With Zinc and Selenium: A Transcriptomic Approach to Understand Mineral Accumulation in Flag Leaves.

Human malnutrition due to micronutrient deficiencies, particularly with regards to Zinc (Zn) and Selenium (Se), affects millions of people around the world, and the enrichment of staple foods through biofortification has been successfully used to fight hidden hunger. Rice (Oryza sativa L.) is one of the staple foods most consumed in countries with high levels of malnutrition. However, it is poor in micronutrients, which are often removed during grain processing. In this study, we have analyzed the transcriptome of rice flag leaves biofortified with Zn (900 g ha-1), Se (500 g ha-1), and Zn-Se. Flag leaves play an important role in plant photosynthesis and provide sources of metal remobilization for developing grains. A total of 3170 differentially expressed genes (DEGs) were identified. The expression patterns and gene ontology of DEGs varied among the three sets of biofortified plants and were limited to specific metabolic pathways related to micronutrient mobilization and to the specific functions of Zn (i.e., its enzymatic co-factor/coenzyme function in the biosynthesis of nitrogenous compounds, carboxylic acids, organic acids, and amino acids) and Se (vitamin biosynthesis and ion homeostasis). The success of this approach should be followed in future studies to understand how landraces and other cultivars respond to biofortification.

Antioxidative ability and membrane integrity in salt-induced responses of Casuarina glauca Sieber ex Spreng. in symbiosis with N2-fixing Frankia Thr or supplemented with mineral nitrogen.

The actinorhizal tree Casuarina glauca tolerates extreme environmental conditions, such as high salinity. This species is also able to establish a root-nodule symbiosis with N2-fixing bacteria of the genus Frankia. Recent studies have shown that C. glauca tolerance to high salt concentrations is innate and linked to photosynthetic adjustments. In this study we have examined the impact of increasing NaCl concentrations (200, 400 and 600mM) on membrane integrity as well as on the control of oxidative stress in branchlets of symbiotic (NOD+) and non-symbiotic (KNO3+) C. glauca. Membrane selectivity was maintained in both plant groups at 200mM NaCl, accompanied by an increase in the activity of antioxidative enzymes (superoxide dismutase, ascorbate peroxidase, glutathione reductase and catalase). Regarding cellular membrane lipid composition, linolenic acid (C18:3) showed a significant decline at 200mM NaCl in both NOD+ and KNO3+ plants. In addition, total fatty acids (TFA) and C18:2 also decreased in NOD+ plants at this salt concentration, resulting in malondialdehyde (MDA) production. Such initial impact at 200mM NaCl is probably due to the fact that NOD+ plants are subjected to a double stress, i.e., salinity and low nitrogen availability. At 400mM NaCl a strong reduction of TFA and C18:3 levels was observed in both plant groups. This was accompanied by a decrease in the unsaturation degree of membrane lipids in NOD+. However, in both NOD+ and KNO3+ lipid modifications were not reflected by membrane leakage at 200 or 400mM, suggesting acclimation mechanisms at the membrane level. The fact that membrane selectivity was impaired only at 600mM NaCl in both groups of plants points to a high tolerance of C. glauca to salt stress independently of the symbiotic relation with Frankia.

Is salt stress tolerance in Casuarina glauca Sieb. ex Spreng. associated with its nitrogen-fixing root-nodule symbiosis? An analysis at the photosynthetic level.

Casuarina glauca is an actinorhizal tree which establishes root-nodule symbiosis with N2-fixing Frankia bacteria. This plant is commonly found in saline zones and is widely used to remediate marginal soils and prevent desertification. The nature of its ability to survive in extreme environments and the extent of Frankia contribution to stress tolerance remain unknown. Thus, we evaluated the ability of C. glauca to cope with salt stress and the influence of the symbiosis on this trait. To this end, we analysed the impact of salt on plant growth, mineral contents, water relations, photosynthetic-related parameters and non-structural sugars in nodulated vs. non-nodulated plants. Although the effects on photosynthesis and stomatal conductance started to become measurable in the presence of 200 mM NaCl, photochemical (e.g., photosynthetic electron flow) and biochemical (e.g., activity of photosynthetic enzymes) parameters were only strongly impaired when NaCl levels reached 600 mM. These results indicate the maintenance of high tissue hydration under salt stress, probably associated with enhanced osmotic potential. Furthermore, the maintenance of photosynthetic assimilation potential (A(max)), together with the increase in the quantum yield of down-regulated energy dissipation of PSII (Y(NPQ)), suggested a down-regulation of photosynthesis instead of photo-damaging effects. A comparison of the impact of increasing NaCl levels on the activities of photosynthetic (RubisCO and ribulose-5 phosphate kinase) and respiratory (pyruvate kinase and NADH-dependent malate dehydrogenase) enzymes vs. photosynthetic electron flow and fluorescence parameters, revealed that biochemical impairments are more limiting than photochemical damage. Altogether, these results indicate that, under controlled conditions, C. glauca tolerates high NaCl levels and that this capacity is linked to photosynthetic adjustments.

Phospholipids profile in chloroplasts of Coffea spp. genotypes differing in cold acclimation ability.

Environmental temperature change may induce modifications in membrane lipid properties and composition, which account for different physiological responses among plant species. Coffee plants, as many tropical species, are particularly sensitive to cold, but genotypes can present differences that can be exploited to improve crop management and breeding. This work intended to highlight the changes promoted by low non-freezing temperatures (chilling) in phospholipid (PL) composition of chloroplast membranes of genotypes from two Coffea species, Coffea arabica cv. Catuaí (moderately tolerant) and Coffea canephora cv. Conilon (Clone 153, more susceptible), and relate them with cold sensitivity differences. Such evaluation was performed considering a gradual temperature decrease, chilling (4 °C) exposure and a recovery period under rewarming conditions. Catuaí presented an earlier acclimation response than Clone 153 (CL 153). It displayed a higher metabolic activity during acclimation (total fatty acids and total PL increases) and chilling (phosphatidylglycerol increases), and an overall better recovery. Catuaí also showed the highest phosphatidylglycerol unsaturation (higher double bond index) after chilling, in contrast with CL 153 (gradual unsaturation decrease). Higher unsaturation degree in Catuaí than in CL 153 was also observed for phosphatidylcholine and phosphatidylinositol, resulting, mainly, from raises in unsaturated C18:2 and C18:3. It is suggested that an enhanced PL synthesis and turnover induced by a gradual cold exposure, as well as unsaturation increases in major PL classes, is related to decreased Catuaí susceptibility to low temperatures and strongly contributes to sustain photosynthetic activity in this genotype under chilling conditions, as reported in previous work by this team.

Sustained photosynthetic performance of Coffea spp. under long-term enhanced [CO2].

Coffee is one of the world's most traded agricultural products. Modeling studies have predicted that climate change will have a strong impact on the suitability of current cultivation areas, but these studies have not anticipated possible mitigating effects of the elevated atmospheric [CO2] because no information exists for the coffee plant. Potted plants from two genotypes of Coffea arabica and one of C. canephora were grown under controlled conditions of irradiance (800 µmol m(-2) s(-1)), RH (75%) and 380 or 700 µL CO2 L(-1) for 1 year, without water, nutrient or root development restrictions. In all genotypes, the high [CO2] treatment promoted opposite trends for stomatal density and size, which decreased and increased, respectively. Regardless of the genotype or the growth [CO2], the net rate of CO2 assimilation increased (34-49%) when measured at 700 than at 380 µL CO2 L(-1). This result, together with the almost unchanged stomatal conductance, led to an instantaneous water use efficiency increase. The results also showed a reinforcement of photosynthetic (and respiratory) components, namely thylakoid electron transport and the activities of RuBisCo, ribulose 5-phosphate kinase, malate dehydrogenase and pyruvate kinase, what may have contributed to the enhancements in the maximum rates of electron transport, carboxylation and photosynthetic capacity under elevated [CO2], although these responses were genotype dependent. The photosystem II efficiency, energy driven to photochemical events, non-structural carbohydrates, photosynthetic pigment and membrane permeability did not respond to [CO2] supply. Some alterations in total fatty acid content and the unsaturation level of the chloroplast membranes were noted but, apparently, did not affect photosynthetic functioning. Despite some differences among the genotypes, no clear species-dependent responses to elevated [CO2] were observed. Overall, as no apparent sign of photosynthetic down-regulation was found, our data suggest that Coffea spp. plants may successfully cope with high [CO2] under the present experimental conditions.

Biochemical and molecular characterization of the antioxidative system of Coffea sp. under cold conditions in genotypes with contrasting tolerance.

Low positive temperature (chilling) is frequently linked to the promotion of oxidative stress conditions, and is of particular importance in the coffee plant due to its severe impact on growth, development, photosynthesis and production. Nevertheless, some acclimation ability has been reported within the Coffea genus, and is possibly related to oxidative stress control. Using an integrated biochemical and molecular approach, the characterization of the antioxidative system of genotypes with different cold acclimation abilities was performed. Experiments were carried out using 1.5-year-old coffee seedlings of Coffea canephora cv. Apoatã, C. arabica cv. Catuaí, C. dewevrei and 2 hybrids, Icatu (C. arabicaxC. canephora) and Piatã (C. dewevreixC. arabica) subjected to a gradual cold treatment and a recovery period. Icatu showed the greatest ability to control oxidative stress, as reflected by the enhancement of several antioxidative components (Cu,Zn-SOD and APX activities; ascorbate, alpha-tocopherol and chlorogenic acids (CGAs) contents) and lower reactive oxygen species contents (H(2)O(2) and OH). Gene expression studies show that GRed, DHAR and class III and IV chitinases might also be involved in the cold acclimation ability of Icatu. Catuaí showed intermediate acclimation ability through the reinforcement of some antioxidative molecules, usually to a lesser extent than that observed in Icatu. On the other hand, C. dewevrei showed the poorest response in terms of antioxidant accumulation, and also showed the greatest increase in OH values. The difference in the triggering of antioxidative traits supports the hypothesis of its importance to cold (and photoinhibition) tolerance in Coffea sp. and could provide a useful probe to identify tolerant genotypes.