The presence of fruits provokes significant modifications in plant water relations and leaf gas exchange. The underlying processes driving these modifications are still uncertain and likely depend on ...the water deficit level. Our objective was to explain and track the modification of leaf-water relations by the presence of fruits and water deficit. With this aim, net photosynthesis rate (AN), stomatal conductance (gs), leaf osmotic potential (Ψπ), leaf soluble sugars and daily changes in a variable related to leaf turgor (leaf patch pressure) were measured in olive trees with and without fruits at the same time, under well-watered (WW) and water stress (WS) conditions. Leaf gas exchange was increased by the presence of fruits, this effect being observed mainly in WW trees, likely because under severe water stress, the dominant process is the response of the plant to the water stress and the presence of fruits has less impact on the leaf gas exchange. Ψπ was also higher for WW trees with fruits than for WW trees without fruits. Moreover, leaves from trees without fruits presented higher concentrations of soluble sugars and starch than leaves from trees with fruits for both WW and WS, these differences matching those found in Ψπ. Thus, the sugar accumulation would have had a dual effect because on one hand, it decreased Ψπ, and on the other hand, it would have downregulated AN, and finally gs in WW trees. Interestingly, the modification of Ψπ by the presence of fruits affected turgor in WW trees, the change in which can be identified with leaf turgor sensors. We conclude that plant water relationships and leaf gas exchange are modified by the presence of fruits through their effect on the export of sugars from leaves to fruits. The possibility of automatically identifying the onset of sugar demand by the fruit through the use of sensors, in addition to the water stress produced by soil water deficit and atmosphere drought, could be of great help for fruit orchard management in the future.
•The use of LED lights increases the inhibitory effects of polyphenols on digestive enzymes.•LED light treatments enhanced contents of anthocyanins, polyphenols and fruit yield.•These results will ...facilitate the development of commercial scale LED systems.
Strawberries are a widely consumed fruit that are increasingly popular due to the perceived health benefits associated with their consumption. Fruit quality is highly dependent on the growing environment where light is one of the most significant environmental factors influencing plant physiology and metabolism. In the present work we sought to test the hypothesis that manipulation of the light environment in a commercial growing environment would influence fruit yield and quality. Fruit were grown with supplemental light-emitting diodes in the red (623 nm), far-red (727 nm) and blue (470 nm) regions of the spectrum at three different densities. The majority of light treatments resulted in increased fruit yield. All treatments also significantly enhanced contents of anthocyanins and polyphenols. Furthermore fruit exhibited enhanced antioxidant activity. Individual strawberry sugars showed differences depending on sampling date whereas Brix, acidity and ascorbic acid was not affected by the LED lights. Strawberry fruit extracts from all treatments exhibited the capacity to inhibit the digestive enzymes pancreatic lipase and α-amylase activity in vitro, extract from fruit grown under supplemental lighting had a greater inhibitory capacity. These data suggest that strawberry fruit grown in the presence of supplemental light may impart health benefits via enhanced functional compounds and by limiting calorific assimilation. The findings of this study provide the first evidence that the use of light-emitting diodes increase the inhibitory effects of polyphenols on digestive enzymes in strawberry.
•Polymeric nanoparticles of γ-polyglutamic and chitosan for agricultural application.•New nanoparticles as delivery systems for the plant growth regulator gibberellic acid.•Nanoformulations increase ...the biological activity of the gibberellic acid in Phaseolus vulgaris.•System showed potential to a broad range of agriculture applications aiming the plant development.
The growth regulator gibberellic acid (GA3) has several uses in the field, improving germination, plant development, productivity, and the quality of food. This work describes the development of a nanocarrier system for GA3, based on the poly(γ-glutamic acid) (γ-PGA) and chitosan (CS) polymers, Nanoparticles without GA3 (nano-γPGA/CS-GA3) showed colloidal characteristics, with an average size of 117±9nm, PDI of 0.43±0.07, and zeta potential of −29±0.5mV. The encapsulated nanoparticles (nano-γPGA/CS-GA3) presented an average size of 134±9nm, PDI of 0.35±0.05, zeta potential of 27.9±0.5mV, and 61% encapsulation. The images of nanoparticles observed by Transmission and scanning electron microscopy (TEM and SEM) showed a spherical shape of the nanoparticles. The system showed sustained release, with 58% release after 48h. Evaluation of thermal properties using DSC and TGA analyses indicated that there was an interaction between the CS and γ-PGA polymers. In tests using Phaseolus vulgaris seeds, nano-γPGA/CS-GA3 showed high biological activity, enhancing the rate of germination in the first day (50–70%) when compared with free GA3 (10–16%). Encapsulated GA3 was also more efficient than the free hormone in the increase of leaf area and the induction of root development (including the formation of lateral roots). These effects were not observed when seeds were treated with nano-γPGA/CS without GA3. The results demonstrated the considerable potential of nano-γPGA/CS-GA3 for use in agriculture.
To evaluate the effect of the management system on soil quality, chemical and biological properties were measured in soils (0-20 cm depth) from Japanese plum orchards managed under organic and ...conventional conditions. The experiment was conducted between 2005 and 2014 in orchards established at the agricultural research station at Alcalá del Río, Seville, Spain. Overall, the soil chemical parameters in the organic orchard showed higher concentrations of soil organic matter, total N, available P and Mg. There was a trend of higher concentrations of K and Na, though for these elements the differences were significant only in two and one years, respectively. Similarly, concentrations of Mn and Zn tended to be higher in the organic plots, whereas contradictory trends were shown for Fe and Cu. No differences were found between the treatments for other physicochemical parameters such as pH and electrical conductivity. Regarding soil biological properties, the organic system was characterised with a significantly greater abundance of bacteria and fungi compared with the conventional system. The rhizobia population and the legume biomass were also higher in the organic orchard and the plants had more nodules. Likewise, the number of earthworms was higher in the organic system. The results showed that long-term organic management, including the use of cover crops and compost, resulted in a significant shift of the chemical and biological characteristics of the soil compared with the conventional management practice, thus improving soil quality and suggesting that organic farming may provide a potential solution to achieve sustainable agricultural systems.
The number of local and traditional fruit cultivars in Andalusia (Southern Spain) has decreased dramatically since the 1970s when new commercial cultivars from breeding programs were introduced, ...replacing old varieties, and thus decreasing genetic diversity. The present study was included in a genetic resources project with the objective of identifying and preserving traditional fruit tree cultivars in Southern Spain. The goal of this study was to begin the characterization of 29 apple accessions (Malus x domestica Borkh) belonging to 13 traditional cultivar denominations. For molecular characterization studies, 12 simple sequence repeat markers previously developed for apple species were used. Morphological characterization was performed using 33 fruit traits. A total of 115 alleles were amplified for the 12 loci, ranging from 7 (CH01h01, CH01h10, and GD 12) to 13 alleles per locus (CH02c11). Forty-one alleles were unique to specific genotypes. The locus with the highest number of detected unique alleles was CH01f03b with 6 alleles. Expected heterozygosity ranged from 0.74 for CH01h10 to 0.88 for CH02c11, with an average of 0.82. Observed heterozygosity varied from 0.45 for CH01h01 to 1.0 for CH02d08, with an average of 0.86. Three homonyms were found for accessions belonging to varieties 'Maguillo', 'Pero Minguela', and 'Castellana'. The most discriminant morphological characters studied revealed no homonyms or synonyms among cultivar denominations, although they are useful for describing varietal characteristics that have not been previously defined.
Congenital extrahepatic portosystemic shunt (CEPS) or Abernethy malformation is a rare condition in which splanchnic venous blood bypasses the liver draining directly into systemic circulation ...through a congenital shunt. Patients may develop hepatic encephalopathy (HE), pulmonary hypertension (PaHT), or liver tumors, among other complications. However, the actual incidence of such complications is unknown, mainly because of the lack of a protocolized approach to these patients. This study characterizes the clinical manifestations and outcome of a large cohort of CEPS patients with the aim of proposing a guide for their management. This is an observational, multicenter, international study. Sixty‐six patients were included; median age at the end of follow‐up was 30 years. Nineteen patients (28%) presented HE. Ten‐, 20‐, and 30‐year HE incidence rates were 13%, 24%, and 28%, respectively. No clinical factors predicted HE. Twenty‐five patients had benign nodular lesions. Ten patients developed adenomas (median age, 18 years), and another 8 developed HCC (median age, 39 years). Of 10 patients with dyspnea, PaHT was diagnosed in 8 and hepatopulmonary syndrome in 2. Pulmonary complications were only screened for in 19 asymptomatic patients, and PaHT was identified in 2. Six patients underwent liver transplantation for hepatocellular carcinoma or adenoma. Shunt closure was performed in 15 patients with improvement/stability/cure of CEPS manifestations. Conclusion: CEPS patients may develop severe complications. Screening for asymptomatic complications and close surveillance is needed. Shunt closure should be considered both as a therapeutic and prophylactic approach.
Abstract
The differential stomatal regulation of transpiration among plant species in response to water deficit is not fully understood, although several hydraulic traits have been reported to ...influence it. This knowledge gap is partly due to a lack of direct and concomitant experimental data on transpiration, stomatal conductance, and hydraulic traits. We measured sap flux density (Js), stomatal conductance (gs), and different hydraulic traits in five crop species. Our aim was to contribute to establishing the causal relationship between water consumption and its regulation using a hydraulic trait-based approach. The results showed that the species-specific regulation of Js by gs was overall coordinated with the functional hydraulic traits analysed. Particularly relevant was the negative and significant relationship found between the Huber value (Hv) and its functional analogue ratio between maximum Js and gs (Jsmax/gsmax) which can be understood as a compensation to maintain the hydraulic supply to the leaves. The Hv was also significantly related to the slope of the relationship between gs and Js response to vapour pressure deficit and explained most of its variability, adding up to evidence recognizing Hv as a major trait in plant water relations. Thus, a hydraulic basis for regulation of tree water use should be considered.
We found coordination between stomatal regulation of tree transpiration and hydraulic traits, with the Huber value being the trait with the most predominant role in the stomatal control–water use relationship.
The performance of Polyethylene (PE)/Clay/Silver nanocomposites is dependent to a great extent on the properties of filler-matrix interface. To improve the interfacial properties in PE/Clay/Silver ...composites, different types of compatibilizers or adhesion promoters were introduced. The compatibilization provided by maleic anhydride (MA), itaconic acid (IA) and 2-2-(dimethylamine)-ethoxy ethanol (DMAE) functionalized PEs for forming PE-based nanocomposites was studied and compared. IA was grafted into PE by melt mixing to obtain PEgIA (compatibilizer 1), thereafter, PEgIA and PEgMA (compatibilizer 2) were reacted with DMAE also by melt mixing to obtain PEgI-DMAE (compatibilizer 3) and PEgM-DMAE (compatibilizer 4). These compatibilizers were reacted using ultrasound with a solution of AgNO
3
0.04 M and ethylene glycol. Ammonium hydroxide was added in a ratio of 2:1 M with respect to silver nitrate. These silver coated compatibilizers were mixed with PE and with a quaternary ammonium modified montmorillonite clay (Nanomer I28E), thus forming the different hybrid PE/Clay/Silver nanocomposites. FTIR confirmed the formation of these compatibilizers. All the DMAE compatibilized nanocomposites had better filler (clay and silver) dispersion and exfoliation. XRD, oxygen and water transmission rate as well as antimicrobial properties attained showed that the PEgI-DMAE produced the better dispersed PE, clay and silver nanocomposites. The obtained nanocomposites showed enhanced barrier properties and outstanding antimicrobial properties against bacteria, E. coli. PEgI-DMAE offers an outstanding capability for preparing nanocomposites with highly exfoliated and dispersed filler into the PE matrix that offers a new option for obtaining hybrid nanocomposites with enhanced properties to be used in packaging applications.
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