Talaromyces marneffei isolated from nasal swabs in Portugal.

Mycobiota are essential to the health of any living being, creating a balanced and complex interaction between bacteria, the immune system, and the tissue cells of the host. Talaromyces marneffei (also known as Penicillium marneffei) is a dimorphic fungus, endemic in South Asia, which often causes a life-threatening systemic fungal infection (called penicilliosis), particularly in immunocompromised hosts. Nasal swabs from 73 healthy volunteers were analysed to characterize their mycobiota, through its cultural characteristics, morphology, and molecular methods (PCR). All volunteers were also asked to answer to an anonymous questionnaire. Three women were positive (and asymptomatic) for T. marneffei. One of them was reported to have lupus. This study contributes to improving our knowledge about human normal mycobiota, identifying mycotic agents that may cause complicated systemic infections (as T. marneffei), especially in immunosuppressed patients, as well as other possible risk factors of exposure or prognosis.

• Talaromyces marneffei is a zoonotic fungus that may be responsible for life-threatening systemic infections in immune-comprised patients. • Talaromyces marneffei was identified in nasal swabs from asymptomatic volunteers. • This suggests that this fungus may be part of the nasal normal mycobiota of some humans.

Effects of exogenous compound sprays on cherry cracking: skin properties and gene expression.

BACKGROUND: Cherry fruit cracking is a costly problem for cherry growers. The effect of repeated sprayings (gibberellic acid - GA3 ; abscisic acid - ABA; salicylic acid - SA; glycine betaine - GB, and Ascophyllum nodosum - AN) combined with CaCl2 , on 'Sweetheart' cherry fruit-cracking characteristics was investigated. Cracking was quantified in terms of cracking incidence, crack morphology, confocal scanning laser microscopy, cuticular wax content, cell-wall modification, and cuticular wax gene expression. RESULTS: All spray treatments reduced cracking compared with an untreated control (H2 O), with fewer cheek cracks. The least cracking incidence was observed for ABA + CaCl2 - and GB + CaCl2 -treated fruits, indicating an added benefit compared to spraying with CaCl2 alone. In addition, GB + CaCl2 -treated fruits showed higher fruit diameter. ABA + CaCl2 and GB + CaCl2 sprays showed higher wax content and higher cuticle and epidermal thickness compared with the control, including increased expression of wax synthase (ABA + CaCl2 ) and expansin 1 (GB + CaCl2 ). CONCLUSION: In general, factors that improve the cuticle thickness appear to be important at the fruit-coloring stage. At the fruit-ripening stage, larger cell sizes of the epidermis, hypodermis, and parenchyma cells lower cracking incidence, indicating the importance of flexibility and elasticity of the epidermis. © 2020 Society of Chemical Industry.

Genetic diversity and structure of Iberian Peninsula cowpeas compared to world-wide cowpea accessions using high density SNP markers.

BACKGROUND: Cowpea (Vigna unguiculata L. Walp) is an important legume crop due to its high protein content, adaptation to heat and drought and capacity to fix nitrogen. Europe has a deficit of cowpea production. Knowledge of genetic diversity among cowpea landraces is important for the preservation of local varieties and is the basis to obtain improved varieties. The aims of this study were to explore diversity and the genetic structure of a set of Iberian Peninsula cowpea accessions in comparison to a worldwide collection and to infer possible dispersion routes of cultivated cowpea. RESULTS: The Illumina Cowpea iSelect Consortium Array containing 51,128 SNPs was used to genotype 96 cowpea accessions including 43 landraces and cultivars from the Iberian Peninsula, and 53 landraces collected worldwide. Four subpopulations were identified. Most Iberian Peninsula accessions clustered together with those from other southern European and northern African countries. Only one accession belonged to another subpopulation, while two accessions were 'admixed'. A lower genetic diversity level was found in the Iberian Peninsula accessions compared to worldwide cowpeas. CONCLUSIONS: The genetic analyses performed in this study brought some insights into worldwide genetic diversity and structure and possible dispersion routes of cultivated cowpea. Also, it provided an in-depth analysis of genetic diversity in Iberian Peninsula cowpeas that will help guide crossing strategies in breeding programs.

Morphological and behavioral responses of zebrafish after 24h of ketamine embryonic exposure.

Ketamine, one anesthetic used as an illicit drug, has been detected both in freshwater and marine ecosystems. However, knowledge of its impact on aquatic life is still limited. This study aimed to test its effects in zebrafish embryos by analyzing its time- and dose-dependent developmental toxicity and long-term behavioral changes. The 24h-LC50 was calculated from percent survival using probit analysis. Based on the 24h-LC50 (94.4mgL-1), embryos (2hour post-fertilization - hpf) were divided into four groups, including control, and exposed for 24h to ketamine concentrations of 50, 70 or 90mgL-1. Developmental parameters were evaluated on the course of the experimental period, and anatomical abnormalities and locomotor deficits were analyzed at 144hpf. Although the portion of ketamine transferred into the embryo was higher in the lowest exposed group (about 0.056±0.020pmol per embryo), the results showed that endpoints such as increased mortality, edema, heart rate alterations, malformation and abnormal growth rates were significantly affected. At 144hpf, the developmental abnormalities included thoracic and trunk abnormalities in the groups exposed to 70 and 90mgL-1. Defects in cartilage (alcian blue) and bone (calcein) elements also corroborated the craniofacial anomalies observed. A significant up-regulation of the development-related gene nog3 was detected by qRT-PCR at 8 hpf. Early exposure to ketamine also resulted in long-term behavioral changes, such as an increase in thigmotaxis and disruption of avoidance behavior at 144 hpf. Altogether, this study provides new evidence on the ketamine teratogenic potential, indicating a possible pharmacological impact of ketamine in aquatic environments.

European cowpea landraces for a more sustainable agriculture system and novel foods.

BACKGROUND: Genetic diversity is fundamental to breeding programs and consequently has an important role in obtaining new varieties. To properly use the genetic diversity present in germplasm collections, a good knowledge of the agro-morphological traits of each accession is needed. The aim of this study was to explore the production capacity of 24 cowpea landraces from southern Europe, through phenotypic characterization and evaluation in three different locations in Greece and Portugal. RESULTS: Most qualitative parameters tested showed a high stability among the three locations. A wide difference was observed among the three locations with respect to number of days to flowering, ranging from 55 to 99 days. Quantitative traits showed a higher genotype × environment than genetic variance component. In general, an inverse relationship between σ2ge /σ2g ratio (where σ2ge is genotype × genotype interaction and σ2g is genotype impact) and heritability value was observed. Principal component analysis was able to group accessions based on their origin. The first two principal components explained 97.52% of variation, being the number of seeds per plant, plant height and seed protein content, the traits which contributed most to variability. CONCLUSION: The results show that sufficient variation exists in different traits within landraces in the studied cowpea germplasm to pursue a breeding program. However, the quantitative traits showed a higher genotype × environment component. © 2017 Society of Chemical Industry.

Embryonic Stage-Dependent Teratogenicity of Ketamine in Zebrafish (Danio rerio).

Ketamine, a widely used anesthetic, has been shown to have NMDA receptor dependent and independent actions during zebrafish (Danio rerio) embryogenesis. Notwithstanding, the effects of developmental toxicity and the mechanisms of ketamine action on fish embryos are still not well understood, and its implications for early vertebrate development remains to be clarified. In this work, zebrafish embryos were exposed to ketamine (0.2, 0.4, and 0.8 mg mL(-1)) in order to study the stage-developmental toxicity of this pharmaceutical. During 256-cell (2.5 h post-fertilization, hpf), 50% epiboly (5.5 hpf) and 1-4 somites (10.5 hpf), embryos were exposed to the referred ketamine concentrations for a period of 20 min and were allowed to grow until 144 hpf. Both lethal and nonlethal parameters were evaluated. Skeletal development was assessed by alcian blue and calcein staining. Additionally, the expression of the developmental genes sonic hedgehog a (shh a) and noggin 3 (nog3) was evaluated. Similar to our previous work, bone and cartilage malformations were observed after 256-cell exposure. During 50% epiboly, ketamine exposure induced concentration-dependent mortality and malformations, such as lordosis and/or kyphosis and microcephaly, namely, at higher concentrations. Conversely, exposure during 1-4 somites showed the induction of nonspecific effects with no rise in mortality. The quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed differences in shh a and nog3 expressions comparatively to the control group. Overall, this study shows that the ketamine toxic profile is developmental phase-dependent with 256-cell being the most susceptible phase. The effects observed may result from ketamine interaction with cellular signaling pathways that merits further investigation.

Assessment of the impact of Aluminum on germination, early growth and free proline content in Lactuca sativa L.

Aluminum (Al) toxicity is a major problem in crop production on acid soils. The use of industrial or municipal wastewaters, which may be contaminated with metals, for irrigation in agriculture is common over the world. This action can increase the concentration of these agents in the soil and decrease crops yields. In order to evaluate the toxicological effects of recommended Al levels in irrigation water, under acidic conditions, on lettuce, seeds of two cultivars ("cv Reine de Mai" and "cv White Boston") were exposed to five different Al concentrations (0, 0.05, 0.5, 5 and 20mg/L) and germination percentage, root and shoot lengths were measured. Also, the germination rate and the vigor index were calculated, and the proline content was estimated for all concentrations. Results showed that seed germination was not negatively affected by Al, but the germination rate decreased in both cultivars. For the other factors analyzed, with the exception of 20mg/L concentration for "cv White Boston", Al induced, in general, negative effects including the content of proline that increased in the seeds that were exposed to this metal. The "cv Reine de Mai" was more sensitive for the analyzed concentrations than the other cultivar.. The results indicated that even recommended Al concentrations for irrigation, under acidic conditions, can interfere negatively in seed germination and seedling establishment and possibly with crop production.

Screening and identification of potential sex-associated sequences in Danio rerio.

Current knowledge on zebrafish (Danio rerio) suggests that sex determination has a polygenic genetic basis in this species, although environmental factors may also be involved. This study aimed to identify sex-associated genomic regions using two different marker systems: inter-simple sequence repeats (ISSRs) and random-amplified polymorphic DNA (RAPDs). Two bulks were constructed: one with DNA from zebrafish females and the other from males; then, a total of 100 ISSR and 280 RAPD primers were tested. Three DNA fragments presenting sexual dimorphism (female-linked: OPA17436 and OPQ191027 ; male-linked: OPQ19951 ) were determined from sequential analysis of the bulks followed by assessment in individuals. These fragments were cloned and convert into the following sequenced characterized amplified regions (SCAR): DrSM_F1, DrSM_F2, and DrSM_M, which share identities with sequences located in chromosomes 2, 3, and 11 (Zv9), respectively. Using these potential markers in zebrafish samples it was possible to correctly identify 80% of the males (DrSM_M) and 100% of the females (DrSM_F1 + DrSM_F2) in the analyzed population.

Effects of physical exercise training in DNA damage and repair activity in humans with different genetic polymorphisms of hOGG1 (Ser326Cys).

The main purpose of this pilot study was to investigate the possible influence of genetic polymorphisms of the hOGG1 (Ser326Cys) gene in DNA damage and repair activity by 8-oxoguanine DNA glycosylase 1 (OGG1 enzyme) in response to 16 weeks of combined physical exercise training. Thirty-two healthy Caucasian men (40-74 years old) were enrolled in this study. All the subjects were submitted to a training of 16 weeks of combined physical exercise. The subjects with Ser/Ser genotype were considered as wild-type group (WTG), and Ser/Cys and Cys/Cys genotype were analysed together as mutant group (MG). We used comet assay in conjunction with formamidopyrimidine DNA glycoslyase (FPG) to analyse both strand breaks and FPG-sensitive sites. DNA repair activity were also analysed with the comet assay technique. Our results showed no differences between DNA damage (both strand breaks and FPG-sensitive sites) and repair activity (OGG1) between genotype groups (in the pre-training condition). Regarding the possible influence of genotype in the response to 16 weeks of physical exercise training, the results revealed a decrease in DNA strand breaks in both groups, a decrease in FPG-sensitive sites and an increase in total antioxidant capacity in the WTG, but no changes were found in MG. No significant changes in DNA repair activity was observed in both genotype groups with physical exercise training. This preliminary study suggests the possibility of different responses in DNA damage to the physical exercise training, considering the hOGG1 Ser326Cys polymorphism.

Survey of Mycobacterium avium subspecies paratuberculosis in road-killed wild carnivores in Portugal.

A survey to determine the occurrence of Mycobacterium avium subsp. paratuberculosis (MAP) in wild carnivores in Portugal was conducted by testing samples from road-killed animals between 2009 and 2012. Postmortem examinations were performed and tissues were collected from wild carnivores representing four families and six different species, with a total of 74 animals analyzed. Cultures were performed by using Löwenstein-Jensen and Middlebrook 7H11 solid media and acid-fast isolates were identified by polymerase chain reaction (PCR) and mycobactin dependency characteristics. Tissues were also screened for MAP by directly extracting DNA and testing for the MAP-specific sequences. The occurrence of infected animals (an animal had at least one tissue that was positive for culture or direct PCR) was 27.0% (n = 20). MAP was isolated from culture of 25 tissue samples (3.8%) and was detected by direct PCR in 40 (6.0%) samples. Infection was recorded in 5/6 studied species: 7/49 (14.3%) red foxes (Vulpes vulpes), 3/3 (100%) beech martens (Martes foina), 2/4 (50.0%) Eurasian otters (Lutra lutra), 7/15 (46.7%) Egyptian mongooses (Herpestes ichneumon), and 1/1 (100%) European badger (Meles meles). These species represent three different taxonomic families: Canidae (14.3% were positive), Mustelidae (75.0% were positive), and Herpestidae (46.7% were positive). The results of this study confirm the presence of MAP infection in wild carnivores in Portugal.

Mycobacterium avium subsp. paratuberculosis in Wild Boar (Sus scrofa) in Portugal.

Paratuberculosis, or Johne's disease, caused by Mycobacterium avium subsp. paratuberculosis (MAP), is a chronic granulomatous enteritis affecting both domestic and wild ruminants. The agent was also found in wild mammals such as wild boar (Sus scrofa); however, the role of wild mammals in the epidemiology of MAP is unclear. During the research period, 941 free-ranging wild boar (S. scrofa) legally hunted in two locations in the central-eastern region of Portugal were examined. Ninety-seven wild boars exhibited one or more gross lesions and were tested for the presence of Mycobacterium avium subsp. paratuberculosis using acid-fast staining, mycobacterial culture, polymerase chain reaction (PCR), and histopathological examination. Forty-five animals (46.4%, 95% CI: 36.5-56.3%) were identified as infected, as indicated by positive results in culture and/or PCR. The findings revealed that the most significant risk factor was being a juvenile compared to yearlings and adults (OR = 10.2, 95% CI: 2.2-48.0). Based on our results, 37.9% (n = 11) of the infected animals were considered suitable for human consumption. Our findings offer novel insights into mycobacterial infections in wild boar populations in Portugal and suggest that wild boar could be a source of human infection if zoonotic potential is considered.

Hunting for Answers: Assessing Brucella spp. Seroprevalence and Risks in Red Deer and Wild Boar in Central Portugal.

Between 2016 and 2023, a cross-sectional study was conducted in the central region of Portugal in order to better understand the epidemiology and public health risks resulting from the handling and consumption of game animals infected with Brucella spp. The seroprevalence and risk factors for Brucella spp. seropositivity were evaluated. Antibodies against Brucella spp. were determined using a commercial enzyme-linked immunosorbent assay (ELISA) according to the manufacturer's instructions. Results showed that in the 650 serum samples collected from red deer (n = 298) and wild boars (n = 352) in Portugal, 21.7% (n = 141; 95% CI: 18.6-25.1%) tested positive. Wild boar had a significantly higher prevalence (35.5%; 95% CI: 30.5-40.8%) than red deer (5.4%, 95% CI: 3.1-8.6%; p ≤ 0.001). Risk factors for seropositivity were investigated using multivariable logistic regression models. The odds of being seropositive was 8.39 (95% CI: 4.75-14.84; p ≤ 0.001) times higher in wild boar than in red deer. Correlations between sex, age, body condition, and seropositivity could not be observed. The higher seroprevalence in wild boar suggests that this species may primarily contribute to the Brucella spp. ecology in central Portugal.

Disseminated Mycobacterium avium subsp. paratuberculosis infection in two wild Eurasian otters (Lutra lutra L.) from Portugal.

Disseminated Mycobacterium avium subsp. paratuberculosis (MAP) infections were found in two Eurasian otters (Lutra lutra, L. 1758) killed by vehicular trauma in February and March 2010 in Castelo Branco, Portugal. At postmortem examination, the organs showed no significant gross alterations; however, microscopically, both animals had diffuse lymphadenitis with macrophage infiltration and deposition of hyaline material in the center of the lymphoid follicles. Acid-fast organisms were isolated from gastrointestinal tissue samples via bacteriologic culture. These organisms were identified as M. avium subsp. paratuberculosis by IS900 polymerase chain reaction (PCR). Additionally, direct IS900 PCR-positive results were obtained for multiple organs of both animals. This is the first report of MAP infection of otters in Portugal.

Molecular mechanisms involved in fruit cracking: A review.

Several fleshy fruits are highly affected by cracking, a severe physiological disorder that compromises their quality and causes high economical losses to the producers. Cracking can occur due to physiological, genetic or environmental factors and may happen during fruit growth, development and ripening. Moreover, in fleshy fruits, exocarp plays an important role, acting as a mechanical protective barrier, defending against biotic or abiotic factors. Thus, when biochemical properties of the cuticle + epidermis + hypodermis are affected, cracks appear in the fruit skin. The identification of genes involved in development such as cell wall modifications, biosynthesis and transport of cuticular waxes, cuticular membrane deposition and associated transcription factors provides new insights to better understand how fruit cracking is affected by genetic factors. Amongst the major environmental stresses causing cracking are excessive water during fruit development, leading to imbalances in cations such as Ca. This review focus on expression of key genes in these pathways, in their influence in affected fruits and the potential for molecular breeding programs, aiming to develop cultivars more resistant to cracking under adverse environmental conditions.

First morphological and molecular isolation of Talaromyces marneffei in beech marten (Martes foina) in Portugal.

Talaromyces marneffei is a zoonotic fungus that mostly infects immunocompromised individuals. For the first time, this fungus was isolated in an adult beech marten (Martes foina) hit by a car, found dead in Penamacor, Portugal. During the necropsy, different samples (skin, fur, lymph nodes, lung, spleen, kidneys, and brain) were collected and processed for microbiology (including mycology) and molecular biology. T. marneffei was identified through its mycological characteristics and confirmed by PCR in hair samples. No other lesions or alterations were reported, except a concomitant presence of M. avium subsp. paratuberculosis in lung, kidney and brain samples. To the authors' knowledge, this is the first description of this fungus beech marten, as well as the first case of co-infection with M. avium subsp. paratuberculosis in wildlife fauna. These results suggest a sylvatic life-cycle of T. marneffei, involving beech martens, in Portugal.

Seropositivity for Coxiella burnetii in Wild Boar (Sus scrofa) and Red Deer (Cervus elaphus) in Portugal.

Q fever is caused by the pathogen Coxiella burnetii and is a zoonosis that naturally infects goats, sheep, and cats, but can also infect humans, birds, reptiles, or arthropods. A survey was conducted for the detection of antibodies against C. burnetii in a sample of 617 free-ranging wild ruminants, 358 wild boar (Sus scrofa) and 259 red deer (Cervus elaphus), in east-central Portugal during the 2016-2022 hunting seasons. Only adult animals were sampled in this study. Antibodies specific to C. burnetii were detected using a commercial enzyme-linked immunosorbent assay (ELISA; IDVet®, Montpellier, France) according to the manufacturer's instructions. The seroprevalence of C. burnetii infection was 1.5% (n = 9; 95% confidence interval [CI]: 0.7-2.8%). Antibodies against C. burnetii were detected in 4/358 wild boar (1.1%; 95% CI: CI: 0.3-2.8%) and 5/259 red deer (1.9%; 0.6-4.5%). Results of the present study indicate that antibodies against C. burnetii were present in wild boar and red deer in Portugal. These findings can help local health authorities to focus on the problem of C. burnetii in wildlife and facilitate the application of a One Health approach to its prevention and control.

Prevalence and Risk Factors for Hepatitis E Virus in Wild Boar and Red Deer in Portugal.

Hepatitis E virus (HEV) is a zoonotic foodborne virus with an annual infection prevalence of 20 million human cases, which seriously affects public health and economic development in both developed and developing countries. To better understand the epidemiology of HEV in Central Portugal, a cross-sectional study was conducted from 2016 to 2023 with sera samples from wild ungulates. The seroprevalence and risk factors for HEV seropositivity were evaluated in the present study. Specifically, antibodies against HEV were determined by a commercial enzyme-linked immune-sorbent assay (ELISA). Our results show that in the 650 sera samples collected from 298 wild red deer and 352 wild boars in Portugal, 9.1% red deer and 1.7% wild boar were positive for antibodies to HEV. Regarding age, the seropositivity in juvenile wild ungulates was 1.3%, whereas it was 7.2% in adults. Logistic regression models investigated risk factors for seropositivity. The odds of being seropositive was 3.6 times higher in adults than in juveniles, and the risk was 4.2 times higher in red deer than in wild boar. Both wild ungulate species were exposed to HEV. The higher seroprevalence in red deer suggests that this species may make a major contribution to the ecology of HEV in Central Portugal. Further research is needed to understand how wildlife affects the epidemiology of HEV infections in Portugal.

[Coronary artery anomalies]. / Anomalias das artérias coronárias.

Coronary artery anomalies (CAAs) are a rare entity but their true incidence in the general population has yet to be determined. Most CAAs are asymptomatic, but they are nevertheless the second leading cause of sudden death in apparently healthy young athletes. The new imaging methods available to cardiologists, including CT angiography and MRI, now enable noninvasive diagnosis and characterization of these anomalies. The authors review the literature and present a retrospective study of 360 consecutive patients who underwent cardiac CT angiography. Demographic, clinical and angiographic characteristics were studied. The incidence of CAAs in this population was 2.69%. In order to better characterize this disorder, including diagnostic strategy, screening, treatment and prognosis, the authors suggest the establishment of a national registry of cardiac CT angiography. Such a registry would fill the existing gap in information on exams performed in the country, enriching current knowledge about this disease and noninvasive cardiac imaging in Portugal.

Subcellular compartmentalization of aluminum reduced its hazardous impact on rye photosynthesis.

Aluminum (Al) toxicity limits crops growth and production in acidic soils. Compared to roots, less is known about the toxic effects of Al in leaves. Al subcellular compartmentalization is also largely unknown. Using rye (Secale cereale L.) Beira (more tolerant) and RioDeva (more sensitive to Al) genotypes, we evaluated the patterns of Al accumulation in leaf cell organelles and the photosynthetic and metabolic changes to cope with Al toxicity. The tolerant genotype accumulated less Al in all organelles, except the vacuoles. This suggests that Al compartmentalization plays a role in Al tolerance of Beira genotype. PSII efficiency, stomatal conductance, pigment biosynthesis, and photosynthesis metabolism were less affected in the tolerant genotype. In the Calvin cycle, carboxylation was compromised by Al exposure in the tolerant genotype. Other Calvin cycle-related enzymes, phoshoglycerate kinase (PGK), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), triose-phosphate isomerase (TPI), and fructose 1,6-bisphosphatase (FBPase) activities decreased in the sensitive line after 48 h of Al exposure. Consequentially, carbohydrate and organic acid metabolism were affected in a genotype-specific manner, where sugar levels increased only in the tolerant genotype. In conclusion, Al transport to the leaf and compartmentalization in the vacuoles tolerant genotype's leaf cells provide complementary mechanisms of Al tolerance, protecting the photosynthetic apparatus and thereby sustaining growth.

Al exposure increases proline levels by different pathways in an Al-sensitive and an Al-tolerant rye genotype.

Aluminium (Al) toxicity limits crop productivity, particularly at low soil pH. Proline (Pro) plays a role in protecting plants against various abiotic stresses. Using the relatively Al-tolerant cereal rye (Secale cereale L.), we evaluated Pro metabolism in roots and shoots of two genotypes differing in Al tolerance, var. RioDeva (sensitive) and var. Beira (tolerant). Most enzyme activities and metabolites of Pro biosynthesis were analysed. Al induced increases in Pro levels in each genotype, but the mechanisms were different and were also different between roots and shoots. The Al-tolerant genotype accumulated highest Pro levels and this stronger increase was ascribed to simultaneous activation of the ornithine (Orn)-biosynthetic pathway and decrease in Pro oxidation. The Orn pathway was particularly enhanced in roots. Nitrate reductase (NR) activity, N levels, and N/C ratios demonstrate that N-metabolism is less inhibited in the Al-tolerant line. The correlation between Pro changes and differences in Al-sensitivity between these two genotypes, supports a role for Pro in Al tolerance. Our results suggest that differential responses in Pro biosynthesis may be linked to N-availability. Understanding the role of Pro in differences between genotypes in stress responses, could be valuable in plant selection and breeding for Al resistance.