Rootstock Effects on Leaf Photosynthesis in 'Navelina' Trees Grown in Calcareous Soil

Citrus crops in the Mediterranean region are often grown in high pH calcareous soils, which promote nutrient imbalances, especially iron deficiency. 'Navelina' trees grafted on eight different citrus rootstocks were assessed in terms of their relative tolerance to these soils. To do so, leaf gas exchange and chlorophyll a fluorescence parameters were measured for 2 consecutive years in leaves without visible injury symptoms. Trees were grown on the rootstocks Carrizo citrange, hybrids of Cleopatra mandarin x Poncirus trifoliata no. 5 (F-A 5),13 (F-A 13), and 16 (030116), Troyer citrange x common mandarin no. 18 (F-A 418), King mandarin x P. trifoliata no. 7 (F-A 517), 020324 (Troyer citrange x Cleopatra mandarin), and Volkamer lemon x P. trifoliata no. 64 (230164). gs and transpiration rate were clearly lower in leaves of shoots grafted on Carrizo citrange than in those on the other rootstocks assayed, but net photosynthetic flux did not differ. However, leaves of shoots on Carrizo citrange displayed a decline in their maximum quantum yield of PSII photochemistry [variable fluorescence/maximum fluorescence (F(v)/F(m)) ratio] and other chlorophyll parameters in the steady state such as photochemical quenching (qp) and the quantum efficiency of PSII photochemistry as well as an increase in nonphotochemical quenching (q(N)). Other rootstocks such as 030116, F-A 517 and, especially, F-A 5 showed the highest Phi(PSU) and F(v)/F(m) values, whereas F-A 5 had the lowest qN in the steady state. The photosynthetic characteristics observed in leaves on Carrizo citrange showed them to be the least tolerant to these calcareous conditions, whereas photosynthesis of 'Navelina' trees budded on F-A 5 were the most tolerant

Differential gene expression analysis provides new insights into the molecular basis of iron deficiency stress response in the citrus rootstock Poncirus trifoliata (L.) Raf.

Iron chlorosis is one of the major abiotic stresses affecting fruit trees and other crops in calcareous soils and leads to a reduction in growth and yield. Usual remediation strategies consist of amending iron to soil, which is an expensive practice, or using tolerant cultivars, which are difficult to develop when not available. To understand the mechanisms underlying the associated physiopathy better, and thus develop new strategies to overcome the problems resulting from iron deficiency, the differential gene expression induced by iron deficiency in the susceptible citrus rootstock Poncirus trifoliata (L.) Raf. have been examined. The genes identified are putatively involved in cell wall modification, in determining photosynthesis rate and chlorophyll content, and reducing oxidative stress. Additional studies on cell wall morphology, photosynthesis, and chlorophyll content, as well as peroxidase and catalase activities, support their possible functions in the response to iron deficiency in a susceptible genotype, and the results are discussed

Clinical evaluation of antiseptic mouth rinses to reduce salivary load of SARS-CoV-2

Most public health measures to contain the COVID-19 pandemic are based on preventing the pathogen spread, and the use of oral antiseptics has been proposed as a strategy to reduce transmission risk. The aim of this manuscript is to test the efficacy of mouthwashes to reduce salivary viral load in vivo. This is a multi-centre, blinded, parallel-group, placebo-controlled randomised clinical trial that tests the effect of four mouthwashes (cetylpyridinium chloride, chlorhexidine, povidone-iodine and hydrogen peroxide) in SARS-CoV-2 salivary load measured by qPCR at baseline and 30, 60 and 120 min after the mouthrinse. A fifth group of patients used distilled water mouthrinse as a control. Eighty-four participants were recruited and divided into 12-15 per group. There were no statistically significant changes in salivary viral load after the use of the different mouthwashes. Although oral antiseptics have shown virucidal effects in vitro, our data show that salivary viral load in COVID-19 patients was not affected by the tested treatments. This could reflect that those mouthwashes are not effective in vivo, or that viral particles are not infective but viral RNA is still detected by PCR. Viral infectivity studies after the use of mouthwashes are therefore required

Current clinical spectrum of common variable immunodeficiency in Spain: The multicentric nationwide GTEM-SEMI-CVID registry

Common variable immunodeficiency (CVID) constitutes a heterogenic group of primary immunodeficiency disorders with a wide-ranging clinical spectrum. CVID-associated non-infectious morbidity constitutes a major challenge requiring a full understanding of its pathophysiology and its clinical importance and global variability, especially considering the broad clinical, genetic, and regional heterogeneity of CVID disorders. This work aimed to develop a nationwide, multicenter, retrospective study over a 3-year period describing epidemiological, clinical, laboratory, therapeutic, and prognostic features of 250 CVID patients in Spain. The mean diagnostic delay was around 10 years and most patients initially presented with infectious complications followed by non-infectious immune disorders. However, infectious diseases were not the main cause of morbimortality. Non-infectious lung disease was extraordinarily frequent in our registry affecting approximately 60% of the patients. More than one-third of the patients in our cohort showed lymphadenopathies and splenomegaly in their follow-up, and more than 33% presented immune cytopenias, especially Evans' syndrome. Gastrointestinal disease was observed in more than 40% of the patients. Among biopsied organs in our cohort, benign lymphoproliferation was the principal histopathological alteration. Reaching 15.26%, the global prevalence of cancer in our registry was one of the highest reported to date, with non-Hodgkin B lymphoma being the most frequent. These data emphasize the importance of basic and translational research delving into the pathophysiological pathways involved in immune dysregulation and diffuse lymphocytic infiltration. This would reveal new tailored strategies to reduce immune complications, and the associated healthcare burden, and ensure a better quality of life for CVID patients

Safety and immunogenicity of the protein-based PHH-1V compared to BNT162b2 as a heterologous SARS-CoV-2 booster vaccine in adults vaccinated against COVID-19 : a multicentre, randomised, double-blind, non-inferiority phase IIb trial

A SARS-CoV-2 protein-based heterodimer vaccine, PHH-1V, has been shown to be safe and well-tolerated in healthy young adults in a first-in-human, Phase I/IIa study dose-escalation trial. Here, we report the interim results of the Phase IIb HH-2, where the immunogenicity and safety of a heterologous booster with PHH-1V is assessed versus a homologous booster with BNT162b2 at 14, 28 and 98 days after vaccine administration. The HH-2 study is an ongoing multicentre, randomised, active-controlled, double-blind, non-inferiority Phase IIb trial, where participants 18 years or older who had received two doses of BNT162b2 were randomly assigned in a 2:1 ratio to receive a booster dose of vaccine-either heterologous (PHH-1V group) or homologous (BNT162b2 group)-in 10 centres in Spain. Eligible subjects were allocated to treatment stratified by age group (18-64 versus ≥65 years) with approximately 10% of the sample enrolled in the older age group. The primary endpoints were humoral immunogenicity measured by changes in levels of neutralizing antibodies (PBNA) against the ancestral Wuhan-Hu-1 strain after the PHH-1V or the BNT162b2 boost, and the safety and tolerability of PHH-1V as a boost. The secondary endpoints were to compare changes in levels of neutralizing antibodies against different variants of SARS-CoV-2 and the T-cell responses towards the SARS-CoV-2 spike glycoprotein peptides. The exploratory endpoint was to assess the number of subjects with SARS-CoV-2 infections ≥14 days after PHH-1V booster. This study is ongoing and is registered with , . From 15 November 2021, 782 adults were randomly assigned to PHH-1V (n = 522) or BNT162b2 (n = 260) boost vaccine groups. The geometric mean titre (GMT) ratio of neutralizing antibodies on days 14, 28 and 98, shown as BNT162b2 active control versus PHH-1V, was, respectively, 1.68 (p < 0.0001), 1.31 (p = 0.0007) and 0.86 (p = 0.40) for the ancestral Wuhan-Hu-1 strain; 0.62 (p < 0.0001), 0.65 (p < 0.0001) and 0.56 (p = 0.003) for the Beta variant; 1.01 (p = 0.92), 0.88 (p = 0.11) and 0.52 (p = 0.0003) for the Delta variant; and 0.59 (p ≤ 0.0001), 0.66 (p < 0.0001) and 0.57 (p = 0.0028) for the Omicron BA.1 variant. Additionally, PHH-1V as a booster dose induced a significant increase of CD4 + and CD8 + T-cells expressing IFN-γ on day 14. There were 458 participants who experienced at least one adverse event (89.3%) in the PHH-1V and 238 (94.4%) in the BNT162b2 group. The most frequent adverse events were injection site pain (79.7% and 89.3%), fatigue (27.5% and 42.1%) and headache (31.2 and 40.1%) for the PHH-1V and the BNT162b2 groups, respectively. A total of 52 COVID-19 cases occurred from day 14 post-vaccination (10.14%) for the PHH-1V group and 30 (11.90%) for the BNT162b2 group (p = 0.45), and none of the subjects developed severe COVID-19. Our interim results from the Phase IIb HH-2 trial show that PHH-1V as a heterologous booster vaccine, when compared to BNT162b2, although it does not reach a non-inferior neutralizing antibody response against the Wuhan-Hu-1 strain at days 14 and 28 after vaccination, it does so at day 98. PHH-1V as a heterologous booster elicits a superior neutralizing antibody response against the previous circulating Beta and the currently circulating Omicron BA.1 SARS-CoV-2 variants in all time points assessed, and for the Delta variant on day 98 as well. Moreover, the PHH-1V boost also induces a strong and balanced T-cell response. Concerning the safety profile, subjects in the PHH-1V group report significantly fewer adverse events than those in the BNT162b2 group, most of mild intensity, and both vaccine groups present comparable COVID-19 breakthrough cases, none of them severe. HIPRA SCIENTIFIC, S.L.U

Rootstock Effects on Leaf Photosynthesis in ‘Navelina’ Trees Grown in Calcareous Soil

Citrus crops in the Mediterranean region are often grown in high pH calcareous soils, which promote nutrient imbalances, especially iron deficiency. &#39;Navelina&#39; trees grafted on eight different citrus rootstocks were assessed in terms of their relative tolerance to these soils. To do so, leaf gas exchange and chlorophyll a fluorescence parameters were measured for 2 consecutive years in leaves without visible injury symptoms. Trees were grown on the rootstocks Carrizo citrange, hybrids of Cleopatra mandarin x Poncirus trifoliata no. 5 (F-A 5),13 (F-A 13), and 16 (030116), Troyer citrange x common mandarin no. 18 (F-A 418), King mandarin x P. trifoliata no. 7 (F-A 517), 020324 (Troyer citrange x Cleopatra mandarin), and Volkamer lemon x P. trifoliata no. 64 (230164). gs and transpiration rate were clearly lower in leaves of shoots grafted on Carrizo citrange than in those on the other rootstocks assayed, but net photosynthetic flux did not differ. However, leaves of shoots on Carrizo citrange displayed a decline in their maximum quantum yield of PSII photochemistry [variable fluorescence/maximum fluorescence (F(v)/F(m)) ratio] and other chlorophyll parameters in the steady state such as photochemical quenching (qp) and the quantum efficiency of PSII photochemistry as well as an increase in nonphotochemical quenching (q(N)). Other rootstocks such as 030116, F-A 517 and, especially, F-A 5 showed the highest Phi(PSU) and F(v)/F(m) values, whereas F-A 5 had the lowest qN in the steady state. The photosynthetic characteristics observed in leaves on Carrizo citrange showed them to be the least tolerant to these calcareous conditions, whereas photosynthesis of &#39;Navelina&#39; trees budded on F-A 5 were the most tolerant

Performance of 'Clausellina' mandarin on four rootstocks

This study, carried out in Almeria (Spain), evaluates the performance of &#39;Clausellina&#39; mandarin on four rootstocks: Carrizo citrange [Citrus sinensis (L.) Osb. x Poncirus trifoliata (L.) Raft C. volkameriana Ten. and Pasq.; and, the two new hybrids &#39;C-13&#39; (C. depressa Hay. x P trifoliata) obtained at the University of California Citrus Research Center and &#39;020326&#39; [Troyer citrange (C. sinensis x P trifoliata) x Cleopatra mandarin] obtained at the Instituto Valenciano de Investigaciones Agrarias in Valencia (Spain). Soil was sandy, with pH&gt;8 and electric conductivity below 4.5 mmhos cm(-1) in the saturation extract. Yield was weighed during the first nine harvests, fruit quality was determined in the 5(th) and 9(th) harvests and tree size was evaluated annually from 3 to 11 years after planting. Trees on C. volkameriana rootstock were biggest and produced the highest yield, followed by trees on Carrizo citrange. Trees on the C-13 hybrid selection were most efficient in yield m(-3) of canopy volume. There were few differences between rootstocks in terms of fruit quality

The Citrus Rootstocks Cleopatra Mandarin, Poncirus trifoliata, Forner-Alcaide 5 and Forner-Alcaide 13 Vary in Susceptibility to Iron Deficiency Chlorosis

We have studied tolerance to iron chlorosis of four citrus seedling rootstocks: the two hybrids Forner-Alcaide 5 (F-A 5) and Forner-Alcaide 13 (F-A 13), as well as their parents [Cleoptra mandarin (Citrus reshni Hort. ex Tan.) and Poncirus trifoliata (L.) Raf.]. Six-month-old potted plants were grown in four different iron concentrations (0, 9, 18 and 36 square M) and leaf iron content, dry weight, total chlorophyll content, catalase activity and root ferric chelate reductase (FCR) activity were measured after 60 days. F-A 5 had the highest FCR activity, total chlorophyll content, total dry weight and iron content in roots. P. trifoliata, a genus susceptible to iron chlorosis, showed the lowest total chlorophyll content, FCR activity and total dry weight. F-A 5 is an iron-chlorosis-tolerant rootstock which may be suitable for use in soils that cause this problem