A Novel Single-Site Mutation in the Catalytic Domain of Protoporphyrinogen Oxidase IX (PPO) Confers Resistance to PPO-Inhibiting Herbicides

Protoporphyrinogen oxidase (PPO)-inhibiting herbicides are used to control weeds in a variety of crops. These herbicides inhibit heme and photosynthesis in plants. PPO-inhibiting herbicides are used to control Amaranthus palmeri (Palmer amaranth) especially those with resistance to glyphosate and acetolactate synthase (ALS) inhibiting herbicides. While investigating the basis of high fomesafen-resistance in A. palmeri, we identified a new amino acid substitution of glycine to alanine in the catalytic domain of PPO2 at position 399 (G399A) (numbered according to the protein sequence of A. palmeri). G399 is highly conserved in the PPO protein family across eukaryotic species. Through combined molecular, computational, and biochemical approaches, we established that PPO2 with G399A mutation has reduced affinity for several PPO-inhibiting herbicides, possibly due to steric hindrance induced by the mutation. This is the first report of a PPO2 amino acid substitution at G399 position in a field-selected weed population of A. palmeri. The mutant A. palmeri PPO2 showed high-level in vitro resistance to different PPO inhibitors relative to the wild type. The G399A mutation is very likely to confer resistance to other weed species under selection imposed by the extensive agricultural use of PPO-inhibiting herbicides

Field-Evolved <i>ΔG210-ppo2</i> from Palmer Amaranth Confers Pre-emergence Tolerance to PPO-Inhibitors in Rice and <i>Arabidopsis</i>

Resistance to protoporphyrinogen IX oxidase (PPO)-inhibitors in Amaranthus palmeri and Amaranthus tuberculatus is mainly contributed by mutations in the PPO enzyme, which renders herbicide molecules ineffective. The deletion of glycine210 (ΔG210) is the most predominant PPO mutation. ΔG210-ppo2 is overexpressed in rice (Oryza sativa c. ‘Nipponbare’) and Arabidopsis thaliana (Col-0). A foliar assay was conducted on transgenic T1 rice plants with 2× dose of fomesafen (780 g ha−1), showing less injury than the non-transgenic (WT) plants. A soil-based assay conducted with T2 rice seeds confirmed tolerance to fomesafen applied pre-emergence. In agar medium, root growth of WT rice seedlings was inhibited >90% at 5 µM fomesafen, while root growth of T2 seedlings was inhibited by 50% at 45 µM fomesafen. The presence and expression of the transgene were confirmed in the T2 rice survivors of soil-applied fomesafen. A soil-based assay was also conducted with transgenic A. thaliana expressing ΔG210-ppo2 which confirmed tolerance to the pre-emergence application of fomesafen and saflufenacil. The expression of A. palmeri ΔG210-ppo2 successfully conferred tolerance to soil-applied fomesafen in rice and Arabidopsis. This mutant also confers cross-tolerance to saflufenacil in Arabidopsis. This trait could be introduced into high-value crops that lack chemical options for weed management

The ISTH bleeding assessment tool as predictor of bleeding events in inherited platelet disorders: Communication from the ISTH SSC Subcommittee on Platelet Physiology

International audienceBackground The ISTH Bleeding Assessment Tool (ISTH-BAT) has been validated for clinical screening of suspected von Willebrand disease (VWD) and for bleeding prediction. Recently it has been validated for subjects with inherited platelet disorders (IPD) (BAT-VAL study).Objectives To determine whether the ISTH-BAT bleeding score (BS) predicts subsequent bleeding events requiring treatment in IPD patients.Methods Patients with IPD, type 1 VWD (VWD-1) and age- and sex-matched healthy controls enrolled in the BAT-VAL study were prospectively followed-up for 2 years and bleeding episodes requiring treatment were recorded.Results Of the 1098 subjects initially enrolled, 955 were followed-up and 124 suffered hemorrhages during follow-up, 60% of whom had inherited platelet function disorders (IPFD). Total number of events was significantly higher in IPFD (n = 235) than VWD-1 (n = 52) or inherited thrombocytopenia (IT; n = 20). Events requiring transfusions were 66% in IPFD, 5.7% in VWD-1, and 3% in IT. Baseline BS was significantly higher in IPFD patients with a bleeding event at follow-up than in those without (p < .01) and the percentage of subjects suffering a bleeding event increased proportionally to baseline BS quartile. A significant association between the BS and the chance of suffering severe bleeding was found in the overall, IPFD, and VWD-1 populations. Similar results were obtained for the pediatric population.Conclusions Inherited platelet function disorder patients with high BS at enrollment are more likely to suffer from bleeding events requiring treatment at follow-up. Moreover, the higher the baseline BS quartile the greater the incidence of subsequent events, suggesting that independently from diagnosis a high BS is associated with a greater risk of subsequent hemorrhage

Validation of the ISTH/SSC bleeding assessment tool for inherited platelet disorders: a communication from the Platelet Physiology SSC

Background: Careful assessment of bleeding history is the first step in the evaluation of patients with mild/moderate bleeding disorders, and the use of a bleeding assessment tool (BAT) is strongly encouraged. Although a few studies have assessed the utility of the ISTH-BAT in patients with inherited platelet function disorders (IPFD) none of them was sufficiently large to draw conclusions and/or included appropriate control groups. Objectives: The aim of the present study was to test the utility of the ISTH-BAT in a large cohort of patients with a well-defined diagnosis of inherited platelets disorder in comparison with two parallel cohorts, one of patients with type-1 von Willebrand disease (VWD-1) and one of healthy controls (HC). Patients/Methods: We enrolled 1098 subjects, 482 of whom had inherited platelet disorders (196 IPFD and 286 inherited platelet number disorders [IT]) from 17 countries. Results: IPFD patients had significantly higher bleeding score (BS; median 9) than VWD-1 patients (median 5), a higher number of hemorrhagic symptoms (4 versus 3), and higher percentage of patients with clinically relevant symptoms (score > 2). The ISTH-BAT showed excellent discrimination power between IPFD and HC (0.9 < area under the curve [AUC] < 1), moderate (0.7 < AUC < 0.9) between IPFD and VWD-1 and between IPFD and inherited thrombocytopenia (IT), while it was inaccurate (AUC ≤ 0.7) in discriminating IT from HC. Conclusions: The ISTH-BAT allows to efficiently discriminate IPFD from HC, while it has lower accuracy in distinguishing IPFD from VWD-1. Therefore, the ISTH-BAT appears useful for identifying subjects requiring laboratory evaluation for a suspected IPFD once VWD is preliminarily excluded.Fil: Gresele, Paolo. Università di Perugia; ItaliaFil: Orsini, Sara. Università di Perugia; ItaliaFil: Noris, Patrizia. Istituto Nazionale di Ricovero e Cura a Carattere Scientifico "Saverio de Bellis"; Italia. Universita Degli Studi Di Pavia; ItaliaFil: Falcinelli, Emanuela. Università di Perugia; ItaliaFil: Alessi, Marie Christine. Centre For Cardiovascular And Nutrition Research; FranciaFil: Bury, Loredana. Università di Perugia; ItaliaFil: Borhany, Munira. No especifíca;Fil: Santoro, Cristina. Azienda Ospedaliera Universitaria Policlinico Umberto I; ItaliaFil: Glembotsky, Ana Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Cid, Ana Rosa. Hospital Universitario y Politecnico La Fe; EspañaFil: Tosetto, Alberto. No especifíca;Fil: De Candia, Erica. Fondazione Policlinico Agostino Gemelli; Italia. Università Cattolica del Sacro Cuore; ItaliaFil: Fontana, Pierre. University Hospitals of Geneva; SuizaFil: Guglielmini, Giuseppe. Università di Perugia; ItaliaFil: Pecci, Alessandro. Universita Degli Studi Di Pavia; ItaliaFil: Heller, Paula Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Médicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Rodorigo, Giuseppina. Istituto Nazionale di Ricovero e Cura a Carattere Scientifico "Saverio de Bellis"; ItaliaFil: Lammle, Bernhard. Università di Perugia; ItaliaFil: Trinchero, Alice. Università di Perugia; ItaliaFil: Paolo, Radossi. Istituto Nazionale di Ricovero e Cura a Carattere Scientifico "Saverio de Bellis"; ItaliaFil: Ferrari, Silvia. Istituto Nazionale di Ricovero e Cura a Carattere Scientifico "Saverio de Bellis"; ItaliaFil: Rancitelli, Davide. Università di Perugia; ItaliaFil: Stolinski, Amy. Università di Perugia; ItaliaFil: Arulselvan, Abinaya. Università di Perugia; ItaliaFil: Lassandro, Giuseppe. Università di Perugia; ItaliaFil: Sánchez Luceros, Analía Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Jandrot Perrus, Martine. Università di Perugia; ItaliaFil: Kunishima, Shinji. Università di Perugia; ItaliaFil: Rivera Pozo, José. Universidad de Murcia; EspañaFil: Lordkipanidzé, Marie. Università di Perugia; ItaliaFil: Melazzini, Federica. Istituto Nazionale di Ricovero e Cura a Carattere Scientifico "Saverio de Bellis"; ItaliaFil: Falaise, Céline. Istituto Nazionale di Ricovero e Cura a Carattere Scientifico "Saverio de Bellis"; ItaliaFil: Casonato, Alessandra. Istituto Nazionale di Ricovero e Cura a Carattere Scientifico "Saverio de Bellis"; ItaliaFil: Podda, Gianmarco. Università di Perugia; ItaliaFil: Kannan, Meganathan. Università di Perugia; ItaliaFil: Jurk, Kerstin. Università di Perugia; ItaliaFil: Sevivas, Teresa. Università di Perugia; ItaliaFil: Castaman, Giancarlo. Universidad de Bologna; ItaliaFil: Grandone, Elvira. Università di Perugia; ItaliaFil: Fiore, Mathieu. Università di Perugia; ItaliaFil: Zuniga, Pamela. Università di Perugia; ItaliaFil: Henskens, Yvonne. Università di Perugia; ItaliaFil: Miyazaki, Koji. Università di Perugia; ItaliaFil: Dupuis, Arnaud. Università di Perugia; ItaliaFil: Hayward, Catherine. Università di Perugia; ItaliaFil: Zaninetti, Carlo. Istituto Nazionale di Ricovero e Cura a Carattere Scientifico "Saverio de Bellis"; ItaliaFil: Abid, Madiha. Università di Perugia; ItaliaFil: Ferrara, Grazia. Università di Perugia; ItaliaFil: Mazzucconi, Maria Gabriella. Università di Perugia; ItaliaFil: Tagariello, Giuseppe. Università di Perugia; ItaliaFil: James, Paula. Università di Perugia; ItaliaFil: Fabris, Fabrizio. Universidad de Bologna; ItaliaFil: Russo, Alexandra. Università di Perugia; ItaliaFil: Bermejo, Nuria. Hospital de San Pedro de Alcantara, Cáceres; EspañaFil: Napolitano, Mariasanta. Università di Perugia; ItaliaFil: Curnow, Jennifer. Università di Perugia; ItaliaFil: Vasiliki, Gkalea. Università di Perugia; ItaliaFil: Zieger, Barbara. Università di Perugia; ItaliaFil: Fedor, Marian. Università di Perugia; ItaliaFil: Chitlur, Meera. Università di Perugia; ItaliaFil: Lambert, Michele. Università di Perugia; ItaliaFil: Barcella, Luca. Università di Perugia; ItaliaFil: Cosmi, Benilde. Università di Perugia; ItaliaFil: Giordano, Paola. Università di Perugia; ItaliaFil: Porri, Claudia. Università di Perugia; ItaliaFil: Eker, Ibrahim. Università di Perugia; ItaliaFil: Morel Kopp, Marie Christine. Università di Perugia; ItaliaFil: Deckmyn, Hans. Università di Perugia; ItaliaFil: Frelinger, Andrew L.. Università di Perugia; ItaliaFil: Harrison, Paul. Università di Perugia; ItaliaFil: Mezzano, Diego. Pontificia Universidad Católica de Chile; ChileFil: Mumford, Andrew D.. University of Bristol; Reino Unid

Validation of the ISTH/SSC bleeding assessment tool for inherited platelet disorders: A communication from the Platelet Physiology SSC

BACKGROUND: Careful assessment of bleeding history is the first step in the evaluation of patients with mild/moderate bleeding disorders, and the use of a bleeding assessment tool (BAT) is strongly encouraged. Although a few studies have assessed the utility of the ISTH-BAT in patients with inherited platelet function disorders (IPFD) none of them was sufficiently large to draw conclusions and/or included appropriate control groups. OBJECTIVES: The aim of the present study was to test the utility of the ISTH-BAT in a large cohort of patients with a well-defined diagnosis of inherited platelets disorder in comparison with two parallel cohorts, one of patients with type-1 von Willebrand disease (VWD-1) and one of healthy controls (HC). PATIENTS/METHODS: We enrolled 1098 subjects, 482 of whom had inherited platelet disorders (196 IPFD and 286 inherited platelet number disorders [IT]) from 17 countries. RESULTS: IPFD patients had significantly higher bleeding score (BS; median 9) than VWD-1 patients (median 5), a higher number of hemorrhagic symptoms (4 versus 3), and higher percentage of patients with clinically relevant symptoms (score > 2). The ISTH-BAT showed excellent discrimination power between IPFD and HC (0.9 < area under the curve [AUC] < 1), moderate (0.7 < AUC < 0.9) between IPFD and VWD-1 and between IPFD and inherited thrombocytopenia (IT), while it was inaccurate (AUC ≤ 0.7) in discriminating IT from HC. CONCLUSIONS: The ISTH-BAT allows to efficiently discriminate IPFD from HC, while it has lower accuracy in distinguishing IPFD from VWD-1. Therefore, the ISTH-BAT appears useful for identifying subjects requiring laboratory evaluation for a suspected IPFD once VWD is preliminarily excluded.status: publishe