13 research outputs found

    Functional stacking of three resistance genes against Phytophthora infestans in potato

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    Functional stacking of broad spectrum resistance (R) genes could potentially be an effective strategy for more durable disease resistance, for example, to potato late blight caused by Phytophthora infestans (Pi). For this reason, three broad spectrum potato R genes (Rpi), Rpi-sto1 (Solanum stoloniferum), Rpi-vnt1.1 (S. venturii) and Rpi-blb3 (S. bulbocastanum) were selected, combined into a single binary vector pBINPLUS and transformed into the susceptible cultivar Desiree. Among the 550 kanamycin resistant regenerants, 28 were further investigated by gene specific PCRs. All regenerants were positive for the nptII gene and 23 of them contained the three Rpi genes, referred to as triple Rpi gene transformants. Detached leaf assay and agro-infiltration of avirulence (Avr) genes showed that the 23 triple Rpi gene transformants were resistant to the selected isolates and showed HR with the three Avr effectors indicating functional stacking of all the three Rpi genes. It is concluded that Avr genes, corresponding to the R genes to be stacked, must be available in order to assay for functionality of each stack component. No indications were found for silencing or any other negative effects affecting the function of the inserted Rpi genes. The resistance spectrum of these 23 triple Rpi gene transformants was, as expected, a sum of the spectra from the three individual Rpi genes. This is the first example of a one-step approach for the simultaneous domestication of three natural R genes against a single disease by genetic transformation

    Effector Genomics Accelerates Discovery and Functional Profiling of Potato Disease Resistance and Phytophthora Infestans Avirulence Genes

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    Potato is the world's fourth largest food crop yet it continues to endure late blight, a devastating disease caused by the Irish famine pathogen Phytophthora infestans. Breeding broad-spectrum disease resistance (R) genes into potato (Solanum tuberosum) is the best strategy for genetically managing late blight but current approaches are slow and inefficient. We used a repertoire of effector genes predicted computationally from the P. infestans genome to accelerate the identification, functional characterization, and cloning of potentially broad-spectrum R genes. An initial set of 54 effectors containing a signal peptide and a RXLR motif was profiled for activation of innate immunity (avirulence or Avr activity) on wild Solanum species and tentative Avr candidates were identified. The RXLR effector family IpiO induced hypersensitive responses (HR) in S. stoloniferum, S. papita and the more distantly related S. bulbocastanum, the source of the R gene Rpi-blb1. Genetic studies with S. stoloniferum showed cosegregation of resistance to P. infestans and response to IpiO. Transient co-expression of IpiO with Rpi-blb1 in a heterologous Nicotiana benthamiana system identified IpiO as Avr-blb1. A candidate gene approach led to the rapid cloning of S. stoloniferum Rpi-sto1 and S. papita Rpi-pta1, which are functionally equivalent to Rpi-blb1. Our findings indicate that effector genomics enables discovery and functional profiling of late blight R genes and Avr genes at an unprecedented rate and promises to accelerate the engineering of late blight resistant potato varieties

    Activation of partial seizures with motor signs during cyclic alternating pattern in human sleep.

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    Both interictal and ictal EEG phenomena are commonly activated by functional instability. The different non-REM sleep stages comprise long-lasting periods of cyclic alternating pattern (CAP) in which arousal fluctuates between 'A phases' of greater arousal and 'B phases' of less arousal, and periods in which vigilance maintains a tonic stability (non-CAP). Previous studies have revealed that phase A induces a marked enhancement of generalized EEG paroxysms, a minor though significant activation of focal lesional bursts, but no effect on rolandic functional spikes. Conversely, phase B exerts an inhibitory modulation, especially on bilateral interictal phenomena. Because of the opposite influence of phase A and phase B also on muscle tone, we assessed the amount and distribution of nocturnal partial motor seizures in 6 subjects affected by focal epilepsy. The polysomnograms included 45 motor seizures, 43 of which occurred during non-REM sleep. Nocturnal fits were significantly more frequent in stages 1 and 3 (P less than 0.0001). Among the non-REM seizures, 42 appeared in CAP (P less than 0.0001) and always in phase A. The transient arousal and the concomitant muscle tone activation expressed by phase A of CAP is likely to support the motor components of nocturnal seizures. Sleep analysis in terms of CAP and non-CAP provides a better understanding of the continuum from subclinical EEG paroxysms to clinical manifestations and of the relations between vigilance and seizure disorders

    Effects of micronised dispersible ferric pyrophosphate combined with alpha-lactalbumin in pregnant women affected by iron deficiency anemia: Results from a prospective, double-blind, randomized controlled trial

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    OBJECTIVE: This study aimed at evaluating the effects obtained by administering 30 mg of micronised dispersible ferric pyrophosphate plus 300 mg of alpha-lactalbumin (MDFP-AL) compared to 80 mg of ferrous gluconate (FG) in pregnant women affected by iron-deficiency anemia (IDA). PATIENTS AND METHODS: We considered eligible all second-trimester singleton pregnancies in women affected by IDA. We excluded any other disease, twin pregnancies, any other pharmacologic/nutraceutical treatments (besides folic acid) before/during pregnancy. We randomized patients in two groups: one underwent treatment with 1 tablet of MDFP-AL/day, the other one with 1 tablet of FG/day, for 30 days. We evaluated hemoglobin (Hb), ferritin, red blood cells (RBCs), serum iron, hematocrit (Hct), and side effects at baseline (T0), after 15 days (T1) and 30 days (T2). RESULTS: 50 women met the inclusion/exclusion criteria. We did not observe significant differences between the two groups for mean age, gestational age at the enrollment and parity. In MDFP-AL group, after 15 days (T1) Hb, ferritin, serum iron and Hct and were significantly improved respect to baseline (T0); after 30 days (T2), all the parameters, including RBCs, were significantly improved respect to baseline (T0). Similarly, in FG group the investigated parameters were improved both after 15 (T1) and 30 days (T2) respect to baseline (T0), although less in percentage terms respect to MDFP-AL group. The side effects rate was 24% in FG group, whereas MDFP-AL group did not show any significant side effect. CONCLUSIONS: Overall, MDFP-AL is more effective and safe than FG for the treatment of IDA in pregnant women
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