Two Indigenous Berberis Species From Spain Were Confirmed as Alternate Hosts of the Yellow Rust Fungus Puccinia striiformis f. sp. tritici.

Puccinia striiformis f. sp. tritici, which causes yellow (or stripe) rust on wheat, is a macrocyclic and heteroecious fungus. In this study, we investigated whether Berberis vulgaris subsp. seroi and B. vulgaris subsp. australis, which are indigenous in Spain, may serve as alternate hosts for P. striiformis f. sp. tritici. Wheat leaves bearing telia of an isolate of P. striiformis f. sp. tritici were harvested and used to inoculate plants of both barberry subspecies. Pycnia were observed on the adaxial side of the leaves from 10 days after inoculation (dai). Following successful fertilization, aecia were observed on the abaxial side of the leaves from 16 dai. At 27 dai, barberry leaves bearing aecia were detached and used to inoculate susceptible wheat seedlings of cultivar Morocco. Uredinia were observed on wheat seedlings from 12 days after aeciospore exposure. Eighty-three single lesions were recovered from individual wheat leaves, of which 43 were genotyped using 19 P. striiformis f. sp. tritici simple sequence repeat markers (SSR). In total, 19 multilocus genotypes (MLGs) were identified among the 43 progeny isolates. The SSR genotyping confirmed that all 43 isolates were derived from the parental isolate. Seven heterozygous SSR markers showed segregation among the progenies, whereas none of the 12 homozygous markers resulted in segregation. These results demonstrated that B. vulgaris subspp. seroi and australis can serve as alternate hosts for P. striiformis f. sp. tritici, which may result in novel virulence combinations that can have a detrimental impact on wheat production. Although P. striiformis f. sp. tritici has not been detected on these barberry species in nature, this study highlights the importance of rust surveillance in barberry areas where suitable conditions for completion of the sexual life cycle may be present.

The effect of phytoglobin overexpression on the plant proteome during nonhost response of barley (Hordeum vulgare) to wheat powdery mildew (Blumeria graminis f. sp. tritici).

Nonhost resistance, a resistance of plant species against all nonadapted pathogens, is considered the most durable and efficient immune system in plants. To increase our understanding of the response of barley plants to infection by powdery mildew, Blumeria graminis f. sp. tritici, we used quantitative proteomic analysis (LC-MS/MS). We compared the response of two genotypes of barley cultivar Golden Promise, wild type (WT) and plants with overexpression of phytoglobin (previously hemoglobin) class 1 (HO), which has previously been shown to significantly weaken nonhost resistance. A total of 8804 proteins were identified and quantified, out of which the abundance of 1044 proteins changed significantly in at least one of the four comparisons ('i' stands for 'inoculated')- HO/WT and HOi/WTi (giving genotype differences), and WTi/WT and HOi/HO (giving treatment differences). Among these differentially abundant proteins (DAP) were proteins related to structural organization, disease/defense, metabolism, transporters, signal transduction and protein synthesis. We demonstrate that quantitative changes in the proteome can explain physiological changes observed during the infection process such as progression of the mildew infection in HO plants that was correlated with changes in proteins taking part in papillae formation and preinvasion resistance. Overexpression of phytoglobins led to modification in signal transduction prominently by dramatically reducing the number of kinases induced, but also in the turnover of other signaling molecules such as phytohormones, polyamines and Ca2+. Thus, quantitative proteomics broaden our understanding of the role NO and phytoglobins play in barley during nonhost resistance against powdery mildew.

Stem rust in Western Siberia - race composition and effective resistance genes.

Stem rust in recent years has acquired an epiphytotic character, causing significant economic damage for wheat production in some parts of Western Siberia. On the basis of a race composition study of the stem rust populations collected in 2016-2017 in Omsk region and Altai Krai, 13 pathotypes in Omsk population and 10 in Altai population were identified. The race differentiation of stem rust using a tester set of 20 North American Sr genes differentiator lines was carried out. The genes of stem rust pathotypes of the Omsk population are avirulent only to the resistance gene Sr31, Altai isolates are avirulent not only to Sr31, but also to Sr24, and Sr30. A low frequency of virulence (10-25 %) of the Omsk population pathotypes was found for Sr11, Sr24, Sr30, and for Altai population - Sr7b, Sr9b, Sr11, SrTmp, which are ineffective in Omsk region. Field evaluations of resistance to stem rust were made in 2016-2018 in Omsk region in the varieties and spring wheat lines from three different sources. The first set included 58 lines and spring bread wheat varieties with identified Sr genes - the so-called trap nursery (ISRTN - International Stem Rust Trap Nursery). The second set included spring wheat lines from the Arsenal collection, that were previously selected according to a complex of economically valuable traits, with genes for resistance to stem rust, including genes introgressed into the common wheat genome from wild cereal species. The third set included spring bread wheat varieties created in the Omsk State Agrarian University within the framework of a shuttle breeding program, with a synthetic wheat with the Ae. tauschii genome in their pedigrees. It was established that the resistance genes Sr31, Sr40, Sr2 complex are effective against stem rust in the conditions of Western Siberia. The following sources with effective Sr genes were selected: (Benno)/6*LMPG-6 DK42, Seri 82, Cham 10, Bacanora (Sr31), RL 6087 Dyck (Sr40), Amigo (Sr24, 1RS-Am), Siouxland (Sr24, Sr31), Roughrider (Sr6, Sr36), Sisson (Sr6, Sr31, Sr36), and Fleming (Sr6, Sr24, Sr36, 1RS-Am), Pavon 76 (Sr2 complex) from the ISRTN nursery; No. 1 BC1F2 (96 × 113) × 145 × 113 (Sr2, Sr36, Sr44), No. 14а F3 (96 × 113) × 145 (Sr36, Sr44), No. 19 BC2F3 (96 × 113) × 113 (Sr2, Sr36, Sr44), and No. 20 F3 (96 × 113) × 145 (Sr2, Sr36, Sr40, Sr44) from the Arsenal collection; and the Omsk State Agrarian University varieties Element 22 (Sr31, Sr35), Lutescens 27-12, Lutescens 87-12 (Sr23, Sr36), Lutescens 70-13, and Lutescens 87-13 (Sr23, Sr31, Sr36). These sources are recommended for inclusion in the breeding process for developing stem rust resistant varieties in the region.

Worldwide population structure of the wheat rust fungus Puccinia striiformis in the past.

Puccinia striiformis is a basidiomycete causing yellow rust on wheat. The availability of historic samples of this pathogen from the 'Stubbs collection' enabled us to investigate past population structure and temporal dynamics on a global scale. A set of 212 single genotype urediniospore isolates, representing samples collected from five continents between 1958 and 1991, were genotyped using 19 polymorphic microsatellite markers. The population genetic analyses revealed the existence of seven genetic groups in the past worldwide P. striiformis population. This genetic grouping generally corresponded with geographical sample origin except for the Middle East, where six of the seven genetic groups were represented. The presence of many genetic groups in the Middle Eastern population reflected a low differentiation from the populations in East Africa (FST=0.052) and in South Asia (FST=0.064). A high diversity and recombinant population structure was observed in China and South Asia, while a clonal population structure was observed in NW Europe, East Africa and the Mediterranean region. The high genetic diversity in the Himalayan region supported recent studies suggesting a putative center of diversity for P. striiformis in this area. Four of the 89 multilocus genotypes detected were resampled in different geographical regions suggesting long-distance migration in the past. Comparison of the past populations with more recent ones, represented by 309 isolates mainly collected between 2001 and 2009, revealed temporal divergence for all populations except for Northwest Europe. Overall, we observed a clear subdivision within the worldwide population structure of P. striiformis and migration in the past.

Genetic evidence of local adaptation of wheat yellow rust (Puccinia striiformis f. sp. tritici) within France.

Puccinia striiformis f. sp. tritici (PST), a clonal basidiomycete causing yellow rust disease on wheat, has a long record of 'overcoming' cultivar resistance introduced by breeders. Despite the long dispersal capacity of its spores, the French population of PST presents a strong geographical structure, with the presence of a specific pathotype (array of avirulence genes) at high frequencies in the south of France. The genetic diversity underlying this differentiation was analysed by microsatellite and AFLP markers. A total of 213 French isolates belonging to 10 pathotypes collected over a 15-year period were investigated. For each of the 12 microsatellites used, polymorphism resulted from a unique allelic variant associated to the south-specific pathotype. This pathotype was characterized by 40 specific markers over the total of 63 polymorphins detected using 15 AFLP primer combinations. Phylogeographical analysis indicated a strictly clonal structure of the population, and a strong genomic divergence between the northern population and a south-specific clone. Both virulence and molecular data show that the northern French population belongs to the northwestern European population, whereas the southern clone is most likely related to a Mediterranean population, the two subpopulations resulting from the ancient divergence of two clonal lineages. While the virulence complexity in the northern population may be explained by the successive introduction of corresponding resistance genes in cultivars, the maintenance of a simple virulence type in southern France, despite gene flow between the two populations, may be explained in terms of host cultivars repartition and local adaptation to specific host or climatic conditions.

The challenges of expecting, delivering and rearing triplets.

Twenty-one couples with complete sets of triplets aged between four and six years were interviewed about their experiences of being "triplet parents". The diagnosis of triplets had been a shock for most. All triplets were born prematurely, the mean birth weight being 2,000 g. The first time at home was chaotic for most of the parents. They spent more time organizing and arranging their day and less time on emotional care than did parents of single infants. Growing up as a triplet, with constant competition for attention, stimulation and love from the mother (parents), differed a great deal from the situation for singletons and twins. The early relationship between mothers and triplets must be managed differently from that between mothers of singletons and twins. The study shows how important it is for obstetricians, paediatricians and other professionals to understand the specific needs of these families.

Physical and mental development in 4-6-year-old triplets.

A total of 21 families with complete sets of triplets, born within 200 km of Stockholm, were invited to participate in a follow-up study with the aim of assessing the physical and mental development of their triplets at 4-6 years of age. Four families declined to participate in the study and thus the study group consisted of 17 sets of triplets who were born at 33-36 gestational weeks from 1986 to 1989. Mean birth weight was 2104 g (range 1310-2670 g) for the boys and 1882 g (range 1290-2590 g) for the girls. At birth, none of the 51 triplets showed any malformations. No asphyxia or other major complications were noted to have occurred at delivery. The children were examined in their homes with a neurological examination and the Griffiths mental development scales (GMDS). No major physical disabilities were found. In a group of triplets born small for dates, the total GMDS score and most of the subscale scores were significantly lower than for their siblings. In contrast to what has been found in singletons and twins, the differences in mental development between triplet boys and girls were not significant. On the whole, physical and mental development did not differ from what has been found in twins and singletons of the same age and with the same birth weight.

Paramyotonia congenita (Eulenburg): clinical, neurophysiological and muscle biopsy observations in a Swedish family.

A Swedish family with Paramyotonia congenita (Eulenburg) (PMC) is presented. Clinical neurological examination, neurophysiological examination (n = 5) and muscle biopsy (n = 4) were performed. Different clinical features were found in various combinations in the individual family members. The clinical symptoms were: (1) cold-induced myotonia, (2) attacks of weakness, (3) persistent weakness and (4) no symptoms but other signs of muscle affection. In the patients with myotonia, the neurophysiological examination showed spontaneous myotonic discharges which were frequent at room temperature but disappeared after cooling. Furthermore, the amplitude of M. abductor digiti minimi compound action potential, during supramaximal ulnar nerve stimulation, decreased significantly after cooling. In the patients with persistent weakness there were no spontaneous myotonic discharges, but myopathic abnormalities were found in proximal muscle. In the patients with myotonia as well as in the patients with manifest muscle weakness, muscle biopsy showed a variation of muscle fibre diameters, centrally located nuclei, occasional atrophic fibers and an atrophy of type IIB muscle fibres. These findings are unspecific but have been described in PMC patients in earlier studies. An ancestor to the family, who had myotonia, lived in the same town and at the same time as Albert Eulenburg, which may suggest that this family is a part of the originally described family (1).

Thymocytotoxic antibodies in synovial fluid.

Synovial fluid (SF), obtained from patients with juvenile rheumatoid arthritis (JRA), osteochondritis, traumatic synovitis and septic arthritis were tested for the presence of thymocytotoxic activity. Such activity, directed against guinea pig thymocytes, was earlier demonstrated in human serum and shown to be mediated by IgM antibodies and a heat labile factor, most likely complement. The cytotoxic activity was demonstrated in all SFs tested, and was abolished by either one of the following procedures: depletion of IgM by use of anti-IgM-antibody coated protein A-Sepharose, or heating to 56 degrees C for 30 min. Activity was regained when samples inactivated by these two procedures were recombined. The cytotoxic SFs produced similar distortion of cell volume distribution of the target thymocytes as previously has been shown with human serum. The findings indicate that the two cytotoxic activities are identical. In most cases the IgM levels and the cytotoxic activity were lower in SF than in normal serum. Although the material does not permit correlation of cytotoxic activity with specific joint conditions, a high SF cytotoxicity was noted in two out of four patients with JRA. The demonstration of IgM-associated thymocytotoxic activity is of interest both in connection with earlier observations of various specific antibodies in SF and in connection with speculations regarding local immune regulatory activity in the joint.

Type distribution of muscle fibres and their ultrastructure related to intracellular elemental composition as revealed by energy dispersive X-ray microanalysis. A study of multicore myopathy.

Four cases of congenital myopathy, two children and two adults, are described whose light-microscopical and ultrastructural findings are consistent with a multicore myopathy. In all cases a hereditary etiology to the disorders is obvious presumably by an autosomal recessive trait. Fibres with central nuclei and multiple minicores was a prominent finding in all cases. Energy dispersive X-ray microanalysis of single muscle fibres revealed a normal intracellular content of elements (sodium, potassium and chlorine). This is in contrast to the findings in some cases of s.c. myotubular myopathy earlier described from our group where content of sodium and chlorine is markedly increased while that of potassium is decreased. It is suggested that in myotubular myopathy membrane dysfunction causing decreased ionic gradients is an important feature of the pathophysiology while in multicore myopathy other mechanisms, as a suggestion related to mitochondrial and myofibrillar function play a more prominent part. From a diagnostic point of view it seems that X-ray microanalysis can be used to differentiate the two conditions.