Incompatibility Reaction Research Articles

Cross-incompatibility between two sympatric polyploid Solanum species

Preliminary results from a large number of reciprocal crosses between the closely related sympatric species S. gourlayi Hawkes (2n=4x=48) and S. oplocense Hawkes (2n=6x=72) indicated that they are difficult to hybridize. Pollen-pistil incompatibility barriers were detected via fluorescent microscopy. The cross incompatibility reaction occurred at three sites in 6x×4x crosses; on the stigma, in the first one-third of the style, and in the first two-thirds of the style. In the reciprocal 4x×6x crosses the incompatibility reaction invariably occurred in the ovary. Backcrosses of interspecific pentaploid hybrids (that were occasionally formed) to both parental populations were fully compatible, partially compatible, and fully incompatible with three sites of cross-incompatibility reaction similar to those observed in 6x×4x crosses, respectively. Both polyploid species were found to be selfcompatible, whereas their F1 hybrids were found to be self-incompatible. An hypothesis based on interactions of dominant cross-incompatibility (CI) genes in pistils and dominant specific complementary genes in pollen grains is postulated to explain these observations. The cross-incompatibility system that appears to be operating in nature between 4x S. gourlayi and 6x S. oplocense provides a way for gene exchange between sympatric populations without threatening the identity of either species.

Histological comparison of compatible, mesothetic and incompatible reactions between Puccinia graminis tritici and wheat

Three races of Puccinia graminis tritici developed by successive mutations to give increased virulence (i.e., incompatible → mesothetic → compatible) on the Sr6 gene for resistance were compared histologically on cv. McMurachy (Sr6 gene) growing at 20.5 °C. The length of the longest hyphae and the size of the lesions remained similar in the three interactions up to 3 days after inoculation and then comparative degrees of growth occurred in the following decreasing order; compatible > mesothetic > incompatible. Necrotic cells in the compatible interaction were infrequent (maximum of 6% of infection sites) and hyphae radiated out from the point of ingress in an unimpeded manner. Although necrosis in the incompatible interaction occurred 1 day in advance of necrosis in the mesothetic reaction, by the 6th day, 98–100% of the infection sites in both systems had necrotic cells. In the mesothetic reaction, hyphae grew beyond the area of necrosis in a high proportion (70% at day 6) of the infection sites whereas the incidence of such growth was much less (8% at day 6) in the incompatible reaction. The role of the hypersensitive reaction in these interactions is discussed.

Floral Rewards: Alternatives to Pollen and Nectar

In angiosperms selection has led to the utilization of numerous substances other than pollen and nectar that help to insure repeated visitation by pollinating animals. Here, we group the various substances into nonnutritive and nutritive rewards and discuss within each group the specific kinds that occur. In our discussion of nutritive rewards, we emphasize floral oils, lipids produced by one of two types of specialized secretory organs called elaiophores and which serve as nutritive rewards for certain New World anthophorine bees. Although discovered only within the last 15 years, the syndrome of oil production now appears to be one of the most widespread kinds of floral rewards. We report here for the first time the occurrence of oil production in the Solanaceae (Nierembergia). It is apparent that oil production has evolved independently many times, but plants which produce oils that are collected by female anthophorine bees show similarities in the chemistry of the oils and the types of structures that produce them. It is not clear whether other groups of plants reported to produce oils but which are not pollinated by anthophorine bees possess an analogous system or not. Floral rewards can be considered any component of a flower or inflorescence that is used by animals and, because of this use, insures repeated visitation that will lead to pollination. Without doubt, pollen and nectar are the primary rewards offered by flowers to visiting animals in order to buy their services as pollinating agents. Of the two, nectar is sought by a wider array of animals than pollen. On the other hand, pollen is the primary reward for which bees, probably the single most important group of pollinators, visit flowers. The role of pollen and nectar in the attraction of potential pollinators has been appreciated for hundreds of years, but we have only recently begun to realize the complex nature of these two rewards. Nectar, for example, formerly considered to be a simple sugar solution, has been shown to consist of a variety of chemicals dissolved, or suspended, in an aqueous solution. These range from mixtures of one to three common sugars (glucose, sucrose and fructose) to more complex sugar solutions (Percival, 1961) or combinations of sugars, free amino acids, vitamins, lipids, and other compounds (Baker & Baker, 1975; Baker, 1978). The complex chemical nature of pollen has been realized for a century (refs. in Barbier, 1971), but only in the last twenty years have researchers begun to explore the varied nature of specific enzymes contained in the pollen walls and their possible roles in incompatibility reactions (Stanley & Linskens, 1974). These same enzymes may play a role in pollen recognition by specific pollinators. The chemistry of pollen is in fact so complex that it has been impossible to provide a precise description of pollen chemistry that is all-inclusive. The continued elucidations of the intricate nature of these common rewards has spurred studies of pollination biology and provided an impetus for the investigation or reinvestigation of other floral rewards.

Penetration and growth of compatible and incompatible races of Phytophthora megasperma var. sojae in soybean hypocotyl tissues differing in age

Intact 6-day old soybean hypocotyls (Glycine max L., cv. Altona) were inoculated with zoospores of Phytophthora megasperma Drechs. var. sojae Hildeb. either at the top (susceptible to compatible races, resistant to incompatible races) or the bottom (resistant to both compatible and incompatible races) and, after a 22-h incubation, were examined by light microscopy. Penetration at the top and bottom by both compatible (race 6) and incompatible (race 4) P. megasperma var. sojae was predominantly between anticlinal walls of epidermal cells. Both races, but especially race 4, also penetrated directly into the outer walls of epidermal cells, but epidermal cells rarely were invaded. Both races grew mainly intercellularly, but race 6 produced haustoria more frequently than race 4. Race 6 haustoria at the top of the hypocotyl were usually encased, those of race 4 were not. Growth of both races was equally dense in the first few cell layers, but the numbers of race 4 hyphae decreased rapidly while those of race 6 became more abundant in the deeper layers. With race 4, but not with race 6, most cells in the infected tissue were necrotic. Differences between the compatible and the incompatible interactions were not absolute; there were many unsuccessful invasion attempts by race 6 and individual hyphae of race 4 spread deeply into the tissue. At the bottom of the hypocotyl, growth of both races was more restricted. Race 6 produced fewer haustoria than at the top, and similarities to the incompatible reaction with race 4 at the top suggest that similar mechanisms of resistance may be involved.

Plasmids coding for heat-labile enterotoxin production isolated from Escherichia coli O78: comparison of properties.

Nineteen enterotoxigenic Escherichia coli strains of serogroup O78, isolated in different geographical areas from humans with diarrheal diseases, were tested for their ability to transfer enterotoxin production. All of the strains originally produced heat-labile enterotoxin, and 16 also produced heat-stable enterotoxin and colonization factor antigen I. Plasmids coding for the production of heat-labile enterotoxin only were transferred from 13 strains. Some properties of these plasmids were compared. All were fi+, but they could be divided into three groups on the basis of their incompatibility reactions, ability to restrict E. coli K-12 phages, and size. The three heat-labile enterotoxin plasmids isolated from African strains all belonged to one enterotoxin plasmid group. The heat-labile enterotoxin plasmids from the Asian strains were divided into two groups, those from serotype O78.H11 differing from those from serotype O78.H12.

Ultrastructural and histochemical features of pistil of Malus communis: The stylar transmitting tissue

The structural and histochemical features of the stylar transmitting tissue of Malus communis were investigated by light and transmission electron microscopy. The transmitting tissue of apple is composed of cells and intercellular substance. The cells are very rich in cytoplasm and are characterized by numerous large rough endoplasmic reticulum (RER) cisterns, and by large Golgi vesicles rich in polysaccharides. The intercellular substance, probably secreted by transmitting tissue cells, contains proteins and polysaccharides. A possible role of the intercellular substance in the incompatibility reaction is discussed.

Genetic analysis of incompatibility in the diploid Ipomoea species closely related to the sweet potato

In order to identify the genotypic constitutions of incompatibility in the diploid species, Ipomoea leucantha Jacq. (K221), which is most closely related to the sweet potato, the progenies derived from the reciprocal crosses, backcrosses and testcrosses were analysed. All the plants examined were self-incompatible, and pollen germination was inhibited on the stigma after incompatible pollinations. No reciprocal differences were found in the incompatibility reactions. In the progenies three incompatibility groups were observed which showed the rather simple segregation ratios. The homozygous plants for incompatibility alleles were obtained in the progenies. The experimental results demonstrated a sporophytic type of incompatibility controlled by a single locus with multiple S-alleles exhibiting a dominance relationship in both the pollen and the stigma. The plants obtained in the progenies had the following genotypes: S 1 S 2, S 1 S 3, S 2 S 2, S 2 S 3 and S 3 S 3.

The serological investigation of red cell incompatible transfusion reactions.

The hospital blood bank plays a key role in the diagnosis of acute transfusion reactions involving red cell incompatibility. This paper discusses the interpretation of the serological tests performed by the laboratory. Because red cell incompatible transfusion reactions occur so infrequently it is difficult to accumulate practical experience in their laboratory presentation and this paper describes several of the pitfalls that may be encountered when laboratory findings deviate from classical descriptions. These include the absence of a positive direct antiglobulin test (Coombs) or an incompatible crossmatch, the absence of any apparent discrepancy between the pre- and post-transfusion specimens in cases of ABO incompatibility, the differentiation of auto-immune haemolytic anaemia from delayed transfusion reactions and the assessment of the clinical significance of any blood group antibodies that may be detected.

Significance of Incompatibility Reactions of Rhizobium japonicum Strains with Soybean Host Genotypes1

A sample of soybean [Glycine max (L.) Merr.] plant introductions from Asia, representing maturity groups 00 through X, was tested for the presence of the Rj2 and Rj4 genes. Both of these genes condition ineffective nodulation responses: Rj2, specifically with the cl and 122 serogroups of Rhizobium japonicum; Rj4, with R. japonicum strain 61. Rj2 was present in 19 of the 851 fines tested. The 19 lines were in maturity groups III to VIII and most originated from China and Japan. Rj4 was present in 261 of the 851 lines tested, and was most prevalent in lines from southeast Asia. This gene occurred in lines from maturity groups 00 to X and was most frequent in Group X with 94% of the lines possessing it. This evidence of geographical differences in gene frequencies suggests that the combinations of host and Rhizobium ecotypes which coevolved in Asia may have been disrupted through separate introduction of the host and microsymbiont to the New World. If this is the case, N2 fixation may be improved by reassembling the host/strain combinations that evolved in Asia. Use of incompatibility responses may enable soybean breeders to control host specification of symbiosis with genetically improved Rhizobium strains. Host compatibility with indigeneous Rhizobium strains may profoundly affect performance of some plant introductions in evaluation nurseries on soils of low N fertility. Management of N fertility in such nurseries will depend on breeders' objectives.

Genetic versatility of incompatibilty in plants

Abstract Flowering plants have at least 11 different self-incompatibility systems; most, if not all, are oppositional systems in which an incompatible reaction occurs between like alleles in pollen and style. Higher fungi have complementary systems in which compatibility is due to the presence of unlike alleles in the mating cells. This is shown to be a natural consequence of the contrast between haploid pollen entering a diploid style in a plant, and a dikaryotic cell presenting one nucleus to enter a haploid monokaryotic cell of a fungus. From the genetic dominance, co-dominance, and negative complementation (competition), the polymeric state of the S gene product is deduced as: a polymer in pollen and a monomer in the style of gametophytic systems, with the exception of a pollen co-polymer in grasses and a pollen monomer or co-polymer in Tradescantia paludosa; in the multiallelic sporophytic system a polymer is presumed in both pollen and style. Four-gene systems are discussed and evidence is given for...

Sexual and vegetative incompatibility reactions in Phellinus weirii

Phellinus weirii is a heterothallic basidiomycete lacking clamp connections. Compatible pairings of single-spore isolates have a changed colony morphology, faster growth, and fewer nuclei per cell than the single-spore isolates alone. Compatible pairings occasionally form basidiocarps in culture. Single-spore isolates from different fruiting bodies are sexually compatible; most single-spore isolates from the same fruiting body are incompatible. Vegetative incompatibility is manifested by a line of demarcation formed when two dissimilar heterokaryotic isolates meet. Line formation is a sensitive indicator of genetic differences between heterokaryons or between heterokaryons and homokaryons.

The possible association of phytoalexins with resistance gene expression in flax to Melampsora lini

Two antifungal compounds, coniferyl alcohol and coniferyl aldehyde, were isolated from facilitated dilusates of flax leaves inoculated with incompatible races of Melampsora lini. The two phenylpropanoid compounds accumulated more rapidly in all incompatible reactions than in compatible. In addition, the compounds accumulated more rapidly in resistance genotypes typified by rapid restriction of fungus growth and smaller lesions than in resistance genotypes typified by later restriction of fungus growth and larger lesion areas. Phloroglucinol stained incompatible infection sites, but not those of compatible sites, thus indicating that coniferyl aldehyde accumulation and perhaps induced lignification occurred in the incompatible sites. Initial detection of phloroglucinol-staining was chronologically correlated with the cessation of fungus growth and inversely correlated with ultimate lesion size. The evidence indicated that de novo production of coniferyl alcohol and coniferyl aldehyde may be the mechanism for restriction of fungus growth in incompatible flax leaves and that the phenylpropanoid compounds may represent phytoalexins effective against M. lini.

Genetics of incompatibility inCorylus avellana L.

Diallele crosses of sibs and parents of 3 parental combinations demonstrated sporophytic type of incompatibility inCorylus avellana L. One gene with multiple alleles was indicated. All 6 alleles present in the 4 parental cultivars and in their progeny exhibited dominance in pollen and independent action in the pistil. Individuals homozygous for S-alleles appeared in progeny of parents having one allele in common. Reciprocal differences occurred in some crosses. The stigmatic surface is the site of the incompatibility reaction. Incompatible pollen germinated abundantly but failed to penetrate into the stigma cells.

THE EVOLUTION AND BREAKDOWN OF TRISTYLY.

In a tristylic species three types of individuals, distinguished by their flower morphology, occur. One form has a long style, while the anthers are in two whorls, one very low down, and one about half way between the stigma and the low anther whorl. The three positions of the sex organs in this form (called long or L) define three positions that can be occupied by anthers or stigmas in the two other forms. In short (S) individuals, the style is very short, and the anthers occupy mid (m) and long (1) positions; in mid (M) plants, the stigma occupies the middle position and the anthers the 1 and s positions. Darwin (1877) showed in several tristylic species that pollen from the different anther positions differed in its incompatibility reactions in such a way that a form with stigmas at a given level can be successfully fertilized only by pollen from anthers at the same level; this pollen will necessarily come from another individual, but it may come from either of the two forms other than that of the stigma-bearing plant in question. Tristyly is known in three families only (Lythraceae, Oxalidaceae and Pontederiaceae). Genera with tristylic species often also contain dimorphic and sometimes monomorphic populations (e.g., Darwin, 1877; Ornduff, 1964; Mulcahy, 1964; Lewis and Rao, 1971; Weller and Denton, 1976; and Barrett, 1979). It seems unlikely that these represent stages in the evolution of tristyly, because in many such cases there are features that appear to be residual tristylic characters (e. g., Lewis and Rao, 1971; Weller, 1976; and Barrett, 1979). In Lythrum, nearly all Old World species are trimorphic with two whorls of stamens, or monomorphic annuals with one stamen set, while all New World species are dimorphic (probably L and M, according to a personal communication from Ornduff) and have one stamen set. Here again, it seems most likely that trimorphism is the ancestral condition, since the presence of two anther whorls is characteristic of all three families with tristyled members (Lewis and Rao, 1971). In the present paper, the non-tristylic species in tristyled genera are therefore regarded as secondarily derived from tristyly. Probably the commonest type of breakdown of tristyly is loss of the mid form, giving a dimorphic (L and S) population, but various other forms of breakdown are known in Oxalis (reviewed by Ornduff, 1972); and in the Pontederiaceae (Barrett, 1979), and the dimorphic Lythrums may represent another exception. The genetics of tristyly has been worked out in several species. The genetic control is basically the same in Lythrum salicaria (Fisher and Mather, 1943), in section Ionoxalis of the genus Oxalis (Weller, 1976a) and in Eichhornia crassipes (Barrett, 1978a), although Lythrum and Eichhornia are polyploids, while most of the Oxalis species are not. 0. rosea may, however, have a different system (Von Ubisch, 1926; Fyfe, 1956). In section Ionoxalis, two genes control tristyly. The L form has the genotype ssmm. The dominant allele M determines mid-level stigmas in ss plants, and S (which is dominant to s and epistatic to M) determines the short stigma position. Thus S plants could have any one of six possible genotypes, though several of these will not be found in natural tristylic populations. While it is clear that this genetic system gives a tristylic equilibrium population (Fisher, 1941; Finney, 1952), it is by no means obvious how it could evolve. It

Post-fusion somatic incompatibility in plasmodia of Physarum Polycephalum

High-resolution autoradiography has been used to establish that during the incompatibility reaction that follows fusion between plasmodia of a 'killer' and a 'sensitive' strain of the myxomycete Physarum polycephalum, the nuclei of the sensitive strain are selectively damaged, enclosed in vacuoles and eliminated from the cytoplasm. This damage is visible as increased chromatin condensation and nucleolar segregation. Nuclear envelopes of both strains show blebbing, and there is an increase in the size and frequency of cytoplasmic vesicles of endoplasmic reticulum. Multiple nuclear fusions are seen between all combinations of genetically like and unlike types of nuclei throughout the course of the incompatibility reaction. After the reaction, mean nuclear diameters increase over 2-3 days to give nuclei an order of magnitude greater in volume than the controls; the population size range returns to normal in 4-5 days. Fusions between incompatible plasmodia carried out when the killer strain is at or very near to mitosis do not produce an immediate incompatibility reaction, but give plasmodia that are neutral and act as neither killers nor sensitives; these heterokaryons convert to killer phenotypes after a few days.

Clinico-experimental study on prevention of the complications following incompatible blood transfusion

The accident of incompatible blood transfusion is not infrequent in practical medicine. The acute hemolytic transfusion reaction sometimes results severe complications. In authors' experience in the treatment and clinical analysis of this disorder during last one decade, there were some evidences that disseminated intravascular coagulation attributed in considerable extent to the development of such complications as shock, hemorrhagic tendencies and acute renal failure. In this paper, six patients received incompatible blood transfusion are reviewed and some therapeutic approaches are presented.On the hypothesis that DIC is a primary pathogenetic mechanism involved in these hemolytic reaction, authors have learned that the heparin therapy would be the best at interfering with these pathophysiologic pathways, and have been getting the benifits in prevention of severe complications or of exaggeration of signs and symptoms developed. Of 6 cases presented, five of the incompatibilities were in ABO system and one in Rh system. A 26-year-old female, blood group 0, Rh positive, was given a transfusion with 0 positive blood but she was positive in anti-E antibody. The amount of blood transfused were 50-350ml in ABO incompatibilities and 1, 000ml of E-positive blood in a Rh-incompatible case.Hemostatic studies were done in 3 patients. One patient received ABO incompatible blood revealed clotting abnormalities even 2 days after the heparin administration. The case with positive E-antibody developed acute renal failure. Severe bleeding tendency was observed at the Cesarian section when she was given more than 1, 500ml of blood. Thrombocytopenia, positive tests in FDP and protamine sulfate test and prolongation of thrombin time and serial thrombin time were seen in these 2 cases. Remaining one patient who was given heparin just after the accident showed no coagulation disturbance when tested during heparin therapy. Five patients received mismatched blood in ABO system were all given heparin as soon as possible after the accident to prevent severe reactions due to DIC. All were symptomatically uneventful, however, the elevation of FDP and thrombocytopenia were noted in one as mentioned above and moderate increase of blood urea nitrogen in three clinical courses. These findings seem to represent the subclinical participation of clotting episodes in mismatched transfusion reactions even after the heparin administration. Therefore, the occurrence of DIC may be more frequent that has been appreciated and prompt treatment with heparin prior to the recognition of signs and symptoms may decrease the morbidity and mortality from incompatible transfusion reactions.

TRANSFERABLE DRUG RESISTANCE IN MAN AND ANIMALS: GENETIC RELATIONSHIP BETWEEN R‐PLASMIDS IN ENTERIC BACTERIA FROM MAN AND DOMESTIC PETS

SUMMARY Enteric bacteria isolated from morbid human and domestic pet populations in Canberra were examined for multiple antibiotic resistance, the transferability of such resistance, and the genetic incompatibility reactions of the presumptive R‐plasmid concerned.More than one‐third of the isolates obtained from domestic pets were resistant to one or more of the antibiotics tested (ampicillin, chloramphenicol, kanamycin, nalidixic acid, streptomycin, sulfathiazole, tetracycline). Ampicillin resistance was invariably a part of all multiple resistance patterns seen. Half of the resistant bacteria from pets were resistant to 5 or more of the antibiotics, with ApCmSmSuTc the most frequent combination of resistance markers. The occurrence of resistance to Km and Nd was low, probably reflecting the infrequent usage of these antibiotics in veterinary practice.Genetic similarities between identifiable R‐plasmids and individual resistance markers in the 2 populations were tested by grouping on the basis of incompatibility reactions against reference plasmids for incompatibility groups Fll, ***lα, N, P and W. The results, though limited in extent by experimental conditions, suggest a close similarity between R‐plasmids in domestic pets and man: the majority of assignable plasmids in each population belong to group Fll***, with smaller numbers falling into groups lα and P.Analysis of individual resistance markers reveals that apart from incompatibility group N (which contained a smaller number of markers), the distribution of resistance markers across the other incompatibility groups was similar for isolates from man and animals. These results are consistent with a common origin of R‐plasmids in man and domestic pets in Canberra, or one population serving as an infection source for the other, or selection influences operating at the level of host bacteria for the plasmids which result in similarities in the bacterial population and thus of plasmid types.

Incompatible reactions between some plants and pathogenic bacteria

Incompatible combinations of plant and plant bacteria produce an incompatible reaction at different rates, producing, besides the typical hypersensitive reaction, also darkening, yellowing, and fading. Plants differ in their responsiveness to plant bacteria in terms of reaction rate. Study of incompatible reactions may differentiate the species and strains of plant bacteria if properly explored.

Effect of hexane and humidity on self-incompatibility in Brassica oleracea

The effects of hexane, high humidity, flower age and temperature in overcoming the self-incompatibility of Brassica oleracea were studied using three plants, each of which was homozygous for a different dominant S-allele. Hexane had a significant effect in all cases, but the size of the effect varied considerably. In one plant there was a marked interaction between the effect of hexane, humidity and flower age, but temperature had relatively little effect. In another plant high humidity alone gave a very much greater response than hexane alone. This plant gave as many self-seeds from the high humidity treatment as from bud selfing, indicating that the incompatibility reaction was almost completely overcome by the high humidity. The results are discussed in the light of current views of the mechanism of incompatibility in Brassica.

Incompatibility studies in the genus Gibasis section Heterobasis D. R. Hunt (Commelinaceae)

Two species in the genus Gibasis section Heterobasis have been examined to confirm their incompatibility reaction and to determine its genetic control. Five individuals of G. oaxacana (2x=16) from a single Mexican population (Hunt 8175) were found to be self-incompatible. Three accessions of tetraploid cytotypes (4x=32; Hunt 7012, 7072 and 7160) and two accessions of hexaploid cytotypes (6x=48; Jones 72 and Bacigallipo 711257) of Gibasis geniculata were found to be self-compatible. Analysis of an F1 population raised from an intercross between two heterozygous genotypes of G. oaxacana was consistent with an hypothesis that self-incompatibility is controlled by a single multiallelic gene acting gametophytically in the pollen. Unilateral incompatibility was found in crosses between G. oaxacana and G. geniculata.