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Physiologia Plantarum 2024During microspore embryogenesis, microspores are induced to develop into haploid embryos. In Brassica napus, microspore embryogenesis is induced by a heat shock (HS),...
The different response of Brassica napus genotypes to microspore embryogenesis induced by heat shock and trichostatin A is not determined by changes in cell wall structure and composition but by different stress tolerance.
During microspore embryogenesis, microspores are induced to develop into haploid embryos. In Brassica napus, microspore embryogenesis is induced by a heat shock (HS), which initially produces embryogenic structures with different cell wall architectures and compositions, and with different potentials to develop into embryos. The B. napus DH4079 and DH12075 genotypes have high and very low embryo yields, respectively. In DH12075, embryo yield is greatly increased by combining HS and the histone deacetylase (HDAC) inhibitor trichostatin A (TSA). However, we show that HS + TSA inhibits embryogenesis in the highly embryogenic DH4079 line. To ascertain why TSA has such different effects in these lines, we treated DH4079 and DH12075 microspore cultures with TSA and compared the cell wall structure and composition of the different embryogenic structures in both lines, specifically the in situ levels and distribution of callose, cellulose, arabinogalactan proteins and high and low methyl-esterified pectin. For both lines, HS + TSA led to the formation of cell walls unfavorable for embryogenesis progression, with reduced levels of arabinogalactan proteins, reduced cell adhesion of inner walls and altered pectin composition. Thus, TSA effects on cell walls cannot explain their different embryogenic response to TSA. We also applied TSA to DH4079 cultures at different times and concentrations before HS application, with no negative effects on embryogenic induction. These results indicate that DH4079 microspores are hypersensitive to combined TSA and HS treatments, and open up new hypotheses about the causes of such hypersensitivity.
Topics: Brassica napus; Cell Wall; Hydroxamic Acids; Heat-Shock Response; Genotype; Pollen; Stress, Physiological
PubMed: 38923567
DOI: 10.1111/ppl.14405 -
Allergy Jun 2024
PubMed: 38923532
DOI: 10.1111/all.16211 -
Plant Physiology Jun 2024The intricate process of male gametophyte development in flowering plants is regulated by jasmonic acid (JA) signaling. JA signaling initiates with the activation of the...
The intricate process of male gametophyte development in flowering plants is regulated by jasmonic acid (JA) signaling. JA signaling initiates with the activation of the basic-helix-loop-helix (bHLH) transcription factor (TF), MYC2, leading to the expression of numerous JA-responsive genes during stamen development and pollen maturation. However, the regulation of JA signaling during different stages of male gametophyte development remains less understood. This study focuses on the characterization of the plant ARID-HMG DNA-BINDING PROTEIN 15 (AtHMGB15), and its role in pollen development in Arabidopsis (Arabidopsis thaliana). Phenotypic characterization of a T-DNA insertion line (athmgb15-4) revealed delayed bolting, shorter siliques, and reduced seed set in mutant plants compared to the wildtype. Additionally, AtHMGB15 deletion resulted in defective pollen morphology, delayed pollen germination, aberrant pollen tube growth, and a higher percentage of non-viable pollen grains. Molecular analysis indicated the down-regulation of JA biosynthesis and signaling genes in the athmgb15-4 mutant. Quantitative analysis demonstrated that jasmonic acid and its derivatives were approximately tenfold lower in athmgb15-4 flowers. Exogenous application of methyl jasmonate could restore pollen morphology and germination, suggesting that the low JA content in athmgb15-4 impaired JA signaling during pollen development. Furthermore, our study revealed that AtHMGB15 physically interacts with MYC2 to form a transcription activation complex. This complex promotes the transcription of key JA signaling genes, the R2R3-MYB TFs MYB21 and MYB24, during stamen and pollen development. Collectively, our findings highlight the role of AtHMGB15 as a positive regulator of the JA pathway, controlling the spatiotemporal expression of key regulators involved in Arabidopsis stamen and pollen development.
PubMed: 38922580
DOI: 10.1093/plphys/kiae355 -
Planta Jun 2024The characterisation of PLA genes in the sorghum genome using in-silico methods revealed their essential roles in cellular processes, providing a foundation for further...
The characterisation of PLA genes in the sorghum genome using in-silico methods revealed their essential roles in cellular processes, providing a foundation for further detailed studies. Sorghum bicolor (L.) Moench is the fifth most cultivated crop worldwide, and it is used in many ways, but it has always gained less popularity due to the yield, pest, and environmental constraints. Improving genetic background and developing better varieties is crucial for better sorghum production in semi-arid tropical regions. This study focuses on the phospholipase A (PLA) family within sorghum, comprehensively characterising PLA genes and their expression across different tissues. The investigation identified 32 PLA genes in the sorghum genome, offering insights into their chromosomal localization, molecular weight, isoelectric point, and subcellular distribution through bioinformatics tools. PLA-like family genes are classified into three groups, namely patatin-related phospholipase A (pPLA), phospholipase A1 (PLA), and phospholipase A2 (PLA). In-silico chromosome localization studies revealed that these genes are unevenly distributed in the sorghum genome. Cis-motif analysis revealed the presence of several developmental, tissue and hormone-specific elements in the promoter regions of the PLA genes. Expression studies in different tissues such as leaf, root, seedling, mature seed, immature seed, anther, and pollen showed differential expression patterns. Taken together, genome-wide analysis studies of PLA genes provide a better understanding and critical role of this gene family considering the metabolic processes involved in plant growth, defence and stress response.
Topics: Sorghum; Gene Expression Regulation, Plant; Genome, Plant; Phospholipases A; Plant Proteins; Phylogeny; Chromosomes, Plant; Promoter Regions, Genetic
PubMed: 38922509
DOI: 10.1007/s00425-024-04467-2 -
Brazilian Journal of Biology = Revista... 2024The identification of meliponicultural flora is fundamental for the preservation of bees, as well as enabling the development of pollinator management and reforestation...
Pollen analysis of honey and pollen stored by Melipona (Melikerria) fasciculata Smith, 1854 (Apidae Meliponini), in an Amazon and Cerrado transition area, Maranhão, Brazil.
The identification of meliponicultural flora is fundamental for the preservation of bees, as well as enabling the development of pollinator management and reforestation programs. In this context, this study aimed to investigate the types of pollen found in the honey and pollen pots of the Melipona fasciculata bee in Arari, State of Maranhão, between August 2022 and July 2023. 40 types of pollen were identified, distributed among 18 botanical families, with Fabaceae standing out (46.15% in pollen pots and 37.86% in honey pots), Myrtaceae (11.53% in pollen and 13.51% in honey) and Rubiaceae (7.69% in pollen and 5.40% in honey). Sapindaceae, in the honey pots, accounted for 5.40%. The other families showed lower percentages, 3.84% in the pollen pots and 2.70% in the honey pots. In terms of similarity, two distinct groups were observed in both the pollen and honey pots. In the pollen pots, group A (May-June ~ 97%) and group B (Feb-Mar ~ 99%) stood out, while in the honey pots, group A (Mar-Apr ~ 98%) and group B (Jun-Jul-Sept ~ 98%) showed the highest percentages. These findings highlight the wide range of resources used by the M. fasciculata species, as well asits preference for Fabaceae and Myrtaceae, due to the diversity and availability of trophic resources. An understanding of the meliponicultural flora is essential to support effective conservation strategies, which aim not only to guarantee the survival of the bees, but also to ensure the continued production of honey, a resource of great importance to local communities.
Topics: Pollen; Honey; Bees; Animals; Brazil; Seasons; Pollination
PubMed: 38922195
DOI: 10.1590/1519-6984.281066 -
Insects Jun 2024are predaceous mites that feed on phytophagous mites, pollens, and plant exudates and are known as one of the most potent biological pest management agents. is a...
are predaceous mites that feed on phytophagous mites, pollens, and plant exudates and are known as one of the most potent biological pest management agents. is a global mite that is difficult to manage because of its high population growth rates, necessitating alternative management measures like biological control. Regarding the functional response, the effects of temperature and prey density are some of the essential behaviors of natural enemies. This study investigates the effect of varying temperatures and prey densities on , a biological control agent for . The present results demonstrated the change in the functional response estimates when was reared at various temperatures and different prey densities. The results of the estimates regarding the searching efficiency () showed the highest value ( = 0.919) at 26 °C and the lowest value ( = 0.751) at 14 °C. The handling time per prey item () for the predatory mites changed with the temperature and prey density, showing the shortest handling time at 26 °C ( = 0.005) and the highest value at 14 °C ( = 0.015). The functional response curves matched the type II functional response model, demonstrating the inverse dependence of temperatures and prey density with a positive quadratic coefficient. The predation curves for showed a significant difference between the mean numbers of consumed at various prey densities and temperatures, illustrating a relationship between and Therefore, the results of this research may be utilized to forecast the behavior of and its usefulness in controlling populations.
PubMed: 38921159
DOI: 10.3390/insects15060444 -
Insects Jun 2024Hybrid rice results from crossing a male-sterile line (the A line) with a pollen doner (the restorer or R line). In 3-line hybrid breeding systems, a fertile B line is...
Hybrid rice results from crossing a male-sterile line (the A line) with a pollen doner (the restorer or R line). In 3-line hybrid breeding systems, a fertile B line is also required to maintain A line populations. Heterosis is defined as a condition of traits whereby the hybrid exceeds the average of the parental lines. Heterobeltiosis is where the hybrid exceeds both parents. Hybrid rice may display heterosis/heterobeltiosis for growth, yield and resistance to herbivores, among other traits. In a greenhouse experiment, we assessed the frequency of heterosis for resistance to the brown planthopper ( (BPH)), whitebacked planthopper ( (WBPH)) and yellow stemborer ( (YSB)) in eight hybrids under varying soil nitrogen conditions. We also assessed plant biomass losses due to herbivore feeding as an approximation of tolerance (the plant's capacity to compensate for damage). Nitrogen reduced resistance to all three herbivores but was also associated with tolerance to WBPH and YSB based on improved plant survival, growth and/or yields. Plant biomass losses per unit weight of WBPH also declined under high nitrogen conditions for a number of hybrids, and there were several cases of overcompensation in rice for attacks by this herbivore. There was one case of nitrogen-related tolerance to BPH (increased grain yield) for a hybrid line with relatively high resistance, likely due to quantitative traits. Heterosis and heterobeltiosis were not essential to produce relatively high herbivore resistance or tolerance across hybrids.
PubMed: 38921131
DOI: 10.3390/insects15060416 -
Advances in Respiratory Medicine May 2024Ragweed pollen allergy is the most common seasonal allergy in western Romania. Prolonged exposure to ragweed pollen may induce sensitization to pan-allergens such as...
Ragweed pollen allergy is the most common seasonal allergy in western Romania. Prolonged exposure to ragweed pollen may induce sensitization to pan-allergens such as calcium-binding proteins (polcalcins) and progression to more severe symptoms. We aimed to detect IgE sensitization to recombinant Amb a 9 and Amb a 10 in a Romanian population, to assess their potential clinical relevance and cross-reactivity, as well as to investigate the relation with clinical symptoms. rAmb a 9 and rAmb a 10 produced in were used to detect specific IgE in sera from 87 clinically characterized ragweed-allergic patients in ELISA, for basophil activation experiments and rabbit immunization. Rabbit rAmb a 9- and rAmb a 10-specific sera were used to detect possible cross-reactivity with rArt v 5 and reactivity towards ragweed and mugwort pollen extracts. The results showed an IgE reactivity of 25% to rAmb a 9 and 35% to rAmb a 10. rAmb a 10 induced basophil degranulation in three out of four patients tested. Moreover, polcalcin-negative patients reported significantly more skin symptoms, whereas polcalcin-positive patients tended to report more respiratory symptoms. Furthermore, both rabbit antisera showed low reactivity towards extracts and showed high reactivity to rArt v 5, suggesting strong cross-reactivity. Our study indicated that recombinant ragweed polcalcins might be considered for molecular diagnosis.
Topics: Humans; Immunoglobulin E; Cross Reactions; Rhinitis, Allergic, Seasonal; Romania; Calcium-Binding Proteins; Antigens, Plant; Allergens; Female; Male; Ambrosia; Rabbits; Adult; Plant Extracts
PubMed: 38921061
DOI: 10.3390/arm92030022 -
Antibodies (Basel, Switzerland) Jun 2024The proportion of patients with type I allergy in the world population has been increasing and with it the number of people suffering from allergic symptoms. Recently we...
The proportion of patients with type I allergy in the world population has been increasing and with it the number of people suffering from allergic symptoms. Recently we showed that prophylactic cell therapy employing allergen-expressing bone marrow (BM) cells or splenic B cells induced allergen-specific tolerance in naïve mice. Here we investigated if cell therapy can modulate an established secondary allergen-specific immune response in pre-immunized mice. We sensitized mice against the grass pollen allergen Phl p 5 and an unrelated control allergen, Bet v 1, from birch pollen before the transfer of Phl p 5-expressing BM cells. Mice were conditioned with several combinations of low-dose irradiation, costimulation blockade, rapamycin and T cell-depleting anti-thymocyte globulin (ATG). Levels of allergen-specific IgE and IgG1 in serum after cell transfer were measured via ELISA and alterations in cellular responses were measured via an in vitro proliferation assay and transplantation of Phl p 5 skin grafts. None of the tested treatment protocols impacted Phl p 5-specific antibody levels. Transient low-level chimerism of Phl p 5 leukocytes as well as a markedly prolonged skin graft survival were observed in mice conditioned with high numbers of Phl p 5 BMC or no sensitization events between the day of cell therapy and skin grafting. The data presented herein demonstrate that a pre-existing secondary allergen-specific immune response poses a substantial hurdle opposing tolerization through cell therapy and underscore the importance of prophylactic approaches for the prevention of IgE-mediated allergy.
PubMed: 38920972
DOI: 10.3390/antib13020048 -
Nature Communications Jun 2024The extent of aerial flows of insects circulating around the planet and their impact on ecosystems and biogeography remain enigmatic because of methodological...
The extent of aerial flows of insects circulating around the planet and their impact on ecosystems and biogeography remain enigmatic because of methodological challenges. Here we report a transatlantic crossing by Vanessa cardui butterflies spanning at least 4200 km, from West Africa to South America (French Guiana) and lasting between 5 and 8 days. Even more, we infer a likely natal origin for these individuals in Western Europe, and the journey Europe-Africa-South America could expand to 7000 km or more. This discovery was possible through an integrative approach, including coastal field surveys, wind trajectory modelling, genomics, pollen metabarcoding, ecological niche modelling, and multi-isotope geolocation of natal origins. The overall journey, which was energetically feasible only if assisted by winds, is among the longest documented for individual insects, and potentially the first verified transatlantic crossing. Our findings suggest that we may be underestimating transoceanic dispersal in insects and highlight the importance of aerial highways connecting continents by trade winds.
Topics: Animals; Butterflies; Flight, Animal; Wind; Ecosystem; South America; Europe; Animal Migration; Pollen; Africa; Animal Distribution
PubMed: 38918383
DOI: 10.1038/s41467-024-49079-2