High- or Low-Yielding F2 Progeny of Wheat Is Result of Specific TaCKX Gene Coexpression Patterns in Association with Grain Yield in Paternal Parent.

Members of the TaCKX gene family (GFM) encode oxidase/dehydrogenase cytokinin degrading enzymes (CKX), which play an important role in the homeostasis of phytohormones, affecting wheat development and productivity. Therefore, the objective of this investigation was to test how the expression patterns of the yield-related TaCKX genes and TaNAC2-5A (NAC2) measured in 7 days after pollination (DAP) spikes and the seedling roots of parents are inherited to apply this knowledge in the breeding process. The expression patterns of these genes were compared between parents and their F2 progeny in crosses of one mother with different paterns of awnless cultivars and reciprocal crosses of awned and awnless lines. We showed that most of the genes tested in the 7 DAP spikes and seedling roots of the F2 progeny showed paternal expression patterns in crosses of awnless cultivars as well as reciprocal crosses of awned and awnless lines. Consequently, the values of grain yield in the F2 progeny were similar to the pater; however, the values of seedling root mass were similar to the mother or both parents. The correlation analysis of TaCKX GFMs and NAC2 in spikes and spikes per seedling roots reveals that the genes correlate with each other specifically with the pater and the F2 progeny or the mother and the F2 progeny, which shape phenotypic traits. The numbers of spikes and semi-empty spikes are mainly correlated with the specific coexpression of the TaCKX and NAC2 genes expressed in spikes or spikes per roots of the pater and F2 progeny. Variable regression analysis of grain yield and root mass with TaCKX GFMs and NAC2 expressed in the tested tissues of five crosses revealed a significant dependency of these parameters on the mother and F2 and/or the pater and F2 progeny. We showed that the inheritance of yield-related traits depends on the specific cooperative expression of some TaCKX GFMs, in some crosses coupled with NAC2, and is strongly dependent on the genotypes used for the crosses. Indications for parental selection in the breeding of high-yielding lines are discussed.

Are TaNAC Transcription Factors Involved in Promoting Wheat Yield by cis-Regulation of TaCKX Gene Family?

NAC transcription factors (TFs) are one of the largest TF families in plants, and TaNACs have been known to participate in the regulation of the transcription of many yield-regulating genes in bread wheat. The TaCKX gene family members (GFMs) have already been shown to regulate yield-related traits, including grain mass and number, leaf senescence, and root growth. The genes encode cytokinin (CK) degrading enzymes (CKXs) and are specifically expressed in different parts of developing wheat plants. The aim of the study was to identify and characterize TaNACs involved in the cis-regulation of TaCKX GFMs. After analysis of the initial transcription factor data in 1.5 Kb cis-regulatory sequences of a total of 35 homologues of TaCKX GFMs, we selected five of them, namely TaCKX1-3A, TaCKX22.1-3B, TaCKX5-3D, TaCKX9-1B, and TaCKX10, and identified five TaNAC genes: TaNACJ-1, TaNAC13a, TaNAC94, TaNACBr-1, and TaNAC6D, which are potentially involved in the cis-regulation of selected TaCKX genes, respectively. Protein feature analysis revealed that all of the selected TaNACs have a conserved NAC domain and showed a stable tertiary structure model. The expression profile of the selected TaNACs was studied in 5 day-old seedling roots, 5-6 cm inflorescences, 0, 4, 7, and 14 days-after-pollination (DAP) spikes, and the accompanying flag leaves. The expression pattern showed that all of the selected TaNACs were preferentially expressed in seedling roots, 7 and 14 DAP spikes, and flag leaves compared to 5-6 cm inflorescence and 0 and 4 DAP spikes and flag leaves in Kontesa and Ostka spring wheat cultivars (cvs.). In conclusion, the results of this study highlight the potential role of the selected TaNACs in the regulation of grain productivity, leaf senescence, root growth, and response to various stresses.

Transgenerational Paternal Inheritance of TaCKX GFMs Expression Patterns Indicate a Way to Select Wheat Lines with Better Parameters for Yield-Related Traits.

Members of the TaCKX gene family (GFMs) encode the cytokinin oxygenase/dehydrogenase enzyme (CKX), which irreversibly degrades cytokinins in the organs of wheat plants; therefore, these genes perform a key role in the regulation of yield-related traits. The purpose of the investigation was to determine how expression patterns of these genes, together with the transcription factor-encoding gene TaNAC2-5A, and yield-related traits are inherited to apply this knowledge to speed up breeding processes. The traits were tested in 7 days after pollination (DAP) spikes and seedling roots of maternal and paternal parents and their F2 progeny. The expression levels of most of them and the yield were inherited in F2 from the paternal parent. Some pairs or groups of genes cooperated, and some showed opposite functions. Models of up- or down-regulation of TaCKX GFMs and TaNAC2-5A in low-yielding maternal plants crossed with higher-yielding paternal plants and their high-yielding F2 progeny reproduced gene expression and yield of the paternal parent. The correlation coefficients between TaCKX GFMs, TaNAC2-5A, and yield-related traits in high-yielding F2 progeny indicated which of these genes were specifically correlated with individual yield-related traits. The most common was expressed in 7 DAP spikes TaCKX2.1, which positively correlated with grain number, grain yield, spike number, and spike length, and seedling root mass. The expression levels of TaCKX1 or TaNAC2-5A in the seedling roots were negatively correlated with these traits. In contrast, the thousand grain weight (TGW) was negatively regulated by TaCKX2.2.2, TaCKX2.1, and TaCKX10 in 7 DAP spikes but positively correlated with TaCKX10 and TaNAC2-5A in seedling roots. Transmission of TaCKX GFMs and TaNAC2-5A expression patterns and yield-related traits from parents to the F2 generation indicate their paternal imprinting. These newly shown data of nonmendelian epigenetic inheritance shed new light on crossing strategies to obtain a high-yielding F2 generation.

Cis-Regulation by NACs: A Promising Frontier in Wheat Crop Improvement.

Crop traits are controlled by multiple genes; however, the complex spatio-temporal transcriptional behavior of genes cannot be fully understood without comprehending the role of transcription factors (TFs) and the underlying mechanisms of the binding interactions of their cis-regulatory elements. NAC belongs to one of the largest families of plant-specific TFs and has been associated with the regulation of many traits. This review provides insight into the cis-regulation of genes by wheat NACs (TaNACs) for the improvement in yield-related traits, including phytohormonal homeostasis, leaf senescence, seed traits improvement, root modulation, and biotic and abiotic stresses in wheat and other cereals. We also discussed the current potential, knowledge gaps, and prospects of TaNACs.

Genotype-Dependent Effect of Silencing of TaCKX1 and TaCKX2 on Phytohormone Crosstalk and Yield-Related Traits in Wheat.

The influence of silenced TaCKX1 and TaCKX2 on coexpression of other TaCKX gene family members (GFMs), phytohormone regulation and yield-related traits was tested in awned-spike cultivar. We documented a strong feedback mechanism of regulation of TaCKX GFM expression in which silencing of TaCKX1 upregulated expression of TaCKX2 genes and vice versa. Additionally, downregulation of TaCKX2 highly upregulated the expression of TaCKX5 and TaNAC2-5A. In contrast, expression of these genes in silenced TaCKX1 was downregulated. Silenced TaCKX1 T2 lines with expression decreased by 47% had significantly higher thousand grain weight (TGW) and seedling root mass. Silenced TaCKX2 T2 lines with expression of TaCKX2.2.1 and TaCKX2.2.2 decreased by 33% and 30%, respectively, had significantly higher chlorophyll content in flag leaves. TaCKX GFM expression, phytohormone metabolism and phenotype were additionally modified by Agrobacterium-mediated transformation. Two novel phytohormones, phenylacetic acid (PAA) and topolins, lack of gibberellic acid (GA) and changed phytohormone contents in the 7 days after pollination (DAP) spikes of the awned-spike cultivar compared to a previously tested, awnless one, were detected. We documented that major mechanisms of coregulation of the expression of TaCKX GFMs were similar in different spring wheat cultivars, but, depending on content and composition of phytohormones, regulation of yield-related traits was variously impacted.

Vaccine-Derived Immunity in Children With Cancer-Analysis of Anti-Tetanus and Anti-Diphtheria Antibodies Changes after Completion of Antineoplastic Therapy.

BACKGROUND: Cancer survival rates and longevity of patients after therapy have significantly improved during the last decades. Thus durable protection against infections should be provided. The aim of the study was to compare the levels of vaccine-derived antibodies in children with cancer compared to those of healthy children and to investigate how therapy influences the levels of specific antibodies. PROCEDURE: A group of 40 children, diagnosed with acute lymphoblastic leukemia (ALL) or solid tumor (ST), followed in Poznan University of Medical Sciences Department of Pediatric Hematology, Oncology and Bone Marrow Transplantation, were recruited for evaluation of humoral immunity. Antibody levels were checked before treatment and 3, 6, and 12 months after treatment. RESULTS: In patients with ALL or ST, levels of IgG against tetanus and diphtheria were significantly lower than in the control group. Among ALL patients, 9% remained negative for tetanus and diphtheria antibodies 12 months after therapy. Among patients with ST 3 months after chemotherapy, there were no protective antibodies in 12% against tetanus, and in 18% against diphtheria. All patients reconstituted immunity 6 and 12 months after therapy. CONCLUSIONS: Our data show that a considerable number of cancer patients lose immunity against diphtheria and tetanus after therapy. Compared to ST, patients with ALL lose protective antibody levels more often. Patients with ST reconstituted antibodies after the treatment cessation, while levels in ALL patients remained low.

[HCMV infections after hematopoietic stem cell transplantation--diagnostic methods and importance of viral DNA level monitoring]. / Infekcje ludzkim wirusem cytomegalii po transplantacji macierzystych komórek krwiotwórczych ­ metody diagnostyczne i znaczenie monitorowania poziomu DNA wirusa

HCMV infection is very common. The virus infects 30-90% of population. In immunocompromised patients effective elimination of the virus by immune system is limited by immunosuppressive therapy. Active hCMV infection after HSCT can lead to severe posttransplant complications, graft failure or even death. In addition to direct effects of hCMV infection the virus can cause indirect effects in transplant recipients such as increased immunosuppression or GvHD development/progression. Laboratory diagnostic of hCMV infections after HSCT is now routinely used. Fast and sensitive molecular methods that detect hCMV genetic material are found particularly useful. Quantitative methods, such as R-T PCR, enable identification of patients at high risk of developing hCMV disease and fast employment of appropriate prophylaxis or treatment. Moreover it allows precise monitoring of treatment efficiency and facilitates therapy - related decisions. In last years pre-emptive therapy, which depends on viral load molecular monitoring, significantly reduced morbidity and mortality of active hCMV infections in HSCT recipients. Selective prophylaxis approach enables reduction of patients treated with toxic antiviral therapy which is associated with delayed restoration of virus - specific immune response. Occurrence of symptomatic hCMV disease is still associated with high mortality among HSCT recipients. HCMV infection diagnosis requires further development. Quantitative methods should be unified and optimized.

Utility of quantitative EBV DNA measurements in cerebrospinal fluid for diagnosis and monitoring of treatment of central nervous system EBV-associated post-transplant lymphoproliferative disorder after allogenic hematopoietic stem cell transplantation.

BACKGROUND: Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disorder (PTLD) after hematopoietic stem cell transplantation (HSCT) is a rare but life- threatening condition. Despite routine EBV DNA-emia monitoring in blood, central nervous system involvement of the disease is still associated with diagnostic difficulties and poor outcome. CASE REPORT: We describe a 17-year-old female patient with severe aplastic anemia who developed central nervous system EBV-associated PTLD after matched unrelated allo-HSCT. EBV DNA concentration in cerebrospinal fluid was initially tested due to central nervous system-related symptoms. The sample was found to be highly EBV DNA-positive. Using quantitative real-time polymerase chain reaction (PCR) measurements, therapy efficiency was monitored until complete remission of the EBV-associated PTLD. CONCLUSIONS: The case report illustrates the high utility of quantitative real-time PCR EBV measurements in cerebrospinal fluid for rapid diagnosis and therapy monitoring of central nervous system EBV-associated PTLDs after allo-HSCT.

[Epstein-Barr virus infection - life cycle, methods of diagnosis, associated diseases]. / Zakazenia EBV - cykl zyciowy, metody diagnostyki, chorobotwórczosc.

Epstein-Barr virus (EBV) is a ubiquitous virus that infects about 90­95% of the adult population. EBV establishes life-long latent persistence. The virus is found to be the major cause of infectious mononucleosis but it has also been associated with development of endemic Burkitt's lymphoma. Result of EBV infection is the most common complication in patients after transplantation which is a post-transplant lymphoproliferative disease. Strong associations between EBV infection and Hodgkin's lymphoma, nasopharyngeal carcinoma, gastric carcinoma and carcinomas derived from smooth muscle tissue also exist. There is a hypothesis that there is an association between EBV infection and autoimmune and allergic diseases. EBV is a Herpesvirus family member; its genetic material has dsDNA form. There are two strains of EBV: A and B. The only host for EBV is human with target cells: B cells and epithelial cells. The life cycle of EBV consists of lytic and latent phases. In the latent phase three different patterns of gene expression are possible. Due to some circumstances EBV can undergo reactivation, which is an important issue in transplantology. The main methods of diagnosis of EBV infections are serological methods that detect certain specific antibodies and recently more popular molecular biological methods such as PCR or in situ hybridization.