Breeding for carrot resistance to Alternaria dauci without compromising taste

Developing carrot varieties highly resistant to Alternaria dauci is a top priority for breeders. Meanwhile, consumers are increasingly demanding as regards final product quality, particularly taste. Bitterness is one of the five common taste sensations, but it is rejected by most carrot consumers. Therefore, providing tools for efficient plant breeding of resistant, low bitter carrots would be helpful. While resistance QTLs (rQTLs) have already been identified for carrot resistance to A. dauci, the genetic control and mapping of the metabolites involved in bitterness perception have not been addressed so far. We identified the metabolites most involved in bitterness by combining chemical and sensory analyses of a set of resistant and susceptible carrot genotypes grown in different environments. We evaluated their genetic control and heritability in a segregating F2:3 population over 2 years of field trials and searched for colocalizations between rQTLs and metabolite QTLs (mQTLs) to evaluate the link between bitterness and resistance traits. Our results suggest that it is possible to increase resistance while favoring low bitter varieties by selecting genomic regions involved in the expression of one or the other trait and counter-selecting others when r- and mQTL colocalization is unfavorable

La phytoalexine '6-méthoxymélleine' est-t-elle impliquée dans les mécanismes de résistance de la carotte à Alternaria dauci, agent de la brûlure foliaire ?

Cell wall integrity is crucial for fungal growth, development and stress survival. In yeast, Slt2 MAP kinase and calcineurin signaling pathways monitor cell wall repair during stress and development. MPS1, the M. grisea SLT2 orthologue, is essential for cell wall repair and for appressorium mediated penetration into host plants (Xu 1998 PNAS 95:12713). In yeast, Slt2 activates the transcription factors Rlm1, Swi4 and Swi6, while calcineurin activates Crz1. Genes orthologous to yeast CRZ1, MPS1,Cell wall integrity is crucial for fungal growth, development and stress survival. In yeast, Slt2 MAP kinase and calcineurin signaling pathways monitor cell wall repair during stress and development. MPS1, the M. grisea SLT2 orthologue, is essential for cell wall repair and for appressorium mediated penetration into host plants (Xu 1998 PNAS 95:12713). In yeast, Slt2 activates the transcription factors Rlm1, Swi4 and Swi6, while calcineurin activates Crz1. Genes orthologous to yeast CRZ1, MPS1, RLM1, SWI4, and SWI6 genes were identified in M. grisea genome. Swi4 and Swi6 interact with Mps1 in yeast two hybrid assays. Deletion mutants were constructed by targeted gene replacement in M. grisea. Delta-mps1 mutants displayed an abnormal mycelial growth (no aerial hyphae), did not sporulate, and were nonpathogenic on plants as reported. Delta-crz1, delta-rlm1, delta-swi6 mutants have a normal mycelial growth and sporulation rates similar to wild type. Of these three mutants, only delta-Rlm1 displays a highly reduced pathogenicity on barley and rice (-98%, lesion number). Delta-mps1 mutants are highly sensitive to nikkomycin Z (chitin synthase inhibitor), CFW (disorganization of cell wall) and aculeacine (glucan synthase inhibitor), while delta-crz1 and delta-rlm1 mutant are only mildly hypersensitive to Nikkomycin, and delta-swi6 mutant is only slightly hypersensitive to CFW. These studies suggest that the transcription factors controlled by Mps1 are either functionally redundant or specialized in the control of specific target genes

Therapeutic management of intestinal fibrosis induced by radiation therapy: from molecular profiling to new intervention strategies et vice et versa

Chronic toxicities of locoregional and systemic oncological treatments commonly develop in long-term cancer survivors. Amongst these toxicities, post-radiotherapeutic complications alter patient's quality of life. Reduction of exposure of normal tissues can be achieved by optimization of radiotherapy. Furthermore, understanding of the fibrogenic mechanisms has provided targets to prevent, mitigate, and reverse late radiation-induced damages. This mini-review shows how (i) global molecular studies using gene profiling can provide tools to develop new intervention strategies and (ii) how successful clinical trials, conducted in particular with combined pentoxifylline-vitamin E, can take benefice of biological and molecular evidences to improve our understanding of fibrogenic mechanisms, enhance the robustness of proposed treatments, and lead ultimately to better treatments for patient's benefice

Death, treatment decisions and the permanent vegetative state: evidence from families and experts

Some brain injured patients are left in a permanent vegetative state, i.e., they have irreversibly lost their capacity for consciousness but retained some autonomic physiological functions, such as breathing unaided. Having discussed the controversial nature of the permanent vegetative state as a diagnostic category, we turn to the question of the patients’ ontological status. Are the permanently vegetative alive, dead, or in some other state? We present empirical data from interviews with relatives of patients, and with experts, to support the view that the ontological state of permanently vegetative patients is unclear: such patients are neither straightforwardly alive nor simply dead. Having defended this view from counter-arguments we turn to the practical question as to how these patients ought to be treated. Some relatives and experts believe it is right for patients to be shifted from their currently unclear ontological state to that of being straightforwardly dead, but many are concerned or even horrified by the only legally sanctioned method guaranteed to achieve this, namely withdrawal of clinically assisted nutrition and hydration. A way of addressing this distress would be to allow active euthanasia for these patients. This is highly controversial; but we argue that standard objections to allowing active euthanasia for this particular class of permanently vegetative patients are weakened by these patients’ distinctive ontological status

Antibiotics resisdues in milk

Background: The microbiological quality of raw milk is relatively a new subject that interest more actors of milk production in Algeria. Until now, the raw milk collected presented a high rate of microbial contamination, prejudicial for human consumption and dairy processing. Objective: The aim of this study is to assess the hygienic and sanitary quality of raw milk produced throughout three segments where milk is handled in Tizi Ouzou area (Algeria). Methodology: For this, 174 samples of raw milk were collected throughout farms, collectors and local markets and submitted for microbiological analysis. Results: The results of this study showed that microbial contamination of raw milk increase along the dairy chain. The mean log10 of TBC at farm level was 6.73±0.25 log10 CFU mL–1. This value increase to reach a load of 6.81±0.19 and 7.2±1.05 log10 CFU mL–1 at collection centers and market point