Most asexual species of fungi have either lost sexuality recently, or they experience recombination by cryptic sexual reproduction. Verticillium dahliae is a plant-pathogenic, ascomycete fungus with ...no known sexual stage, even though related genera have well-described sexual reproduction. V. dahliae reproduces mitotically and its population structure is highly clonal. However, previously described discrepancies in phylogenetic relationships among clonal lineages may be explained more parsimoniously by recombination than mutation; therefore, we looked for evidence of recombination within and between clonal lineages. Genotyping by sequencing was performed on 141 V. dahliae isolates from diverse geographic and host origins, resulting in 26,748 single-nucleotide polymorphisms (SNPs). We found a strongly clonal population structure with the same lineages as described previously by vegetative compatibility groups (VCGs) and molecular markers. We detected 443 recombination events, evenly distributed throughout the genome. Most recombination events detected were between clonal lineages, with relatively few recombinant haplotypes detected within lineages. The only three isolates with mating type MAT1-1 had recombinant SNP haplotypes; all other isolates had mating type MAT1-2. We found homologs of eight meiosis-specific genes in the V. dahliae genome, all with conserved or partially conserved protein domains. The extent of recombination and molecular signs of sex in (mating-type and meiosis-specific genes) suggest that V. dahliae clonal lineages arose by recombination, even though the current population structure is markedly clonal. Moreover, the detection of new lineages may be evidence that sexual reproduction has occurred recently and may potentially occur under some circumstances. We speculate that the current clonal population structure, despite the sexual origin of lineages, has arisen, in part, as a consequence of agriculture and selection for adaptation to agricultural cropping systems.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
HIV stigmatization and discrimination (S&D) remain global health concerns for people at risk for or living with HIV. However, few studies have examined Latina/x/os' health in the context of multiple ...systems of oppression targeting their identities, including anti-immigrant prejudice.Despite evidence that Latina/x/o immigrants in the United States have better health outcomes than non-Latina/x/o Whites, advantages are lost over time. HIV S&D generate barriers to accessing services along the HIV care continuum for Latina/x/os.1 Undocumented Latina/ x/o immigrants experience unique factors that shape their health before, during, and after migration,2 including S&D and sociopolitical marginalization (e.g., state-sanctioned discrimination, condemnation as criminals, underpayment for work) as well as structural barriers to accessing HIV services (e.g., denial of care, cultural/language incompetency). Unsurprisingly, undocumented Latina/x/o people living with HIV enter care with more advanced disease than documented individuals.3Intersectional frameworks are needed to illuminate and alter or eliminate interlocking systems of oppression. These systems include sexism (assumption that men are superior to women), classism (belief that social or economic status determines a person's value), ableism (belief that able-bodied individuals are superior to individuals with disabilities), racism (belief that Whites are superior to those of other races/ethnicities), colorism (belief that a lighter skin tone is superior to a darker skin tone), heterosexism (assumption that heterosexuality is the only normal and natural expression of sexuality), ageism (belief that younger people are superior to older people), and transprejudice (negative valuing and stereotyping of individuals whose appearance or identity does not conform to social expectations or conventional conceptions of gender). Here we focus on heterosexism, ageism, and transprejudice to exemplify ways in which intersectional S&D affect Latina/ x/o immigrants.
Studies of adults who experienced sexual orientation change efforts (SOCE) have documented a range of health risks. To date, there is little research on SOCE among adolescents and no known studies of ...parents' role related to SOCE with adolescents. In a cross-sectional study of 245 LGBT White and Latino young adults (ages 21-25), we measured parent-initiated SOCE during adolescence and its relationship to mental health and adjustment in young adulthood. Measures include being sent to therapists and religious leaders for conversion interventions as well as parental/caregiver efforts to change their child's sexual orientation during adolescence. Attempts by parents/caregivers and being sent to therapists and religious leaders for conversion interventions were associated with depression, suicidal thoughts, suicidal attempts, less educational attainment, and less weekly income. Associations between SOCE, health, and adjustment were much stronger and more frequent for those reporting both attempts by parents and being sent to therapists and religious leaders, underscoring the need for parental education and guidance.
Lesbian, gay, bisexual, and transgender (LGBT) youth and young adults are known to have compromised physical and mental health, and family rejection has been found to be an important risk factor. Yet ...few studies have examined the positive role that support from parents, friends, and the community have for LGBT young adults. In a cross-sectional study of 245 LGBT non-Latino White and Latino young adults (ages 21-25) in the United States, sexuality-related social support was examined in association with measures of adjustment in young adulthood. Family, friend, and community support were strong predictors of positive outcomes, including life situation, self-esteem, and LGBT esteem. However, family acceptance had the strongest overall influence when other forms of support were considered. Implications for the unique and concurrent forms of social support for LGBT youth and young adult adjustment are discussed.
Past research documents that both adolescent gender nonconformity and the experience of school victimization are associated with high rates of negative psychosocial adjustment. Using data from the ...Family Acceptance Project's young adult survey, we examined associations among retrospective reports of adolescent gender nonconformity and adolescent school victimization due to perceived or actual lesbian, gay, bisexual, or transgender (LGBT) status, along with current reports of life satisfaction and depression. The participants included 245 LGBT young adults ranging in age from 21 to 25 years. Using structural equation modeling, we found that victimization due to perceived or actual LGBT status fully mediates the association between adolescent gender nonconformity and young adult psychosocial adjustment (i.e., life satisfaction and depression). Implications are addressed, including specific strategies that schools can implement to provide safer environments for gender-nonconforming LGBT students.
Little is known about how adolescents cope with minority stressors related to sexual orientation. This study examined 245 lesbian, gay, and bisexual (LGB) young adult's (ages 21-25) retrospective ...reports of coping in response to LGB minority stress during adolescence (ages 13-19) to test the reliability and validity of a measure of minority stress coping. Further, the study examined associations between LGB minority stress coping and young adult psychosocial adjustment and high school attainment. Validation and reliability was found for three minority stress coping strategies: LGB-specific strategies (e.g., involvement with LGBT organizations), alternative-seeking strategies (e.g., finding new friends), and cognitive strategies (e.g., imagining a better future). LGB-specific strategies were associated with better psychosocial adjustment and greater likelihood of high school attainment in young adulthood, whereas alternative-seeking and cognitive-based strategies were associated with poorer adjustment and less likelihood of high school attainment.
Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris, a main threat to global chickpea production, is managed mainly by resistant cultivars whose efficiency is curtailed by Fusarium oxysporum f. ...sp. ciceris races.
We characterized compatible and incompatible interactions by assessing the spatial-temporal pattern of infection and colonization of chickpea cvs. P-2245, JG-62 and WR-315 by Fusarium oxysporum f. sp. ciceris races 0 and 5 labeled with ZsGreen fluorescent protein using confocal laser scanning microscopy.
The two races colonized the host root surface in both interactions with preferential colonization of the root apex and subapical root zone. In compatible interactions, the pathogen grew intercellularly in the root cortex, reached the xylem, and progressed upwards in the stem xylem, being the rate and intensity of stem colonization directly related with the degree of compatibility among Fusarium oxysporum f. sp. ciceris races and chickpea cultivars. In incompatible interactions, race 0 invaded and colonized 'JG-62' xylem vessels of root and stem but in 'WR-315', it remained in the intercellular spaces of the root cortex failing to reach the xylem, whereas race 5 progressed up to the hypocotyl. However, all incompatible interactions were asymptomatic.
The differential patterns of colonization of chickpea cultivars by Fusarium oxysporum f. sp. ciceris races may be related to the operation of multiple resistance mechanisms.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Many lesbian, gay, bisexual, and transgender (LGBT) adolescents disclose their sexual and/or gender identities to peers at school. Disclosure of LGBT status is linked with positive psychosocial ...adjustment for adults; however, for adolescents, "coming out" has been linked to school victimization, which in turn is associated with negative adjustment. This study investigates the associations among adolescent disclosure of LGBT status to others at school, school victimization, and young adult psychosocial adjustment using a sample of 245 LGBT young adults (aged 21-25 years, living in California). After accounting for the association between school victimization and later adjustment, being out at high school was associated with positive psychosocial adjustment in young adulthood. Results have significant implications for training of school-based health and mental health providers, education and guidance for parents and caregivers, fostering positive development of LGBT youth, and developing informed school policies and educational practices.
BACKGROUND: Adolescent school victimization due to lesbian, gay, bisexual, or transgender (LGBT) status is commonplace, and is associated with compromised health and adjustment. Few studies have ...examined the long‐term implications of LGBT school victimization for young adult adjustment. We examine the association between reports of LGBT school victimization and young adult psychosocial health and risk behavior.
METHODS: The young adult survey from the Family Acceptance Project included 245 LGBT young adults between the ages of 21 and 25 years, with an equal proportion of Latino and non‐Latino White respondents. A 10‐item retrospective scale assessed school victimization due to actual or perceived LGBT identity between the ages of 13 and 19 years. Multiple regression was used to test the association between LGBT school victimization and young adult depression, suicidal ideation, life satisfaction, self‐esteem, and social integration, while controlling for background characteristics. Logistic regression was used to examine young adult suicide attempts, clinical levels of depression, heavy drinking and substance use problems, sexually transmitted disease (STD) diagnoses, and self‐reported HIV risk.
RESULTS: Lesbian, gay, bisexual, and transgender‐related school victimization is strongly linked to young adult mental health and risk for STDs and HIV; there is no strong association with substance use or abuse. Elevated levels of depression and suicidal ideation among males can be explained by their high rates of LGBT school victimization.
CONCLUSIONS: Reducing LGBT‐related school victimization will likely result in significant long‐term health gains and will reduce health disparities for LGBT people. Reducing the dramatic disparities for LGBT youth should be educational and public health priorities.
Wild olive trees, namely oleaster, are considered the ancestor of cultivated olive and a unexplored source of genetic variability that might contain important traits of agronomic and biotechnological ...interest. The longevity and genetic diversity of oleasters may have favoured selection of specific and well adapted rhizosphere microbial populations that can constitute unique reservoirs of microbial antagonists of Verticillium dahliae, the main soilborne fungal pathogen of olive worldwide. The objective of this present study was to determine the structure and diversity of bacterial communities in the rhizosphere and endosphere of oleaster from 11 havens in Cádiz and Córdoba provinces of Andalusia, southern Spain. To carry out the study we used a multiphasic approach. First, the occurrence and diversity of rhizosphere bacteria was monitored by a cultivation-independent-approach, using fluorescent terminal restriction fragment length polymorphism (FT-RFLP) analyses of amplified 16S rDNA sequences. FT-RFLP patterns revealed a high heterogeneity in the composition of the sampled rhizosphere bacterial communities and suggested the existence of plant genotype-site-specific communities, with each oleaster haven being a unique reservoir of bacterial diversity. Secondly, to investigate the antagonistic potential of these root-associated bacterial populations, a total of 675 bacterial isolates obtained from oleaster rhizosphere and endosphere were screened by dual testing for inhibition of in vitro growth of the highly virulent, olive defoliating pathotype of V. dahliae. Out of 675 tested bacterial isolates, 94 (14%) showed a strong antagonistic activity against a defoliating V. dahliae pathotype. Of the antagonistic bacteria, a slightly lower proportion (12.9% of total bacteria) were inhabitant of the oleaster rhizosphere compared to that in the endosphere (16.5%). The biotechnological potential of those isolates was assessed by in vitro production of different hydrolytic enzymes, indole-1.3-acetic acid (IAA), siderophores, and antimicrobial compounds. Overall, most of bacterial antagonists (58.5 to 78.3%) showed proteolytic, lipolytic, and chitinolytic activity, and produced IAA and siderophores. Finally, analysis of the 16S rDNA gene sequence indicated that most of the 94 bacterial antagonists belong to genera Bacillus (56.4%), Pseudomonas (27.7%), and Paenibacillus (7.4%). Overall, the rhizosphere and endosphere of wild olives were proved as a good reservoir of bacteria antagonists against V. dahliae. Several of those bacteria showing high and broad antagonism potential may therefore be considered for further analyses as promising biocontrol agents against V. dahliae in olive.
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