Alterações morfológicas e acúmulo de compostos fenólicos em plantas de sorgo sob estresse de alumínio Changes in morfology and phenolics accumulation in sorghum (Sorghum bicolor (L.) Moench) plants under aluminum stress

Os efeitos do alumínio (Al+3) sobre a morfologia e o acúmulo de compostos fenólicos foram avaliados em duas cultivares de sorgo (Sorghum bicolor (L.) Moench) com tolerância diferencial ao Al+3. As plantas foram mantidas em solução nutritiva durante dez dias, na presença (185 mM) ou na ausência de Al+3. Os ápices radiculares foram coloridos com hematoxilina férrica, sendo a intensidade da coloração observada na presença do Al+3 muito próxima entre as cultivares, o que inviabiliza a aplicação desse teste, isoladamente, para discriminação entre o genótipo sensível e o tolerante ao Al+3. As análises da morfologia externa e interna dos ápices radiculares de plantas tratadas com Al+3 também foram muito similares entre as duas cultivares, não permitindo a utilização dessas características para seleção entre a cultivar sensível e a tolerante. O maior acúmulo de lignina e, principalmente, a menor produção de compostos fenólicos, observados na presença do Al+3 nas raízes das plantas da cultivar tolerante (BR006R), são parâmetros que possibilitam a discriminação das cultivares quanto à tolerância ao Al+3.<br>The Al+3 effects on the morphology and on the phenolics accumulation were evaluated in two sorghum cultivars exhibiting differential tolerance to Al+3. The plants were kept in nutrient solution, for ten days, in the presence (185 mM) or Al+3 absence. The root apexes were colored with ferric hematoxylin, and because the intensity of color development is very similar among evaluated cultivars, the use of this method as a selection parameter for Al+3-tolerance is not indicated. Analyses of superficial and internal morphology from tissues treated with Al+3 also expressed very similar alterations among the two cultivars, not allowing its use for selection between sensitive and Al+3-tolerant genotype. The higher lignin accumulation and, mainly, the lower phenolics production in roots of the BR006R cultivar in Al+3's presence, demonstrated the existence of differential tolerance among cultivars

African-specific alleles modify risk for asthma at the 17q12-q21 locus in African Americans

Background: Asthma is the most common chronic disease in children, occurring at higher frequencies and with more severe disease in children with African ancestry. Methods: We tested for association with haplotypes at the most replicated and significant childhood-onset asthma locus at 17q12-q21 and asthma in European American and African American children. Following this, we used whole-genome sequencing data from 1060 African American and 100 European American individuals to identify novel variants on a high-risk African American–specific haplotype. We characterized these variants in silico using gene expression and ATAC-seq data from airway epithelial cells, functional annotations from ENCODE, and promoter capture (pc)Hi-C maps in airway epithelial cells. Candidate causal variants were then assessed for correlation with asthma-associated phenotypes in African American children and adults. Results: Our studies revealed nine novel African-specific common variants, enriched on a high-risk asthma haplotype, which regulated the expression of GSDMA in airway epithelial cells and were associated with features of severe asthma. Using ENCODE annotations, ATAC-seq, and pcHi-C, we narrowed the associations to two candidate causal variants that are associated with features of T2 low severe asthma. Conclusions: Previously unknown genetic variation at the 17q12-21 childhood-onset asthma locus contributes to asthma severity in individuals with African ancestries. We suggest that many other population-specific variants that have not been discovered in GWAS contribute to the genetic risk for asthma and other common diseases. © 2022, The Author(s).Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Aluminium tolerance in barley (Hordeum vulgare L.): physiological mechanisms, genetics and screening methods

Aluminium (Al) toxicity is one of the major limiting factors for barley production on acid soils. It inhibits root cell division and elongation, thus reducing water and nutrient uptake, consequently resulting in poor plant growth and yield. Plants tolerate Al either through external resistance mechanisms, by which Al is excluded from plant tissues or internal tolerance mechanisms, conferring the ability of plants to tolerate Al ion in the plant symplasm where Al that has permeated the plasmalemma is sequestered or converted into an innocuous form. Barley is considered to be most sensitive to Al toxicity among cereal species. Al tolerance in barley has been assessed by several methods, such as nutrient solution culture, soil bioassay and field screening. Genetic and molecular mapping research has shown that Al tolerance in barley is controlled by a single locus which is located on chromosome 4H. Molecular markers linked with Al tolerance loci have been identified and validated in a range of diverse populations. This paper reviews the (1) screening methods for evaluating Al tolerance, (2) genetics and (3) mechanisms underlying Al tolerance in barley

Cholinesterase Inhibitors for Alzheimer Disease: Multitargeting Strategy based on Anti-Alzheimer's Drugs Repositioning

International audienceIn the brain, acetylcholine (ACh) is regarded as one of the major neurotransmitters. During the advancement of Alzheimer's disease (AD) cholinergic deficits occur and this can lead to extensive cognitive dysfunction and decline. Acetylcholinesterase (AChE) remains a highly feasible target for the symptomatic improvement of AD. Acetylcholinesterase (AChE) remains a highly viable target for the symptomatic improvementin AD because cholinergic deficit is a consistent and early finding in AD. The treatment approach of inhibitingperipheral AChE for myasthenia gravis had effectively proven that AChE inhibition was a reachable therapeutictarget. Subsequently tacrine, donepezil, rivastigmine, and galantamine were developed and approved for thesymptomatic treatment of AD. Since then, multiple cholinesterase inhibitors (ChEIs) have been continued to bedeveloped. These include newer ChEIs, naturally derived ChEIs, hybrids, and synthetic analogues. In this paper,we summarize the different types of ChEIs which are under development and their respective mechanisms ofactions