Use of the additive main effects and multiplicative interaction model in QTL mapping for adaptation in barley

The additive main effects and multiplicative interaction (AMMI) model has emerged as a powerful analytical tool for genotype x environment studies. The objective of the present study was to assess its value in quantitative trait locus (QTL) mapping. This was done through the analysis of a large two-way table of genotype-by-environment data of barley (Hordeum vulgare L.) grain yields, where the genotypes constituted a genetic population suitable for mapping studies. Grain yield data of 150 doubled haploid lines derived from the Steptoe x Morex cross, and the two parental lines, were taken by the North American Barley Genome Mapping Project (NABGMP) at 16 environments throughout the barley production areas of the USA and Canada. Four regions of the genome were responsible for most of the differential genotypic expression across environments. They accounted for approximately 50% of the genotypic main effect and 30% of the genotype x environment interaction (GE) sums of squares. The magnitude and sign of AMMI scores for genotypes and sites facilitate inferences about specific interactions. The parallel use of classification (cluster analysis of environments) and ordination (principal component analysis of GE matrix) techniques allowed most of the variation present in the genotype x environment matrix to be summarized in just a few dimensions, specifically four QTLs showing differential adaptation to four clusters of environments. Thus, AMMI genotypic scores, when the genotypes constituted a population suitable for QTL mapping, could provide an adequate way of resolving the magnitude and nature of QTL x environment interactions.Ignacio Romagosa was on sabbatical leave from the University of Lleida and the Institut de Recerca i Tecnologia Agroalimentàries, Lleida, Spain, when this study was conducted     

Factors affecting production of COS and CS2 in Leucaena and Mimosa species

Carbon disulfide (CS₂) and carbonyl sulfide (COS) are colorless, foul-smelling, volatile sulfur compounds with biocidal properties. Some plants produce CS₂ or COS or both. When used as an intercrop or forecrop, these plants may have agronomic potential in protecting other plants. Most of the factors which affect production of these plant-generated organic sulfides are unknown. We determined the effects of sulfate concentration, plant age, nitrogen fixation, drought stress, root injury (through cutting), and undisturbed growth on COS production in Leucaena retusa or Leucaena leucocephala and the effect of some of these factors on CS₂ production in Mimosa pudica. In addition, we determined if organic sulfides were produced in all Leucaena species. When L. retusa and M. pudica seedlings were grown in a plant nutrient medium with different sulfate concentrations (50 to 450 mg SL^-1), COS or CS₂ from crushed roots generally increased with increasing sulfate concentration. COS production was highest (74 ng mg^-1 dry root) for young L. retusa seedlings and declined to low amounts (<5 ng mg^-1 dry root) for older seedlings. Nitrogen fixation reduced the amounts of COS or CS₂ produced in L. leucocephala and M. pudica. Under conditions of undisturbed growth, root cutting, or drought stress, no COS production was detected in 4-to 8-weeks-old L. retusa plants. COS or CS₂ or both was obtained from crushed roots or shoots of all 13 known Leucaena species.     

Dietary Iodine Affected the GSH-Px to Regulate the Thyroid Hormones in Thyroid Gland of Rex Rabbits

Iodine (I) is an essential trace element that can influence animal health and productivity. In this study, we investigated the effects of dietary iodine on the antioxidant indices of organ (liver and thyroid gland) and messenger RNA (mRNA) expression of glutathione peroxidase (GSH-Px) in Rex rabbits. A total of 120 4-month-old Rex rabbits (2235.4 ± 13.04 g BW) were divided into four equal groups, and their diets were supplemented with iodine (0, 0.2, 2, or 4 mg/kg dry matter (DM)). The iodine concentration in basal diet (control group) was 0.36 mg/kg DM. In most of measured parameters, supplemental iodine exerted no significant effect. Growth and slaughter performance and organ weight were not influenced significantly by iodine supplementation. Serum T₃ was significantly lower in 2-mg I group than in 0.2 and 4-mg I groups (P < 0.05). Superoxide dismutase (SOD), GSH-Px, methane dicarboxylic aldehyde (MDA), and thyroperoxidase (TPO) in the serum and liver were not influenced (P > 0.05). Conversely, serum catalase (CAT) was significantly reduced (P < 0.05). In the thyroid, GSH-Px was higher in the 2-mg I group than in the 0.2- and 4-mg I groups (P < 0.05). RT-PCR results showed that the mRNA expression level of GSH-Px in the liver was not significantly influenced (P > 0.05). In the thyroid gland, the mRNA expression level of GSH-Px was higher in the 2-mg I group than in the 4-mg I group (P < 0.05), which agreed with the activity of GSH-Px. In conclusion, iodine supplementation exerted no effect on the performance and antioxidant capacity of the body, but dietary iodine influenced serum T₃ or GSH-Px in the thyroid gland. Thus, on the basis of serum T₃ and GSH-Px levels in the thyroid gland, we hypothesized that GSH-Px secretion was increased by adding dietary iodine in the thyroid, which may inhibit the H₂O₂ generation and further influence the thyroid hormone synthesis.     

Enterocytozoon bieneusi Genotypes in Yaks (Bos grunniens) and Their Public Health Potential

Enterocytozoon bieneusi, the most frequently diagnosed microsporidian species in humans, is also identified in a wide range of animals. To date, few data are available on E. bieneusi in yaks (Bos grunniens). In this study, we examined the occurrence and genotype identity of E. bieneusi in yaks in four counties in Qinghai Province of China. Of 327 fecal specimens examined by nested PCR analysis of the ribosomal internal transcribed spacer, 23 (7.0%) were E. bieneusi‐positive. DNA sequence analysis of the PCR products revealed the presence of five distinct genotypes: three Group 2 genotypes previously reported in cattle as well as humans (BEB4, I and J) and two novel genotypes (CHN11 and CHN12) belonging to the large zoonotic group (Group 1). Data of the study suggest that these animals could be potential reservoirs for human E. bieneusi infection.     

Coexpression of the High Molecular Weight Glutenin Subunit 1Ax1 and Puroindoline Improves Dough Mixing Properties in Durum Wheat (Triticum turgidum L. ssp. durum)

Wheat end-use quality mainly derives from two interrelated characteristics: the compositions of gluten proteins and grain hardness. The composition of gluten proteins determines dough rheological properties and thus confers the unique viscoelastic property on dough. One group of gluten proteins, high molecular weight glutenin subunits (HMW-GS), plays an important role in dough functional properties. On the other hand, grain hardness, which influences the milling process of flour, is controlled by Puroindoline a (Pina) and Puroindoline b (Pinb) genes. However, little is known about the combined effects of HMW-GS and PINs on dough functional properties. In this study, we crossed a Pina-expressing transgenic line with a 1Ax1-expressing line of durum wheat and screened out lines coexpressing 1Ax1 and Pina or lines expressing either 1Ax1 or Pina. Dough mixing analysis of these lines demonstrated that expression of 1Ax1 improved both dough strength and over-mixing tolerance, while expression of PINA detrimentally affected the dough resistance to extension. In lines coexpressing 1Ax1 and Pina, faster hydration of flour during mixing was observed possibly due to the lower water absorption and damaged starch caused by PINA expression. In addition, expression of 1Ax1 appeared to compensate the detrimental effect of PINA on dough resistance to extension. Consequently, coexpression of 1Ax1 and PINA in durum wheat had combined effects on dough mixing behaviors with a better dough strength and resistance to extension than those from lines expressing either 1Ax1 or Pina. The results in our study suggest that simultaneous modulation of dough strength and grain hardness in durum wheat could significantly improve its breadmaking quality and may not even impair its pastamaking potential. Therefore, coexpression of 1Ax1 and PINA in durum wheat has useful implications for breeding durum wheat with dual functionality (for pasta and bread) and may improve the economic values of durum wheat.     

p62 links the autophagy pathway and the ubiqutin–proteasome system upon ubiquitinated protein degradation

The ubiquitin–proteasome system (UPS) and autophagy are two distinct and interacting proteolytic systems. They play critical roles in cell survival under normal conditions and during stress. An increasing body of evidence indicates that ubiquitinated cargoes are important markers of degradation. p62, a classical receptor of autophagy, is a multifunctional protein located throughout the cell and involved in many signal transduction pathways, including the Keap1–Nrf2 pathway. It is involved in the proteasomal degradation of ubiquitinated proteins. When the cellular p62 level is manipulated, the quantity and location pattern of ubiquitinated proteins change with a considerable impact on cell survival. Altered p62 levels can even lead to some diseases. The proteotoxic stress imposed by proteasome inhibition can activate autophagy through p62 phosphorylation. A deficiency in autophagy may compromise the ubiquitin–proteasome system, since overabundant p62 delays delivery of the proteasomal substrate to the proteasome despite proteasomal catalytic activity being unchanged. In addition, p62 and the proteasome can modulate the activity of HDAC6 deacetylase, thus influencing the autophagic degradation.     

Identifying optimal groundwater remediation strategies through a simulation-based PROMETHEE-TOPSIS approach: An application to a naphthalene-contaminated site

Abstract

The aim of this paper is to develop a simulation-aided PROMETHEE-TOPSIS approach for the selection of the most desirable groundwater remediation strategies. The combination methods enables a careful evaluation of the identified remediation alternatives in which their strong and weak points can be detected and a ranking is provided which facilitates the final selection for the decision-maker. The capabilities and effectiveness of the developed method are illustrated through a case study on the remedial alternative selection for a naphthalene contaminated site in Anhui, China. Four attributes (i.e., total pumping rate, total cost, mean residual contaminant concentration and maximum excess life time cancer risk) for fifty remedial alternatives in each duration are considered and analytic hierarchy process is used to determine the weight of attributes importance. The results demonstrates that the developed method could help decision makers obtain the useful ranking information strategies that covering a variety of decision-relevant remediation options, which is beneficial for public health and environmental protection.     

食用菌厉眼蕈蚊Lycoriella ingenua在温度逆境下的存活率

以食用菌重要害虫-厉眼蕈蚊属的Lycoriella ingenua为研究对象,研究了不同逆境温度下各虫态存活率的差异。结果表明温度对不同虫态存活率的影响存在显著性差异。成虫和蛹对高温具有一定适应性,卵对高温的适应性最低但具有一定的低温耐受力。在35-40℃高温下,相同暴露时间,各虫态的存活率随温度的升高而降低,但成虫的存活率均高于其它虫态。38℃下全部死亡的暴露时间分别为:成虫48 h,蛹24 h,幼虫12 h,卵2h。在40℃达到全部死亡的暴露时间分别为:成虫24 h、蛹12 h、卵和幼虫0.5 h。低温处理下,各虫态随着暴露时间的延长存活率逐渐降低。5℃低温下,相同暴露时间,成虫存活率均高于其它虫态,但在0℃低温下暴露24 h后全部死亡,显著高于其它虫态;幼虫在低温下取食活动减弱,5℃下暴露24 h后停止取食,相同暴露时间下随着温度的降低存活率下降;蛹对0℃的耐受力高于成虫和幼虫,暴露4 h后可以正常羽化,48 h后全部死亡;卵对短时间的低温具有一定耐受力,但随着暴露时间的延长存活率降低幅度大。