Genetic interactions matter more in less-optimal environments: a Focused Review of â€œPhenotype uniformity in combined-stress environments has a different genetic architecture than in single-stress treatmentsâ€ (Makumburage and Stapleton, 2011)

The yielding and fracture characteristics of Zircaloy-2 as a function of stress state were investigated at room temperature through the medium of thin-walled cylindrical specimens under internal pressure and axial tension. Stress states from uniaxial longitudinal tension to uniaxial tangential tension were examined. Two tests at elevated temperature were performed at a single stress ratio. It was found that the fracture ductility lessened with increasing biaxiality. A minimum in ductility was found at balanced biaxial tension where the fracture ductility, as expressed by the effective strain, was 29 per cent. The yielding and plastic flow properties were found to be highly anisotropic. Two methods were used to express the plastic flow data: a graphical approach and a theoretical analysis based on a theory proposed by R. Hill, either one of which is suitable to express the flow properties of Zircaloy-2 under various states of combined stress.

Download Full-text

Study on Effect of Heavy Metal and Rare Earth Metal on Soil Activities

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.356-360.1126 ◽

2011 ◽

Vol 356-360 ◽

pp. 1126-1130

Author(s):

Jin Xia Nie ◽

Ping Huang ◽

Da Chao Zhang

Keyword(s):

Heavy Metal ◽

Rare Earth ◽

Public Awareness ◽

Earth Metal ◽

Ecological Indicators ◽

Garden Soil ◽

Combined Stress ◽

Soil Urease ◽

Single Stress ◽

Soil Cd

In recent years, as public awareness on environmental problems increasing, soil pollutions are received more and more attention. Choosing a suburban garden soil as objective, adding exogenous heavy metal cadmium (Cd) and rare-earth element lanthanide (La) in the soil, Cd/La single stress and combined stress on soil urease and catalase were studied. The results showed that under Cd/La single or combined processing, both soil urease and catalase activities decrease while the concentration increases. With the incubation time extending, soil urease activities first increase and then decrease, and soil catalase first reduce then increase. Cd/La single and combined process has obvious inhibition on soil urease and catalase. At the same concentration, the inhibition degree to enzyme activity was Cd>Cd, La combined> La, and the inhibition of soil urease was higher than that of catalase. Soil urease and catalase showed a significantly negative correlation under different treatments. So setting soil urease and catalase as ecological indicators to soil heavy metal and rare earth elements pollution is feasible.

Download Full-text

Genetic architecture of a mutation’s expressivity and penetrance

10.1101/2020.04.03.024547 ◽

2020 ◽

Author(s):

Rachel Schell ◽

Martin N. Mullis ◽

Takeshi Matsui ◽

Ryan Foree ◽

Ian M. Ehrenreich

Keyword(s):

Saccharomyces Cerevisiae ◽

Genome Stability ◽

Genetic Architecture ◽

Genetic Interactions ◽

Diverse Populations ◽

Major Contributor ◽

Complex Genetics ◽

Reference Strains ◽

Lines Of Evidence

AbstractMutations often have different effects in genetically distinct individuals. Epistasis between mutations and segregating loci is known to be a major contributor to these background effects, but the architecture of these genetic interactions remains largely unknown. Here, we characterize how segregating loci in a cross of two Saccharomyces cerevisiae strains impact growth following the deletion of the histone deacetylase HOS3. The functions of HOS3 are not well understood and historically its deletion has shown little effect on reference strains. However, we map two loci that genetically interact with HOS3 and each other to produce a broad range of responses to the deletion, including near inviability. Although these interactions explain nearly all of the deletion’s expressivity, their penetrance depends on a liability threshold involving at least 11 additional nuclear and mitochondrial loci. Multiple lines of evidence imply the deletion uncovers genetically complex changes in translation and genome stability in the mitochondria, suggesting a novel connection between Hos3-mediated deacetylation and the mitochondria. These results provide a valuable example of the complicated and unexpected mechanisms that can cause background effects in genetically diverse populations, and show how characterization of background effects can provide new insights into gene function.One Sentence SummaryComplex genetics shape a mutation’s penetrance and expressivity.

Download Full-text

Plant growth regulators ameliorate or exacerbate abiotic and biotic stress effects on Zea mays kernel weight in a genotype-specific manner

10.1101/088195 ◽

2016 ◽

Author(s):

Lauren Stutts ◽

Yishi Wang ◽

Ann E. Stapleton

Keyword(s):

Zea Mays ◽

Plant Growth ◽

Plant Growth Regulators ◽

Growth Regulators ◽

Biotic Stress ◽

Abiotic And Biotic Stress ◽

Combined Stress ◽

Chemical Treatments ◽

Significant Difference ◽

Stress Environments

ABSTRACTPlant growth regulators have documented roles in plant responses to single stresses. In combined-stress environments, plants display novel genetic architecture for growth traits and the response to growth regulators is unclear. We investigated the role of plant growth regulators in combined-stress responses in Zea mays. Twelve maize inbreds were exposed to all combinations of the following stressors: drought, nitrogen, and density stress. Chemical treatments were utilized to alter balances of the hormones abscisic acid, gibberellic acid, and brassinosteroids. We found a significant difference between the seed weights of plants given different chemical treatments after accounting for differences in genotype and stress environments. We conclude that plant growth regulators have targets in combined-stress response pathways in Zea mays.HIGHLIGHTPlant growth regulators can ameliorate effects of combinations of abiotic and biotic stress in maize, in certain genotypes and under specific stress conditions.

Download Full-text