Water and Temperature Stress Impact Fitness of Acetohydroxyacid Synthase–Inhibiting Herbicide-Resistant Populations of Eastern Black Nightshade (Solanum ptychanthum)

Weed Science ◽  
2011 ◽  
Vol 59 (3) ◽  
pp. 341-348 ◽  
Author(s):  
Jamshid Ashigh ◽  
François J. Tardif
Keyword(s):  
Seed Production ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Stress Conditions ◽  
Acetohydroxyacid Synthase ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Reproductive Ability ◽  
Temperature Regimes ◽  
The Impact

Many substitutions in the herbicide target enzyme acetohydroxyacid synthase (AHAS) confer whole-plant resistance and may reduce plant fitness. This study was done to determine the impact of different watering and temperature regimes on the germination, growth, and seed production of eastern black nightshade populations resistant (R) to AHAS inhibitors as conferred by an Ala205Val substitution in their AHAS. Growth and reproductive ability of four R and four susceptible (S) populations were determined in growth-cabinet and greenhouse studies. The R populations had lower total berry and viable seed production per plant than S under optimal conditions because of slower berry maturation. Seed production of both S and R populations decreased under lower or higher than optimal watering regimes; however, this reduction was more pronounced for the S populations so that seed production was comparable across S and R. The R populations had significantly higher germination and vegetative growth under cooler alternating temperature regimes. Although there were no differences between R and S plants under stress conditions, under optimal growth conditions, the Ala205Val substitution comes at a significant cost in eastern black nightshade. Under optimal growth conditions and in the absence of herbicide selection, S populations should eventually dominate over R; however, the lack of fitness differences under stress conditions could enhance the persistence of the R individuals.

scholarly journals The first study on the impact of osmolytes in whole cells of high temperature-adapted microorganisms

Soft Matter ◽  
2019 ◽  
Vol 15 (41) ◽  
pp. 8381-8391 ◽  
Author(s):  
Marta Salvador-Castell ◽  
Maksym Golub ◽  
Nicolas Martinez ◽  
Jacques Ollivier ◽  
Judith Peters ◽  
...  
Keyword(s):  
High Temperature ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Structural Rearrangements ◽  
Whole Cells ◽  
The Impact

The presence of the osmolyte mannosylglycerate in alive cells of Thermococcus barophilus, a hyperthermophile and piezophile, limits the structural rearrangements of its proteome under the archaeon optimal growth conditions, i.e. 358 K and 40 MPa.

scholarly journals Rpb4p, a Subunit of RNA Polymerase II, Mediates mRNA Export during Stress

2003 ◽  
Vol 14 (7) ◽  
pp. 2744-2755 ◽  
Author(s):  
Marganit Farago ◽  
Tal Nahari ◽  
Christopher Hammel ◽  
Charles N. Cole ◽  
Mordechai Choder
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Mrna Export ◽  
Optimal Growth ◽  
Cellular Responses ◽  
Growth Conditions ◽  
Stress Conditions ◽  
Major Mechanism ◽  
A Subunit

Changes in gene expression represent a major mechanism by which cells respond to stress. We and other investigators have previously shown that the yeast RNA polymerase II subunit Rpb4p is required for transcription under various stress conditions, but not under optimal growth conditions. Here we show that, in addition to its role in transcription, Rpb4p is also required for mRNA export, but only when cells are exposed to stress conditions. The roles of Rpb4p in transcription and in mRNA export can be uncoupled genetically by specific mutations in Rpb4p. Both functions of Rpb4p are required to maintain cell viability during stress. We propose that Rpb4p participates in the cellular responses to stress at the interface of the transcription and the export machineries.

scholarly journals Path Analysis of Tomato Yield Components in Relation to Competition with Black and Eastern Black Nightshade

1994 ◽  
Vol 119 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Milton E. McGiffen ◽  
Dan James Pantone ◽  
John B. Masiunas
Keyword(s):  
Population Density ◽  
Path Analysis ◽  
Yield Components ◽  
Management Practices ◽  
Marketable Yield ◽  
Erroneous Conclusion ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Tomato Yield ◽  
The Impact

Path analysis is a statistical method for determining the magnitude and direction of multiple effects on a complex process. We used path analysis to assess 1) the impact of black nightshade(Solarium nigrum L.) or eastern black nightshade(Solarium ptycanthum Dun.) competition on the yield components of `Heinz 6004' processing tomato (Lycopersicon esculentum Mill.) and 2) the relationship between tomato yield components and total and marketable yield. Either black or eastern black nightshade was interplanted with tomatoes at population densities from 0 to 4.8/m2. Path analysis revealed that increasing weed population density led directly to fewer green and total fruit per plant, two components of marketable yield. However, the percentage of culls per plant and fruit weight were not affected by nightshade population density. Using correlation coefficients alone would have lead to the erroneous conclusion that the percentage of culls did not affect marketable yield; our path analysis demonstrated that decreasing the percentage of culls through breeding or cultural practices will strongly affect marketable yield. The total number of fruit was the most important yield component in determining total and marketable yields per plant. Breeding and management practices that maximize fruit set, increase maturity at harvest, and decrease the percentage of culls would be expected to increase marketable yield.

scholarly journals GFP plasmid-induced defects in Salmonella invasion depend on plasmid architecture, not protein expression

Microbiology ◽  
2009 ◽  
Vol 155 (2) ◽  
pp. 461-467 ◽  
Author(s):  
Leann Clark ◽  
Isabel Martinez-Argudo ◽  
Tom J. Humphrey ◽  
Mark A. Jepson
Keyword(s):  
Gene Expression ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Gfp Expression ◽  
Antibiotic Resistance Marker ◽  
Chloramphenicol Resistance ◽  
Cultured Epithelial Cells ◽  
Induced Defects ◽  
The Impact ◽  
Plasmid Carriage

We have investigated the impact of plasmids and GFP expression on invasion of cultured epithelial cells by Salmonella enterica Typhimurium strain SL1344. The invasiveness of SL1344 carrying plasmids derived from pBR322, encoding promoterless GFP or constitutively expressed rpsM-GFP, was compared under optimal growth conditions with that of SL1344(pBR322), unmodified SL1344 and a strain with chromosome-integrated rpsM-GFP. The strain carrying pBR322 exhibited normal invasion, but the presence of modified plasmids impaired invasiveness, and impairment was exacerbated by plasmid-encoded chloramphenicol resistance (CmR). Using a different antibiotic resistance marker, kanamycin (KmR), did not impair invasiveness. Despite the effect of plasmid-encoded CmR, the strain containing chromosomally encoded GFP, also carrying a CmR gene, was as invasive as the wild-type. To investigate the mechanism by which plasmid carriage decreases invasion, we monitored SPI-1 gene expression using prgH promoter activity as an index of SPI-1 activity. An SL1344 strain with a chromosome-integrated prgH : : gfp reporter construct exhibited lower GFP expression during exponential phase when carrying plasmids incorporating CmR or gfp, mirroring invasion data. These data provide evidence that suppression of SPI-1 gene expression is a major factor in the loss of invasiveness associated with plasmid carriage. Our findings also indicate that some plasmids, especially those carrying CmR , should be used with caution, as virulence traits and gene expression may be affected by their presence. Integration of reporter proteins into the bacterial chromosome, however, appears to circumvent the adverse effects observed with plasmids.

An Ala205Val Substitution in Acetohydroxyacid Synthase of Eastern Black Nightshade (Solanum ptychanthum) Reduces Sensitivity to Herbicides and Feedback Inhibition

Weed Science ◽  
2007 ◽  
Vol 55 (6) ◽  
pp. 558-565 ◽  
Author(s):  
Jamshid Ashigh ◽  
François J. Tardif
Keyword(s):  
Amino Acid ◽  
Specific Activity ◽  
Feedback Inhibition ◽  
Acetohydroxyacid Synthase ◽  
Susceptible Population ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Branched Chain Amino Acid ◽  
Resistant Population ◽  
Branched Chain

Twelve populations of eastern black nightshade from different locations in Ontario are resistant to imazethapyr. This study aimed at determining the molecular basis of resistance in these populations and the activity of the resistant acetohydroxyacid synthase (AHAS) enzyme compared to that of the sensitive AHAS in response to different herbicides and branched-chain amino acid concentration. The results of partialAHASsequencing indicated that all resistant populations had a cytosine331to thymine substitution coding for an alanine205to valine substitution.In vitroAHAS enzyme assays of one resistant population showed that the specific activity of the resistant enzyme was 56% less than that of the susceptible enzyme. AHAS from the resistant population was 72-, 70-, and 64-fold less sensitive than that of the susceptible population to imazethapyr, imazamox, and primisulfuron, respectively. Furthermore, the resistant enzyme was less sensitive to feedback inhibition from branched-chain amino acids compared to the susceptible enzyme. Results confirmed that resistance in resistant populations of eastern black nightshade was conferred by target-site modification and that the Ala205Val substitution alters the kinetics and regulation of branched-chain amino acid biosynthesis.

Estimating Yield Losses of Tomatoes (Lycopersicon esculentum) Caused by Nightshade (Solanumspp.) Interference

Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Susan E. Weaver ◽  
Nancy Smits ◽  
Chin S. Tan
Keyword(s):  
Lycopersicon Esculentum ◽  
Seed Production ◽  
Unit Area ◽  
Dry Weight ◽  
Hyperbolic Model ◽  
Yield Losses ◽  
Eastern Black Nightshade ◽  
Solanum Ptycanthum ◽  
Black Nightshade ◽  
Tomato Yield

Reductions in yields of processing tomatoes (Lycopersicon esculentumMill. ‘H2653’ and ‘Earlirouge′) caused by interference from eastern black nightshade (Solanum ptycanthumDun. # SOLPT) and hairy nighthsade (S. sarrachoidesSendt. # SOLSA) were estimated for transplanted and seeded tomatoes at two locations in southern Ontario. Tomato yield losses were significantly greater in seeded than in transplanted tomatoes. Stomatal conductance and transpiration rates of seeded tomatoes decreased more rapidly with increased nightshade density than did those of transplanted tomatoes. Percent yield losses also differed between sites. Seeded tomatoes grown at high density in twin rows (33 300 and 45 000 plants/ha) had higher yields and lower percent yield losses than did tomatoes grown at low density in single rows (12 500 to 22 500 plants/ha). Nightshade dry weight and seed production decreased per plant but increased per unit area with increasing nightshade density. Nightshade dry weights and seed production did not vary with site or method of tomato establishment. A hyperbolic model provided an excellent fit to data on both tomato yield losses and nightshade seed production as a function of nightshade density.

scholarly journals Impact of uORFs in mediating regulation of translation in stress conditions

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Simone G. Moro ◽  
Cedric Hermans ◽  
Jorge Ruiz-Orera ◽  
M. Mar Albà
Keyword(s):  
Large Fraction ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Ribosome Profiling ◽  
Stress Conditions ◽  
Translational Repression ◽  
Translational Efficiency ◽  
Ribosome Stalling ◽  
Regulation Of Translation ◽  
Translational Arrest

Abstract Background A large fraction of genes contains upstream ORFs (uORFs) in the 5′ untranslated region (5’UTR). The translation of uORFs can inhibit the translation of the main coding sequence, for example by causing premature dissociation of the two ribosomal units or ribosome stalling. However, it is currently unknown if most uORFs are inhibitory or if this activity is restricted to specific cases. Here we interrogate ribosome profiling data from three different stress experiments in yeast to gain novel insights into this question. Results By comparing ribosome occupancies in different conditions and experiments we obtain strong evidence that, in comparison to primary coding sequences (CDS), which undergo translational arrest during stress, the translation of uORFs is mostly unaffected by changes in the environment. As a result, the relative abundance of uORF-encoded peptides increases during stress. In general, the changes in the translational efficiency of regions containing uORFs do not seem to affect downstream translation. The exception are uORFs found in a subset of genes that are significantly up-regulated at the level of translation during stress; these uORFs tend to be translated at lower levels in stress conditions than in optimal growth conditions, facilitating the translation of the CDS during stress. We find new examples of uORF-mediated regulation of translation, including the Gcn4 functional homologue fil1 and ubi4 genes in S. pombe. Conclusion We find evidence that the relative amount of uORF-encoded peptides increases during stress. The increased translation of uORFs is however uncoupled from the general CDS translational repression observed during stress. In a subset of genes that encode proteins that need to be rapidly synthesized upon stress uORFs act as translational switches.

scholarly journals Translation of a leaderless reporter is robust during exponential growth and well sustained during stress conditions in Mycobacterium tuberculosis

2021 ◽  
Author(s):  
A. D. Grabowska ◽  
N. Andreu ◽  
T. Cortes
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Translational Regulation ◽  
Molecular Mechanisms ◽  
Growth Arrest ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Stress Conditions ◽  
Shine Dalgarno Sequence ◽  
Overall Ratio

Abstract Mycobacterium tuberculosis expresses a large number of leaderless mRNA transcripts; these lack the 5’ leader region, which usually contains the Shine-Dalgarno sequence required for translation initiation in bacteria. In M. tuberculosis, transcripts encoding proteins with secondary adaptive functions are predominantly leaderless and the overall ratio of leaderless to Shine-Dalgarno transcripts significantly increases during growth arrest, suggesting that leaderless translation might be important during persistence in the host. However, whether these two types of transcripts are translated with differing efficiencies during stress conditions that induce growth arrest and during optimal growth conditions, is unclear. Here, using bioluminescent reporter strains, we detect robust leaderless translation during exponential in vitro growth and we show that leaderless translation is more stable than Shine-Dalgarno translation during adaptation to stress conditions. Upon entrance into nutrient starvation and after nitric oxide exposure, leaderless translation is significantly less affected by the stress than Shine-Dalgarno translation. Similarly, during the early stages of infection of macrophages, the levels of leaderless translation are more stable than those of Shine-Dalgarno translation. These results suggest that leaderless translation may offer an advantage in the physiology of M. tuberculosis. Identification of the molecular mechanisms underlying this translational regulation may provide insights into persistent infection.

Germination of Cutleaf Groundcherry (Physalis angulata), Smooth Groundcherry (Physalis virginiana), and Eastern Black Nightshade (Solanum ptycanthum)

Weed Science ◽  
1987 ◽  
Vol 35 (1) ◽  
pp. 58-62 ◽  
Author(s):  
Craig E. Thomson ◽  
William W. Witt
Keyword(s):  
Moisture Stress ◽  
Seedling Vigor ◽  
Viable Seed ◽  
Eastern Black Nightshade ◽  
Solanum Ptycanthum ◽  
Black Nightshade ◽  
Temperature Regimes ◽  
Physalis Angulata ◽  
Alternating Temperature ◽  
Substrate Ph

Factors that govern the germination of cutleaf groundcherry (Physalis angulataL. # PHYAN), smooth groundcherry [Physalis virginianavar.subglabrata(Mackenz. and Bush) Waterfall # PHYSU], and eastern black nightshade (Solanum ptycanthumDun. # SOLPT) were evaluated. Maximum germination of all three species occurred at a constant 30 C or alternating temperature regimes that included 30 C. Seed of all species germinated in light and dark, but germination was reduced in the dark. Germination and seedling vigor of all species decreased as substrate pH decreased. Cutleaf groundcherry seed were slightly less sensitive than seed of other species to simulated moisture stress. All species produced 90% or more viable seed by 8 weeks after anthesis.

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