scholarly journals Evolutionary trade-offs between drought resistance mechanisms across a precipitation gradient in a seasonally dry tropical oak (Quercus oleoides)

2017 ◽  
Vol 37 (7) ◽  
pp. 889-901 ◽  
Author(s):  
Jose A. Ramírez-Valiente ◽  
Jeannine Cavender-Bares
Keyword(s):  
Drought Resistance ◽  
Resistance Mechanisms ◽  
Precipitation Gradient ◽  
Seasonally Dry ◽  
Trade Offs ◽  
Quercus Oleoides

scholarly journals Interactions between the Prophage 919TP and Its Vibrio cholerae Host: Implications of gmd Mutation for Phage Resistance, Cell Auto-Aggregation, and Motility

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2342
Author(s):  
Na Li ◽  
Yigang Zeng ◽  
Bijie Hu ◽  
Tongyu Zhu ◽  
Sine Lo Svenningsen ◽  
...  
Keyword(s):  
Bacterial Pathogen ◽  
Genomic Analysis ◽  
Resistant Mutant ◽  
Resistance Mechanisms ◽  
Phage Resistance ◽  
Comparative Genomic ◽  
Lytic Phage ◽  
O Antigen ◽  
Trade Offs ◽  
Base Pair Deletion

Prophage 919TP is widely distributed among Vibrio cholera and is induced to produce free φ919TP phage particles. However, the interactions between prophage φ919TP, the induced phage particle, and its host remain unknown. In particular, phage resistance mechanisms and potential fitness trade-offs, resulting from phage resistance, are unresolved. In this study, we examined a prophage 919TP-deleted variant of V. cholerae and its interaction with a modified lytic variant of the induced prophage (φ919TP cI-). Specifically, the phage-resistant mutant was isolated by challenging a prophage-deleted variant with lytic phage φ919TP cI-. Further, the comparative genomic analysis of wild-type and φ919TP cI--resistant mutant predicted that phage φ919TP cI- selects for phage-resistant mutants harboring a mutation in key steps of lipopolysaccharide (LPS) O-antigen biosynthesis, causing a single-base-pair deletion in gene gmd. Our study showed that the gmd-mediated O-antigen defect can cause pleiotropic phenotypes, e.g., cell autoaggregation and reduced swarming motility, emphasizing the role of phage-driven diversification in V. cholerae. The developed approach assists in the identification of genetic determinants of host specificity and is used to explore the molecular mechanism underlying phage-host interactions. Our findings contribute to the understanding of prophage-facilitated horizontal gene transfer and emphasize the potential for developing new strategies to optimize the use of phages in bacterial pathogen control.

scholarly journals Comparative transcriptome analysis of genes involved in two peanut varieties under drought stress

2020 ◽  
Author(s):  
Chunji Jiang ◽  
Xinlin Li ◽  
Jixiang Zou ◽  
Jingyao Ren ◽  
Chunyi Jin ◽  
...  
Keyword(s):  
Drought Resistance ◽  
Time Course ◽  
Stomatal Closure ◽  
Resistance Mechanisms ◽  
Oxygen Species ◽  
Tolerance Mechanism ◽  
Physiological Characterization ◽  
Oil Crops ◽  
Differential Expressed Genes ◽  
Transcriptomic Changes

Abstract Background Peanut is one of the most important world oil crops. Peanut qualities and yields are restricted dramatically by abiotic stresses particularly by drought. Therefore, it would be beneficial to gain a comprehensive understanding on regulatory mechanisms of the peanut genomic transcriptional activities responding to drought, and hopefully extracting peanut molecular drought-resistance mechanisms. Results In this study, two peanut varieties NH5 (resistant) and FH18 (sensitive) which showed significantly differential drought-resistance were screened from twenty-three main commercial peanut cultivars and used for physiological characterization and transcriptomic analysis. NH5 leaves showed higher water and GSH contents, faster stomatal closure and lower relative conductivity (REC) than FH18. Under the time-course of 0 h (CK), 4 h (DT1), 8 h (DT2) and 24 h (DT3), drought-treatments tent to exert repressive impacts on peanut transcriptomes since the number of down-regulated differential expressed genes (DEGs) increased with the progression of treatments in both varieties. Conclusions Nevertheless, NH5 seemed to maintain stabler transcriptomic dynamics than FH18. Furthermore, annotations of identified DEGs implicated that signal transduction, elimination of reactive oxygen species, maintenance of cell osmotic potential were key drought-resistance-related pathways. Last, examination of ABA and SA components suggested that the fast stomata closure in NH5 was likely to be mediated through SA rather than ABA signaling. In all, these results have not only provided us comprehensive pictures of peanut drought transcriptomic changes, but also laid a foundation for further identification of the molecular drought tolerance mechanism in peanut and other oil crops.

Evaluation of drought resistance-related traits in durum wheat somaclonal lines selected in vitro

2004 ◽  
Vol 44 (1) ◽  
pp. 27 ◽  
Author(s):  
M. Bajji ◽  
P. Bertin ◽  
S. Lutts ◽  
J-M. Kinet
Keyword(s):  
Durum Wheat ◽  
Somaclonal Variation ◽  
Drought Resistance ◽  
In Vitro Selection ◽  
Culture Media ◽  
Field Studies ◽  
Resistance Mechanisms ◽  
Wide Range ◽  
Triticum Durum Desf

Somaclonal variation associated with in vitro selection has been used as a source of variability to improve drought resistance of 3 durum wheat (Triticum durum Desf.) cultivars (Selbera, Sebou, and Kyperounda). In a previous study, R0 plants with improved drought resistance-related characters were regenerated after selection on culture media containing polyethylene glycol (PEG). This improvement was transmitted to the R1 progeny. The present study analysed the behaviour of the selected tissue culture-derived lines in subsequent R2, R3 and R4�generations. Differences in electrolyte leakage, chlorophyll fluorescence (Fv/Fm), stomatal conductance and days to heading were found between the parental cultivars and most of their in vitro-derived lines. The changes may differ from one cultivar to another. Many promising somaclonal lines still presented improvement for at least 3 of the 4�parameters measured comparatively to initial cultivars. Somaclonal variation thus appears to induce a wide range of modifications among individual components of drought-resistance mechanisms. These improved traits could be valuable if shown to be inherited and to give enhanced agronomic performances in future field studies.

scholarly journals Ectomycorrhizal diversity and community structure in stands of Quercus oleoides in the seasonally dry tropical forests of Costa Rica

2016 ◽  
Vol 11 (12) ◽  
pp. 125007 ◽  
Author(s):  
Nikhilesh S Desai ◽  
Andrew W Wilson ◽  
Jennifer S Powers ◽  
Gregory M Mueller ◽  
Louise M Egerton-Warburton
Keyword(s):  
Community Structure ◽  
Costa Rica ◽  
Tropical Forests ◽  
Seasonally Dry ◽  
Ectomycorrhizal Diversity ◽  
Seasonally Dry Tropical Forests ◽  
Dry Tropical Forests ◽  
Quercus Oleoides

scholarly journals Drought and frost resistance vary between evergreen and deciduous Atlantic Forest canopy trees

2020 ◽  
Vol 47 (9) ◽  
pp. 779
Author(s):  
Débora di Francescantonio ◽  
Mariana Villagra ◽  
Guillermo Goldstein ◽  
Paula I. Campanello
Keyword(s):  
Tree Species ◽  
Forest Canopy ◽  
Resistance Mechanisms ◽  
Stress Factors ◽  
Climate Change Scenarios ◽  
Adaptive Responses ◽  
Deciduous Species ◽  
Evergreen Species ◽  
Transport Efficiency ◽  
Trade Offs

Frost and drought are key stress factors limiting the growth and distribution of tree species. Resistance to stress involves energy costs that may result in trade-offs between different functional traits. Structures or mechanisms that can help to withstand stress imply differences in the carbon economy of the species. Although adaptive responses to frost and drought resistance are usually of a similar nature, they are rarely assessed simultaneously. We investigated these resistance mechanisms in 10 canopy tree species coexisting in the semi-deciduous subtropical forests of northern Argentina. We measured leaf lifespan, anatomical, photosynthetic and water relations traits and performed a thermal analysis in leaves to determined ice nucleation and tissue damage temperatures. Our results showed that evergreen and deciduous species have different adaptive responses to cope with freezing temperatures and water deficits. Evergreen species exhibited cold tolerance, while deciduous species were more resistant to hydraulic dysfunction and showed greater water transport efficiency. Further research is needed to elucidate resistance strategies to stress factors at the whole tree- and stand level, and possible links with hydraulic safety and efficiency among different phenological groups. This will allow us to predict the responses of subtropical forest species to changes in environmental conditions under climate change scenarios.

Life-History Plasticity and Water-Use Trade-Offs Associated with Drought Resistance in a Clade of California Jewelflowers

2020 ◽  
Vol 195 (4) ◽  
pp. 691-704 ◽  
Author(s):  
Ian S. Pearse ◽  
Jessica M. Aguilar ◽  
Sharon Y. Strauss
Keyword(s):  
Life History ◽  
Water Use ◽  
Drought Resistance ◽  
Trade Offs

scholarly journals Transcriptional Network Analysis Reveals Drought Resistance Mechanisms of AP2/ERF Transgenic Rice

2017 ◽  
Vol 8 ◽  
Author(s):  
Hongryul Ahn ◽  
Inuk Jung ◽  
Seon-Ju Shin ◽  
Jinwoo Park ◽  
Sungmin Rhee ◽  
...  
Keyword(s):  
Network Analysis ◽  
Transgenic Rice ◽  
Drought Resistance ◽  
Resistance Mechanisms ◽  
Transcriptional Network

Surviving in semi-arid environments: functional coordination and trade-offs in shrubs from Argentina

IAWA Journal ◽  
2021 ◽  
pp. 1-19
Author(s):  
Natalia Delbón ◽  
Lucía V. Castello ◽  
Alejandro Rios-Villamil ◽  
María T. Cosa ◽  
Laura Stiefkens
Keyword(s):  
Small Diameter ◽  
Leaf Traits ◽  
Human Action ◽  
Survival Strategies ◽  
Arid Environments ◽  
Leaf Trait ◽  
Seasonally Dry ◽  
Trade Offs ◽  
Dry Conditions ◽  
Wood Traits

Abstract Human action has led to an increase in aridification, making water a progressively scarcer resource. In angiosperms, different species resolve this challenge in diverse ways, mainly through modifications of the xylem network, which is responsible for water efficiency and safety. Xerophytes generally show similar characteristics, but exceptions are rather frequent. One possible explanation for this lack of similarity among cohabiting species is that trade-offs and/or functional coordination between their organs occur and shape alternative survival strategies. Studying species that inhabit a common area can help to identify key traits that determine those diverse strategies and to predict which species might tolerate further environmental change. We here examined the morpho-anatomical wood and bark traits of a group of species that live in a seasonally dry environment in Argentina. In a previous study, we described the leaf traits of these species and we thus aim to complement our findings and outline their strategies to manage water deficits. Our results show that there are different degrees of xeromorphism within this group. Clear xeromorphic traits, such as high vessel frequency and small diameter, were found in most species. However, some presented traits that were appropriate for mesic environments. An overview of leaf and wood traits indicates that the absence of a typical xeric characteristic in the wood might be compensated by the presence of a xeric leaf trait, and vice versa. Collectively, these trait combinations allow these species to survive in dry conditions and could influence their tolerance to increasing aridity.

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