scholarly journals Mythimna separata herbivory primes maize resistance in systemic leaves

Author(s):  
Saif ul Malook ◽  
Yuxing Xu ◽  
Jinfeng Qi ◽  
Jing Li ◽  
Lei Wang ◽  
...  

Abstract Biotic and abiotic cues can trigger priming in plants, which enables plants to respond to subsequent challenge with stronger and/or faster responses. It is well known that herbivory activates defense-related responses in systemic leaves. However, little is known about whether insect feeding activates priming in systemic leaves. To determine whether and how herbivory induces priming in maize systemic leaves, a combination of insect bioassays, phytohormone and defense metabolite quantification, and genetic and transcriptome analyses were performed. Actual and simulated Mythimna separata herbivory in maize local leaves primed the systemic leaves for enhanced accumulation of jasmonic acid and benzoxazinoids and increased resistance to M. separata. Activation of priming in maize systemic leaves depends on both the duration of simulated herbivory and perception of M. separata oral secretions in the local leaves, and genetic analysis indicated that jasmonic acid and benzoxazinoids mediate the primed defenses in systemic leaves. Consistently, in response to simulated herbivory, the primed systemic leaves exhibited a large number of genes that were uniquely regulated or showed further up- or down-regulation compared with the non-primed systemic leaves. This study provides new insight into the regulation and ecological function of priming in maize.

2018 ◽  
Vol 15 (142) ◽  
pp. 20180157 ◽  
Author(s):  
Karen M. Page ◽  
Ruben Perez-Carrasco

Ring oscillators are biochemical circuits consisting of a ring of interactions capable of sustained oscillations. The nonlinear interactions between genes hinder the analytical insight into their function, usually requiring computational exploration. Here, we show that, despite the apparent complexity, the stability of the unique steady state in an incoherent feedback ring depends only on the degradation rates and a single parameter summarizing the feedback of the circuit. Concretely, we show that the range of regulatory parameters that yield oscillatory behaviour is maximized when the degradation rates are equal. Strikingly, this result holds independently of the regulatory functions used or number of genes. We also derive properties of the oscillations as a function of the degradation rates and number of nodes forming the ring. Finally, we explore the role of mRNA dynamics by applying the generic results to the specific case with two naturally different degradation timescales.


2020 ◽  
Author(s):  
Soyoung Park ◽  
Jozef Dingemans ◽  
Madison Gowett ◽  
Karin Sauer

<p>In <em>Pseudomonas aeruginosa</em>, the orphan two-component sensor SagS contributes to both, the transition to biofilm formation and to biofilm cells gaining their heightened tolerance to antimicrobials. However, little is known about the identity of the signals or conditions sensed by SagS to induce the switch to the sessile, drug tolerant mode of growth. Using a modified Biolog phenotype assay to screen for compounds that modulate attachment in a SagS-dependent manner, we identified glucose-6-phosphate to enhance attachment in a manner dependent on the glucose-6-phosphate concentration and SagS. The stimulatory effect was not limited to the attachment as glucose-6-phosphate likewise enhanced biofilm formation. We show that exposure to glucose-6-phosphate results in decreased swarming motility but increased cellular c-di-GMP levels in biofilms. Genetic analysis indicated that the diguanylate cyclase NicD is an activator of biofilm formation and is not only required for enhanced biofilm formation in response to glucose-6-phosphate but also interacts with SagS. Our findings indicate glucose-6-phosphate to likely mimic a signal or conditions sensed by SagS to activate its motile-sessile switch function. Additionally, our findings provide new insight into the interfaces between the ligand-mediated TCS signaling pathway and c-di-GMP levels.</p>


2020 ◽  
Author(s):  
Huiping Zhang ◽  
Kun Xiao ◽  
Shengchao Ma ◽  
Long Xu ◽  
Ning Ding ◽  
...  

Abstract Background: Increasing evidences supported that elevated homocysteine (Hcy) levels contribute to cell apoptosis is implicated in the pathogenesis of liver injury, it correlates with liver disease severity. However, the underlying mechanism of apoptosis in Hcy-mediated liver injury remains obscure. Results: In this study, we found that homocysteine increases ER stress-mediated apoptosis and aggravates liver injury through up-regulation of PSMD10 expression in cbs+/- mice mice fed with high methionine diet and hepatocytes treated with homocysteine in vitro. Knockdown of PSMD10 expression remarkably reduced ER stress or apoptosis-associated protein in hepatocytes exposed to homocysteine. Moreover, bioinformatics analysis revealed that PSMD10 is a potential target gene of miR-212-5p, and luciferase reporter assay also confirmed that miR-212-5p negatively regulated PSMD10 expression by direct binding to its 3’-UTR regions. Subsequently, over-expression of miR-212-5p inhibited ER stress-mediated hepatocytes apoptosis though targeting PSMD10, all of which were abrogated by knockdown of miR-212-5p expression. Further study showed that the interaction between PSMD10 and GRP78 accelerated ER stress-mediated hepatic apoptosis induced by homocysteine. Conclusion: Taken together, these results demonstrated that down-regulation of miR-212-5p facilitates homocysteine-induced hepatocytes apoptosis via targeting PSMD10, which provides novel insight into the mechanism of homocysteine induced apoptosis in liver injury.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maciej Karpowicz ◽  
Magdalena Świsłocka ◽  
Joanna Moroz ◽  
Łukasz Sługocki

AbstractThe taxonomic status of the genus Bythotrephes Leydig (Crustacea: Cladocera) has been debated since the second half of the XIX century. The most widespread view of recent decades has been that Bythotrephes is a monotypic genus, which was support by preliminary molecular data. However, the recent detailed morphological revision of this genus clearly distinguishes at least seven species. Therefore, we performed a multi-lake survey in Central Europe to give new insight into the taxonomic status of Bythotrephes by combining genetic analysis with traditional morphology-based taxonomy. Based on the morphology we identified two species in Central Europe, B. brevimanus and B. lilljeborgi, as well as hybrid forms. For the genetic analysis, we used newly obtained 113 sequences of mtDNA COI gene of the 535-bp length Bythotrephes from Central Europe and sequences downloaded from GenBank. There were no significant differences between all analyzed sequences, which supports the hypothesis that Bythotrephes is a monotypic genus, with only one highly polymorphic species. On the other hand, the results of our work could point out that the COI gene is insufficient to evaluate the taxonomic status of Bythotrephes. Nonetheless, we have identified 29 new haplotypes of mtDNA COI, and one which was the same as the haplotype found in North America and Finland. Furthermore, this haplotype was the source variant from which most other haplotypes were derived.


2019 ◽  
Author(s):  
Mark Zander ◽  
Mathew G. Lewsey ◽  
Natalie M. Clark ◽  
Lingling Yin ◽  
Anna Bartlett ◽  
...  

AbstractUnderstanding the systems-level actions of transcriptional responses to hormones provides insight into how the genome is reprogrammed in response to environmental stimuli. Here, we investigate the signaling pathway of the hormone jasmonic acid (JA), which controls a plethora of critically important processes in plants and is orchestrated by the transcription factor MYC2 and its closest relatives in Arabidopsis thaliana. We generated an integrated framework of the response to JA that spans from the activity of master and secondary-regulatory transcription factors, through gene expression outputs and alternative splicing to protein abundance changes, protein phosphorylation and chromatin remodeling. We integrated time series transcriptome analysis with (phospho)proteomic data to reconstruct gene regulatory network models. These enable us to predict previously unknown points of crosstalk from JA to other signaling pathways and to identify new components of the JA regulatory mechanism, which we validated through targeted mutant analysis. These results provide a comprehensive understanding of how a plant hormone remodels cellular functions and plant behavior, the general principles of which provide a framework for analysis of cross-regulation between other hormone and stress signaling pathways.


Genetics ◽  
2014 ◽  
Vol 197 (1) ◽  
pp. 175-192 ◽  
Author(s):  
Jian Cao ◽  
Julie Ni ◽  
Wenxiu Ma ◽  
Vanessa Shiu ◽  
Luis A. Milla ◽  
...  

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