Adaptation and Divergence in Stressful Environments

Author(s):  
Michael Travisano
2013 ◽  
Author(s):  
Ted Scharf ◽  
Charles Vaught ◽  
Kathleen Kowalski-Trakofler ◽  
Ross Pastel ◽  
Donald Elisburg ◽  
...  

2021 ◽  
pp. 153537022110312
Author(s):  
Kenneth S Ramos ◽  
Pasano Bojang ◽  
Emma Bowers

LINE-1 retrotransposon, the most active mobile element of the human genome, is subject to tight regulatory control. Stressful environments and disease modify the recruitment of regulatory proteins leading to unregulated activation of LINE-1. The activation of LINE-1 influences genome dynamics through altered chromatin landscapes, insertion mutations, deletions, and modulation of cellular plasticity. To date, LINE-1 retrotransposition has been linked to various cancer types and may in fact underwrite the genetic basis of various other forms of chronic human illness. The occurrence of LINE-1 polymorphisms in the human population may define inter-individual differences in susceptibility to disease. This review is written in honor of Dr Peter Stambrook, a friend and colleague who carried out highly impactful cancer research over many years of professional practice. Dr Stambrook devoted considerable energy to helping others live up to their full potential and to navigate the complexities of professional life. He was an inspirational leader, a strong advocate, a kind mentor, a vocal supporter and cheerleader, and yes, a hard critic and tough friend when needed. His passionate stand on issues, his witty sense of humor, and his love for humanity have left a huge mark in our lives. We hope that that the knowledge summarized here will advance our understanding of the role of LINE-1 in cancer biology and expedite the development of innovative cancer diagnostics and treatments in the ways that Dr Stambrook himself had so passionately envisioned.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zebus Sehar ◽  
Noushina Iqbal ◽  
M. Iqbal R. Khan ◽  
Asim Masood ◽  
Md. Tabish Rehman ◽  
...  

AbstractEthylene plays a crucial role throughout the life cycle of plants under optimal and stressful environments. The present study reports the involvement of exogenously sourced ethylene (as ethephon; 2-chloroethyl phosphonic acid) in the protection of the photosynthetic activity from glucose (Glu) sensitivity through its influence on the antioxidant system for adaptation of wheat (Triticum aestivum L.) plants under salt stress. Ten-day-old plants were subjected to control and 100 mM NaCl and treated with 200 µl L−1 ethephon on foliage at 20 days after seed sowing individually or in combination with 6% Glu. Plants receiving ethylene exhibited higher growth and photosynthesis through reduced Glu sensitivity in the presence of salt stress. Moreover, ethylene-induced reduced glutathione (GSH) production resulted in increased psbA and psbB expression to protect PSII activity and photosynthesis under salt stress. The use of buthionine sulfoximine (BSO), GSH biosynthesis inhibitor, substantiated the involvement of ethylene-induced GSH in the reversal of Glu-mediated photosynthetic repression in salt-stressed plants. It was suggested that ethylene increased the utilization of Glu under salt stress through its influence on photosynthetic potential and sink strength and reduced the Glu-mediated repression of photosynthesis.


Author(s):  
Sara Altowaiji ◽  
Rakahn Haddadin ◽  
Priscilla Campos ◽  
Shannon Sorn ◽  
Lizbeth Gonzalez ◽  
...  

Chemistry laboratory experiences provide students the opportunity to engage all three domains of learning: psychomotor, cognitive and affective. However, they are often stressful environments where students are expected to quickly learn new laboratory techniques, and collect data in a short amount of time. In principle, providing additional preparation activities should help students be better prepared to successfully complete the lab. These activities should lead to more meaningful interactions with the lab instructor and better performance on lab outcomes. In this study, we report the usefulness and effectiveness of online preparation activities for students that include video lectures demonstrating the labs that the students will participate in, and preparation questions that mimic data analysis for the lab. These online prelab activities were implemented in the second semester general chemistry laboratory at a large Hispanic serving institution in the southwestern United States. Over three semesters, students enrolled in this course were surveyed using the Meaningful Learning in the Laboratory Instrument (MLLI) to assess their lab expectations as well as author generated post-lab surveys to assess the usefulness of the prelab activities. Additionally, lab instructors were surveyed on their perception of the efficacy of the additional preparation activities. Findings suggest that both students and instructors agree that having access to these materials as a part of a portfolio of resources, including the lab manual, help them better prepare for the lab. Although students’ expectations on the cognitive domain decreased after a semester of instruction, questions related to comfort with lab equipment show improvements in the affective domain for students with access to the additional preparation activities. Lastly we found that both students and instructors see a lot of value and benefits in having these types of prelab activities available as a way to help prepare students for the upcoming laboratory sessions. In general, the potential benefits that prelab activities had on students outweigh the modest effort to create these materials.


2014 ◽  
Vol 74 (3) ◽  
pp. 744-749 ◽  
Author(s):  
GR Demetrio ◽  
FF Coelho ◽  
MEA Barbosa

Body size is one of the most important factors regarding herbaceous perennial plants life-histories, and several fitness components of these organisms are related to size. Clonal plants show distinct kinds of reproduction and can develop offspring by sexual or asexual ways. We aimed to understand how body size affects Comanthera nivea (Eriocaulaceae) sexual reproduction and to verify how clonal growth is related to flower head production in this species. We sampled 600 rosettes in rupestrian grasslands and performed linear regression analysis between body size and number of produced flower heads. We also compared the flower head production between isolated rosettes and rosettes within clones. Our results showed that body size was significantly related, but explained only a small part of flower head production. The flower head production was higher in rosettes within clones than in isolated ones. The clones presented a rosette or a small group of rosettes that concentrated the sexual reproduction. Clonality was positively associated with sexual reproduction. Clonality can represent an important way of allowing the persistence of plants by sexual reproduction in markedly seasonal stressful environments. The cases of clonality enhancing the sexual reproduction must be considered and put in focus on reproductive biology research.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yu Jinqiu ◽  
Li Bing ◽  
Song Tingting ◽  
He Jinglei ◽  
KongLing Zelai ◽  
...  

Oat is an annual gramineous forage grass with the remarkable ability to survive under various stressful environments. However, understanding the effects of high altitude stresses on oats is poor. Therefore, the physiological and the transcriptomic changes were analyzed at two sites with different altitudes, low (ca. 2,080 m) or high (ca. 2,918 m), respectively. Higher levels of antioxidant enzyme activity, reactive oxygen and major reductions in photosynthesis-related markers were suggested for oats at high altitudes. Furthermore, oat yields were severely suppressed at the high altitude. RNA-seq results showed that 11,639 differentially expressed genes were detected at both the low and the high altitudes in which 5,203 up-regulated and 6,436 down-regulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment tests were conducted and a group of major high altitude-responsive pigment metabolism genes, photosynthesis, hormone signaling, and cutin, suberine and wax biosynthesis were excavated. Using quantitative real-time polymerase chain response, we also confirmed expression levels of 20 DEGs (qRT-PCR). In summary, our study generated genome-wide transcript profile and may be useful for understanding the molecular mechanisms of Avena sativa L. in response to high altitude stress. These new findings contribute to our deeper relevant researches on high altitude stresses and further exploring new candidategenes for adapting plateau environment oat molecular breeding.


2022 ◽  
Vol 12 ◽  
Author(s):  
Peiguo Yuan ◽  
Kiwamu Tanaka ◽  
B. W. Poovaiah

Calcium (Ca2+) signaling in plant cells is an essential and early event during plant-microbe interactions. The recognition of microbe-derived molecules activates Ca2+ channels or Ca2+ pumps that trigger a transient increase in Ca2+ in the cytoplasm. The Ca2+ binding proteins (such as CBL, CPK, CaM, and CML), known as Ca2+ sensors, relay the Ca2+ signal into down-stream signaling events, e.g., activating transcription factors in the nucleus. For example, CaM and CML decode the Ca2+ signals to the CaM/CML-binding protein, especially CaM-binding transcription factors (AtSRs/CAMTAs), to induce the expressions of immune-related genes. In this review, we discuss the recent breakthroughs in down-stream Ca2+ signaling as a dynamic process, subjected to continuous variation and gradual change. AtSR1/CAMTA3 is a CaM-mediated transcription factor that represses plant immunity in non-stressful environments. Stress-triggered Ca2+ spikes impact the Ca2+-CaM-AtSR1 complex to control plant immune response. We also discuss other regulatory mechanisms in which Ca2+ signaling activates CPKs and MAPKs cascades followed by regulating the function of AtSR1 by changing its stability, phosphorylation status, and subcellular localization during plant defense.


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