A systems study of the effect of osmotic stress on hormone crosstalk and growth in Arabidopsis thaliana roots

Understanding the mechanisms regulating root development under drought conditions is an important question for plant biology and world agriculture. This thesis examines the effect of osmotic stress on the plant hormones abscisic acid (ABA), cytokinin and ethylene responses and how they mediate auxin transport, distribution and root growth via PIN proteins Root growth is reduced under osmotic stress, and ABA responses increase. Root growth can be rescued by inhibiting ABA biosynthesis, indicating its critical role in the regulation of growth under stress. There was also a reduction in cytokinin signalling under stress. The inhibition of root growth under osmotic stress does not require ethylene signalling, however auxin can rescue growth. Osmotic stress also modulates auxin transporter levels, particularly PIN1, which regulates auxin transport to the root tip. As PIN1 levels are reduced under stress in an ABA-dependent manner, overriding the ethylene effect on PIN1 levels, and auxin responses decrease under stress, I present the hypothesis that ABA is limiting auxin transport to the root under stress to reduce growth. However, the interplay between ABA, ethylene, cytokinin and auxin is tissue-specific, with the result that PIN1 and PIN2 differentially respond to osmotic stress. Combining experimental analysis with extensive literature searches allowed the systematic construction of interaction networks, incorporating the known interactions between the hormones and stress. This network analysis reveals that ABA regulates root growth under osmotic stress conditions via interactions with cytokinin, ethylene and auxin demonstrating complicated non-linear relationships and providing a framework for further kinetic modelling. Kinetic modelling (using differential equations to simulate these interactions) of ethylene and ABA effects on PIN1 levels reveals that the hormones most likely act on the same pathway to regulate PIN1 levels. The work presented here provides novel insights into how root growth is regulated by hormones under drought and osmotic stress conditions

Every Flower that blossoms : Easter Song

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How Attachment Styles Affect Our Perception of Daily Activities

Existing research indicates that social functioning (i.e., emotional motives, social interaction, relationships, interpersonal goals) is associated with personal attachment style (Locke, 2008) and avoidance in emerging adults. Furthermore, attachment styles of individuals can predict daily activities and personal motives (Springstein et al., 2023). While evidence has pointed to interpersonal risk (i.e., physiological safety versus threat) and a sense of security, research has yet to explore these variables in the relationship between attachment styles and helping other individuals in social settings in university students. For our research, we wanted to expand on this past research and test the effects of daily activities and how people perceive these based on their attachment styles. We hypothesized that participants who have an anxious or avoidant attachment style will be less likely to help in perceptive daily social situations than those who have a secure attachment style. The participant sample are 46 introductory psychology students who participated for class credit in SONA. Participants were asked to complete a questionnaire of 10 hypothetical situations of daily activities demonstrated through prosocial Qualtrics. Afterwards, participants were to take an online attachment style questionnaire consisting of 24 questions that will conclude their attachment styles based on research of attachment styles positively influencing external relationships (Natisse et. al. 2022). We found that..

The Minstrel Boy / music by Harry Rowe Shelley; words by Harry Rowe Shelley

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The Lantern Vol. 32, No. 1, January 1965

• The Wise Man • Of Men and Lobsters • Deliberate-Beyond Conception • Villanelle • Villanelle: Interlude • Rune Green Stones • Redemption • John Ten • Torch Ends • The General and the Birdnest • Not Quite Free • Hymn to the Morning • Walking Togetherhttps://digitalcommons.ursinus.edu/lantern/1087/thumbnail.jp