In plants, growth can be mediated by what is frequently referred to as \"auxin-
ID: 210392 • Letter: I
Question
In plants, growth can be mediated by what is frequently referred to as "auxin- induced transcription" of genes critical to growth. This terminology was derived from experiments demonstrating that the addition of auxin leads to an increase in the expression of genes responsible for growth. However, since auxin is not a transcription factor and cannot directly activate transcription, how does it regulate gene activity? In the signaling of cells to initiate growth a host of genes designated immediate early genes become activated to initiate the growth process. What would happen to the the expression of these immediate early genes if Elk-1 was not able to to be dephosphorylated and why? Cytokine receptors frequently form dimers upon ligand binding, and these can be heterodimers or homodimers. Explain how this ability of the receptors to form different combinations of dimers allows three unique cytokines, each with a unique action, to arise from only two cytokine receptorsExplanation / Answer
Answers:-
1. Auxin control most aspects of the plant growth by regulating genome expression.
Expression of auxin-responsive genes involves
- interactions among auxin-responsive DNA sequence elements
- transcription factors
- trans-acting transcriptional repressors. Transcriptional output from these auxin signaling complexes is regulated by proteasome-mediated degradation that is triggered by interaction with auxin receptor-E3 ubiquitin ligases such SCF(TIR1).
Auxin signaling components are conserved throughout land plant evolution and have proliferated and specialized to control specific developmental processes.