Melatonin Functions in Plants
Melatonin helps protect plants from both biotic and this type of stress that includes drought, salinity, and heat.
Abiotic stress
What is the newly identified melatonin receptor in Arabidopsis
CAND2/PMTR1
Melatonin can change gene activity in plants. What is the term for turning genes on or off?
Gene expression
How do plants coordinate their growth?
Hormones
These antioxidant enzymes are commonly upregulated by melatonin during stress.
SOD, CAT, and POD
To be considered a plant hormone, a molecule typically must have a known biosynthesis pathway, receptor, and this kind of chain.
A signal transduction chain
Melatonin can regulate genes responsible for biosynthesizing this green pigment.
Chlorophyll
What is auxin important for?
Cellular elongation and regulating cell growth
Name one plant species in which melatonin has been shown to help during cold stress.
Cucumber
The similarity of melatonin to this classic plant hormone originally prompted researchers to study its hormonal potential.
Auxin (Indole - 3 - acetic acid)
What is asymmetric regulation?
Melatonin regulates hormone paths, but hormones do not regulate melatonin paths
Hormone function is often studied by experimenting in what?
Mutants (eg arabidopsis)
What was the main takeaway from Weeda et al Reseacrh?
Different concentration of melatonin can have certain affects on gene expression
Melatonin influences hormone signaling by regulating the biosynthesis of these two key plant hormones (example cucumber seeds)
ABA and gibberellins
When plants are stressed, melatonin turns on genes that help control this harmful molecule made by cells.
Reactive oxygen species (ROS)
What does ABA do and what happens in ABA mutant seeds
ABA is an anti growth hormone which promotes dormancy.
Mutant of ABA would cause germination immediately
What cellular structures are one of the original sites of melatonin biosynthesis in both plants and animals.
Mitochondria and chloroplasts
Name 1 reasons why melatonin is argued to be more than just a hormone.
gene regulatory functions or pleiotropic effects
Under salt stress, melatonin promotes seed germination by downregulating this ABA biosynthesis gene.
NCED2
What is Gibberellin and where is it made?
The growth promoting hormone (cell division and elongation). Produced at the root and shoot tips