Tools and Techniques - Effects of Plant Growth Regulators

We have discussed about the "effect of auxins". In this section we shall discuss the methodology being followed in hormone studies:

a) Observations: The knowledge about role of light or temperature in flowering and germination of avena coleoptile curvature or apical dominance or 0th r phenomenon like senescence resulted out of empirical studies during the late 19th and early parts of the 20th centuries.

b) The fact that a hormone like substance is involved was realized through simple experimental studies like removal of supposed sources of hormone production like spices, leaves etc. and observing this effect on growth and development of plants.

c) The chemical nature of hormones was then elucidated through biochemical techniques of isolation, purification and structural studies using techniques like i) chromatography, ii) chemical purification, iii) studies of chemical properties etc.

d) In vitro studies of cells, tissues and organs over the last 60 years contributed to our knowledge the effects of hormones in more detail.

e) Studies with transcription and translation inhibitors yielded and still are throwing new light on hormone action at the molecular level.

f) Isolation of proteins that bind to hormones called 'receptors' is throwing focus on 'perception of signals' at cell level.

g) Studies on linkages between respiration and hormone action are increasingly stressing the role of phosphorylation, energy requirement and the role of other membrane bound proteins.