Additional free energy for the formation of phosphodiester bond is provided by the rapid hydrolysis of the pyrophosphate into two phosphate groups by an enzyme known as pyrophosphatase:

 

TLS Online TPP Program

#Id: 4989

#Unit 6. System Physiology – Plant

The greater proportion of far-red light converts more Pfr to Pr, and the ratio of Pfr to total phytochrome (Pfr/Ptotal) decreases.

TLS Online TPP Program

#Id: 4991

#Unit 6. System Physiology – Plant

When stimulated natural radiation was used to vary the far-red content, it was found that for so-called sun plants, the higher the far-red content (i.e., the lower the Pfr:Ptotal ratio), the higher the rate of stem extension.

TLS Online TPP Program

#Id: 4992

#Unit 6. System Physiology – Plant

For a “sun plant” or “shade-avoiding plant” there is a clear adaptive value in allocating its resources toward more rapid extension growth when it is shaded by another plant.

TLS Online TPP Program

#Id: 4993

#Unit 6. System Physiology – Plant

It can enhance its chances of growing above the canopy and acquiring a greater share of unfiltered, photosynthetically active light.

TLS Online TPP Program

#Id: 4994

#Unit 6. System Physiology – Plant

To favoring internode elongation is usually reduced leaf area and reduced branching, but at least in the short run this adaptation to canopy shade seems to work.

TLS Online TPP Program

#Id: 4997

#Unit 6. System Physiology – Plant

To favoring internode elongation is usually reduced leaf area and reduced branching, but at least in the short run this adaptation to canopy shade seems to work.