A clathrin molecule,

called a triskelion, is composed of : 

Three heavy chains

Three light chains

TLS Online TPP Program

#Id: 10167

#Unit 6. System Physiology – Plant

TLS Online TPP Program

#Id: 10168

#Unit 6. System Physiology – Plant

Compounds such as AMO-1618, Cycocel, and Phosphon D are specific inhibitors of the first stage of gibberellin biosynthesis, and they are used as growth height reducers

TLS Online TPP Program

#Id: 10169

#Unit 6. System Physiology – Plant

KNOXI gene and GA2 oxidase are primary regulators of GA

TLS Online TPP Program

#Id: 10170

#Unit 6. System Physiology – Plant

Auxin promotes the transcription of GA3ox and to repress the transcription of GA2ox

TLS Online TPP Program

#Id: 10171

#Unit 6. System Physiology – Plant

Gibberellins Enhance Cell Wall Extensibility without Acidification.

Enzyme Expansins and Xyloglucan endotransglycosylase (XET) is involved in gibberellin-promoted wall extension. The function of XET may be to facilitate the penetration of expansins into the cell wall.

TLS Online TPP Program

#Id: 10172

#Unit 6. System Physiology – Plant

Three main classes of mutations affecting plant height have

been selected:

1. Gibberellin-insensitive dwarfs

2. Gibberellin-deficient mutants in which the gibberellin deficiency has been overcome by a second “suppressor” mutation, so the plants look closer to normal

3. Mutants with a constitutive gibberellin response (“slender” mutants)