Neighboring cells respond to cAMP in two ways:

Initiate a movement toward the cAMP pulse for about a minute

Release cAMP of their own

TLS Online TPP Program

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#Unit 6. System Physiology – Plant

DELLA is feedback regulator

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#Id: 10175

#Unit 6. System Physiology – Plant

In the absence of gibberellin, 

the DELLA proteins positively regulate GID1, GA20ox, and GA3ox, and negatively regulate GA2ox. 

TLS Online TPP Program

#Id: 10176

#Unit 6. System Physiology – Plant

Conversely bioactive gibberellin and the GID1 receptor enhance DELLA repressor degradation, while GA2ox blocks DELLA repressor degradation

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#Id: 10177

#Unit 6. System Physiology – Plant

DELLA degradation results in the release and activation of phytochrome interacting factor (PIF) transcription factors, such as PIF3 and PIF4, as well as other bHLH transcription factors

TLS Online TPP Program

#Id: 10178

#Unit 6. System Physiology – Plant

Binding of gibberellin receptor GID1 to DELLA repressor proteins triggers ubiquitination of the latter via the F-box protein SLY1 and subsequent degradation

TLS Online TPP Program

#Id: 10180

#Unit 6. System Physiology – Plant