Stem cells are sometimes referred to as “undifferentiated” due to this maintenance of proliferative properties. ted cell type. 

TLS Online TPP Program

#Id: 9803

#Unit 6. System Physiology – Plant

The N-terminal a PAS domain 

a GAF domain with bilin-lyase activity, which binds the chromophore, 

PHY domain, which stabilizes phytochrome in the Pfr form

TLS Online TPP Program

#Id: 9804

#Unit 6. System Physiology – Plant

PAS-related domain (PRD) repeats mediate phytochrome dimerization. 

The PRD domain targets the Pfr form of phyB to the nucleus, although it lacks a canonical nuclear localization signal (NLS).

TLS Online TPP Program

#Id: 9805

#Unit 6. System Physiology – Plant

In higher plants the phytochrome chromophore is a linear tetrapyrrole called phytochromobilin

TLS Online TPP Program

#Id: 9806

#Unit 6. System Physiology – Plant

Pr chromophore undergoes a cis–trans isomerization between carbons 15 and 16 and rotation of the C14-C15 single bond on red light exposure.

TLS Online TPP Program

#Id: 9807

#Unit 6. System Physiology – Plant

Phytochromobilin is synthesized in plastids from chlorophyll biosynthetic pathway and transported into cytosol by a passive process.

TLS Online TPP Program

#Id: 9808

#Unit 6. System Physiology – Plant

Phytochromobilin is exported from the plastid to the cytosol where it autocatalytically attaches to the PHY apoprotein through a thioether linkage to a cysteine residue.