Modification of root

Storage roots

Epiphytic or Aerial absorbing Roots e.g., Orchids.

Assimilatory roots

Respiratory roots or pneumatophores

Sucking roots or haustoria

Storage roots

Tap roots of carrot, radish, turnip and adventitious roots of sweet potato, dahlia get swollen and store food

TLS Online TPP Program

#Id: 9345

#XL - T Zoology

TGF-β activation

By cytoskeletal force transmitted by integrins

TLS Online TPP Program

#Id: 9346

#XL - T Zoology

The prodomains of TGF-β1 and TGF-β3 contain a RGD motif, that allows them to bind to integrins.

TLS Online TPP Program

#Id: 9347

#XL - T Zoology

During cell migration, a tensile force is generated which physically distorts the prodomain and frees the active TGF-β dimer, initiating TGF-β signaling.

TLS Online TPP Program

#Id: 9348

#XL - T Zoology

3 separate TGF-β receptor proteins participate in binding TGF-β and activating signaling:

RI, RII, and RIII

TLS Online TPP Program

#Id: 9350

#XL - T Zoology

RI and RII receptors are homodimeric proteins with serine/threonine kinases in their cytosolic domains. 

(RI and RII sufficient to serve as a functional hetero-tetrameric TGF-β receptor)

TLS Online TPP Program

#Id: 9351

#XL - T Zoology

RII exhibits constitutive kinase activity; means it is active even when not bound to TGF-β.