+TIPs, associate with growing plus ends and can link microtubules to other structures, such as membranes.

TLS Online TPP Program

#Id: 9868

#Unit 6. System Physiology – Plant

The photoreceptor for UV-B-induced responses is UVR8, is a seven-bladed b-propeller protein, which forms functionally inactive homodimers in the absence of UV-B

TLS Online TPP Program

#Id: 9869

#Unit 6. System Physiology – Plant

UVR8 lacks a prosthetic chromophore

TLS Online TPP Program

#Id: 9870

#Unit 6. System Physiology – Plant

Upon absorbing UV-B photons, the tryptophans undergo structural changes that break the salt bridges, leading to the dissociation of the two functionally active monomers. The monomers then interact with COP1–SPA complexes to activate gene expression

TLS Online TPP Program

#Id: 9871

#Unit 6. System Physiology – Plant

The UVR8- COP1-SPA complex then activates the transcription of the major transcription factor HY5, which controls the expression of many of the genes induced by UV-B.

TLS Online TPP Program

#Id: 9721

#Unit 6. System Physiology – Plant

Plant immunity involves

Anatomical/Mechanical Barriers & Constitutive Immunity

Inducible Défense

TLS Online TPP Program

#Id: 9722

#Unit 6. System Physiology – Plant

Thorns are modified branches, as in citrus and acacia; spines

are modified leaves

Prickles are derived mainly from the epidermis and thus can be easily snapped off the stem, protect plants from larger herbivores

Trichomes, or hairs, provide a much more effective defense against insect pests