BIOL 1108 Chapter Notes - Chapter 32: Systemic Acquired Resistance, Plant Cell, Heterotroph
Review
Plants are autotrophs
⇒ entry point of energy into ecosystems
⇒ where is the energy? in the plant body
⇒ target for heterotrophs through predation/parasitism
Threat => defense
- Internal: physiological, chemical
- External:
- first line of defense: cuticle, hairs, spines, …
- growth (think of grasses)
- biotic: recruiting ally such as ants.
Threat => recognition => defense <= all this implies costs and hence trade-offs.
Same process in predator => arms race.
Core Concepts
• Plants have evolved mechanisms to protect themselves
from infection by pathogens, which include viruses,
bacteria, fungi, worms, and even parasitic plants.
• Plants use chemical, mechanical, and ecological defenses
to protect themselves from being eaten by herbivores.
• The production of defenses is costly, resulting in tradeoffs
between protection and growth.
•Interactions among plants, pathogens, and herbivores
contribute to the origin and maintenance of plant
Diversity.
Types of parasites
7
Parasites feed on living (biotropic) or dead (necrotropic)
cells.
Some rely on the living cells to reproduce (use the cells
machinery to replicate DNA).
Parasitic plants, tap into the host plant’s tissue to retrieve
water and minerals or sugars.
Can plants acquire a defense, that
is acquire immunity?
The experiment with tobacco
infected with TMV led to the
concept of “systemic acquired
resistance”.
Signal must have been transmitted
- triggering a response in the still
Document Summary
Where is the energy? in the plant body. First line of defense: cuticle, hairs, spines, . Threat => recognition => defense <= all this implies costs and hence trade-offs. Parasites feed on living (biotropic) or dead (necrotropic) cells. Some rely on the living cells to reproduce (use the cells machinery to replicate dna). Parasitic plants, tap into the host plant"s tissue to retrieve water and minerals or sugars. The experiment with tobacco infected with tmv led to the concept of systemic acquired resistance . Triggering a response in the still healthy tissues. Some bacteria acquired the ability to insert some of its genome into the plant"s own genome and triggering a behavior by the plant cell. It infects roots and stems and causes galls, by the proliferation of plant cells (triggered by hormones and synthesized by the infected plant cells).
