BI111 Lecture Notes - Lecture 19: Circadian Rhythm, Phytochrome, Pulvinus
Document Summary
Isolates an infection site by surrounding it with dead cells. Salicylic acid (sa) induces synthesis of pr (pathogenesis-related) proteins. Secondary metabolites: defend against pathogens and herbivores, plants counter bacteria and fungi by making phytoalexins, function as antibiotics, other examples of secondary metabolites, caffeine, cocaine, strychnine, tannins, terpenes: conifer resins, essential oils. Gene-for-gene recognition: enables plat to recognize pathogen chemically and mount defenses against it, matchup between products of dominant alleles of two types of genes, plant"s r gene, pathogen"s avr gene. Plant responses to the environment: movements: phototropisms are responses to light, gravitropism orients plant parts ot the pull of gravity, thigmotropism and thigmomorphogenesis are responses to physical contact, nastic movements are nondirectional. Phtootropisms: growth responses to directional light source, blue light receptors trigger auxin transport, auxin triggers differential cell elongation. Gravitropism: growth response to earth"s gravitational pull, statolights (modified plasmids) move in response to gravity.
