BI111 Lecture Notes - Lecture 10: Brassica Oleracea, Meristem, Gibberellin

36 views10 pages
9 Feb 2017
School
Department
Course
Professor
Brassica oleracea- Seed Cabbage
Cultivars-not different species but different breeding groups-derived from ancestors
Vegetables are cultivars of Brassica oleracea
Each one represents a change in selection in parts of the brassica oleracea
Plant Growth and Development
To understand diversity of plant structures and life histories, need to understand role that signal
response pathways play in their growth and development
Signal Response Pathways
Hormones and environment stimuli alter behaviour of target cells
o Signal molecules bind to receptors in target cells
o Elicit cellular response (different response in different tissue)
By means of a response pathway, signal can:
o Induce changes in cells shape or internal structure
o Influence cells metabolism
o Alter gene activation and rate of protein synthesis
o Set in motion events that modify existing cell proteins
Some hormones and growth factors bind to receptors at target cells plasma membrane, on ER, or
in cytoplasm
Binding triggers release of internal second messengers that diffuse through cytoplasm and
provide main chemical signal that alters cell functioning
Reaction sequence amplifies cells response to signal
Plant Hormones: 7 Major Classes
Auxins promote growth
Gibberellins stimulate growth, including the elongation of stems
Cytokinins enhance growth and retard aging
Ethylene regulates a range of responses, including senescence
Brassinosteroids regulate plant growth responses
Abscisic acid suppresses growth and influences responses to environmental stress
Jasmonates and oligosaccharins regulate growth and have roles in plant defense
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 10 pages and 3 million more documents.

Already have an account? Log in
Auxins
Mainly indoleacetic acid (IAA)
Synthesized primarily in shoot apical meristem and young stems and leaves(new young growing
tissues)
Promotes elongation of cells
Governs growth responses to light and gravity
Apical meristem-produced in the tip of the stem
Important in response of plant growth and response to gravity
Gravitropism
Positive toward the direction of gravity as with roots
Negative away from the direction of gravity as with shoots
Phototropism: Growth in response to light
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 10 pages and 3 million more documents.

Already have an account? Log in
Light guided development of the plant is called photo morphogenesis
Cell Expansion: Acid-Growth Hypothesis
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 10 pages and 3 million more documents.

Already have an account? Log in

Get OneClass Notes+

Unlimited access to class notes and textbook notes.

YearlyBest Value
75% OFF
$8 USD/m
Monthly
$30 USD/m
You will be charged $96 USD upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.