Plant growth hormones, flowering, water relations

Plant growth hormones, flowering, water relations - Plant...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Plant Growth Regulators Some terms: - phototropism: studying plant movements - differential growth: one side of coleoptile is longer than the other side - malt: when seeds are converted from starch to sugar - alpha amylase: enzyme created by aleurone in a barley seed that converts starch to sugar - “reporter” or bioassay system: method of discovering new growth regulators that involves tissue culture & placing it in a growth medium - callus tissue: pith that is disorganized and not differentiated - dormin : materials produced in scales of dormant buds - vivipary: no dormancy for seed and attached to the mother plant 4 Plant Growth Regulators: 1 . A u x i n 2 . G i b e r e l l i n s / G i b e r e l l i c A c i d / G A 3 . C y t o k i n i n s 4 . E t h y l e n e 5 . A B A - A b s c i s i c A c i d Auxin : low molecular weight compound that has effects in very low concentrations 1. Apical Dominance: the main shoot apex inhibits lateral buds from growing out 2. Auxins are able to stimulate lateral reproduction (stimulate pericycle) 3. Stimulates division and differentiation in vascular cambium 4. Affects fruit development 5. “Leaf abscission” = leaf dropping 6. Photoperiod yields a reduction of auxin synthesis in the leaf Giberellins : product of rice fungus, but produced by all plants 1. Causes cell elongation 2. Stimulates Fowering 3. Used commercially to stimulate increase in size of tissues (i.e.: grapes) 4. Controls state of maturity (favors youth). - “juvenile condition”: no Fowers 5. Induces germination Bringing dormant seeds to germination using Giberellin: 1. Embryo releases GA 2. GA moves to aleurone layer Cytokinins : stimulate cytokinesis/ cell division 1. Stimulates cell division 2. Delays senescence: death/aging 3. In mixtures with other growth regulators, in tissue culture, we can cause the callus to differentiate - high concentration of auxin + low concentration of cytokinins = roots - moderate concentration of auxin + moderate concentration of cytokinins= undifferentiated - low concentration of auxin + high concentration of cytokinins= shoots
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
5. Causes tumors- increases cell division activity Ethylene : the most commercially important growth regulator - not transported through vascular system because it ʼ s a gas - triggers ripening in fruits - autocatalytic: can stimulate its own synthesis
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/09/2010 for the course BIO 1B taught by Professor Carlson,mischel,power during the Spring '07 term at Berkeley.

Page1 / 5

Plant growth hormones, flowering, water relations - Plant...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online