Cause tropism向性运动 LA) Vertcal dentate dele stators Light Gravitropism phototropism Relocation of auxin cause differential growth
Gravitropism phototropism Relocation of auxin cause differential growth Cause tropism 向性运动
Mechanism of auxin action Auxin binds to plasma Activated proto cell wall plasma membrane ATP H auxin-o o Auxin mode of action in binds to a receptor, the combination stimulates the proton pump so that hydrogen ions(H") are transported out of the cell. The acidity causes the cell wall to weaken, and the electrochemical gradient causes solutes to enter the cell. Water follows by osmosis
Mechanism of auxin action
Mechanism of auxin action auxin Hormone receptor Signal transduction Biosynthesis of nucleic Stimulate h Activate acid and protein ATPase gene H-ATPase expression New material for enlarged Synthesis more cell wall and cytoplasm H-ATPase Cell wall acidification Cell wall weakening Cell elongation
Mechanism of auxin action Hormone receptor Signal transduction Cell wall acidification Biosynthesis of nucleic acid and protein Activate H+ -ATPase Stimulate H+ - ATPase gene expression Synthesis more H+ -ATPase Cell wall weakening Cell elongation New material for enlarged cell wall and cytoplasm Auxin
Gibberellin history 9 Japanese scientists in the early 20th century frequently observed bakanae disease in rice o Disease caused by a fungus secreting a chemical that stimulates stem growth Q Additional study of fungal and plant GAs revealed a large group of compounds
Gibberellin history
GA family and its structure ACTIVE GIBBERELLINS General structure ofga (E)Gibberellin A,(GA1) (F)Gibberellic acid (GA3) There are >100 different gas There are few bioactive GAs(Gal, GA3) Others are intermediates or inactivated Free gibberellin -bound gibberellin Active nactive
GA family and its structure There are >100 different GAs There are few bioactive GAs (GA1, GA3) Others are intermediates or inactivated General structure of GA Free gibberellin ------------bound gibberellin Active inactive