🇺🇸
/ˈɑːksɪn/
🇺🇸
/ˈɑːksɪn/
🇬🇧
/ˈɑːksɪn/
🇬🇧
/ˈɑːksɪn/
Plural
auxins
Auxin is a natural plant hormone that controls key growth processes like stem elongation, root formation, and directional responses to light and gravity — think of it as the plant's internal 'grow here, bend there' command system. For example, when sunlight hits one side of a seedling, auxin shifts to the shaded side, making those cells stretch faster and causing the shoot to bend toward the light.
Auxin produced in the shoot tip promotes cell elongation in young stems.
Farmers sometimes apply synthetic auxin to stimulate root growth in plant cuttings.
The asymmetric distribution of auxin drives phototropic bending in coleoptiles.
Disrupting auxin transport can lead to abnormal plant architecture and reduced fertility.
Researchers use fluorescent auxin reporters to visualize hormone movement in living Arabidopsis roots.
aux-
Comes from the Greek verb 'auxein' (αὐξεῖν), meaning 'to increase', 'to grow', or 'to enlarge'. This root conveys the core biological concept of growth promotion and cellular expansion. Examples include auxin, auxotroph, auxochrome, and auxesis.