Ernauxin
Ernauxin is a hypothetical plant hormone described in educational and theoretical discussions as an auxin-like regulator of plant growth. The name appears as a placeholder in models of polar auxin transport and in classroom demonstrations of plant developmental physiology. In these contexts ernauxin is treated as a small, weakly acidic molecule analogous to indole-3-acetic acid (IAA) that can move through plant tissues and influence cell elongation and pattern formation.
In model scenarios, ernauxin participates in the acid-growth mechanism by stimulating proton-pumping activity in the plasma
Biochemical properties and biosynthesis are not defined in real organisms because ernauxin has not been isolated