SAUR65 Antibody

Overview of SAUR65

SAUR65 is part of the SAUR gene family, which comprises growth regulators critical for differential organ development in response to light and auxin. In Arabidopsis, SAUR65 belongs to Class 3 of the lirSAURs (light-induced in cotyledons and/or repressed in hypocotyls SAURs), a subgroup whose expression correlates with organ-specific growth patterns during dark-to-light transitions .

Functional Role in Plant Growth

SAUR65 overexpression (e.g., 35S:SAUR65-GFP lines) significantly enhances cell expansion:

These phenotypes arise from SAUR65’s role in promoting cell wall acidification via H+-ATPase activation, which drives osmotic water uptake and cell expansion .

Molecular Mechanism

SAUR65 interacts with D-clade type 2C protein phosphatases (PP2C.Ds), inhibiting their activity to derepress plasma membrane H+-ATPases . Key mechanistic insights include:

SAUR65 competes with inhibitory SAURs (e.g., SAUR50) for PP2C-D binding, modulating growth asymmetry in apical hooks and cotyledons during photomorphogenesis .

Regulatory Dynamics

SAUR65 expression is tightly controlled by light and auxin:

• Light regulation: Repressed in hypocotyls but induced in cotyledons during dark-to-light transitions .

• Auxin sensitivity: Part of a broader SAUR network integrating hormonal and environmental signals .

Research Applications

While no commercial SAUR65 antibody is explicitly described in the literature, studies utilize transgenic approaches (e.g., GFP fusions) to track SAUR65 localization and function . Key findings include:

• SAUR65’s role in hypocotyl elongation under low light .

• Antagonistic interactions with other SAURs (e.g., SAUR17) to balance growth suppression and activation .

Open Questions

• Structural determinants of SAUR65-PP2C.D specificity.

• Cross-species functional conservation in crops .