A primordium-level ice barrier in Vaccinium corymbosum floral buds is lost as their xylem trace matures

Primordia of Vaccinium corymbosum floral buds maintain an ice-free barrier in fall and winter, but it is lost in spring as the xylem trace matures.

• Why it matters: The study addresses where the unexplained biological ice barrier is located and whether maturation of the lignified connection, rather than its presence, tracks seasonal loss.
• What they did: Buds from fall, winter, and spring were tested with structure-resolved freezing assays plus thermal analysis and cryomicroscopy, alongside xylem anatomy and measurements of water content and LT50.
• The result: Whole-bud LT50 shifted from -20 C (fall) to -31 C (winter) to -16 C (spring), with ice nucleating in the stem and reaching primordia; the primordium-level barrier disappeared as xylem elements changed and junction conduits stayed 2 to 3 um.

AI summary of the abstract · may contain errors · not medical advice · read the paper.