Small heat shock protein required for the establishment of auxin gradients and for patterning of the apical domain of the embryo. Involved in the specification of the cotyledon primordia. Also required for normal inflorescence and floral meristem function, normal developmental patterning and thermotolerance. Acts as a molecular chaperone. cytoplasmic at basal temperatures, but forms heat shock granules containing canonical small heat shock proteins at high temperatures. Expressed in all seedling tissues with highest expression levels at the root tip. Expressed during early embryo development, from the eight-cell stage until the end of the heart stage. Up-regulated by heat shock. Embryo lethal.