Figure 5.

Floral abnormalities in rsw2-1 seen in plants transferred from 20°C to 31°C after bolting. A, Changes in the relative lengths of floral organs. Whole flowers (left) and petals and sepals removed (right). Columbia wild type (top); rsw2-1 complemented with KOR (middle); rsw2-1 (bottom). Petals, sepals, and stamen filaments are much shorter in the mutant than in wild type so that the receptive stigma protrudes beyond them in the mutant. All traits are corrected by transformation with KOR. B, The mixture of long and short cells characteristic of the wild-type sepal (left) is much less marked in sepals of rsw2-1 (right). Double-headed arrows show the long axis of the sepal. Asterisks show the slightly elongated cells in the mutant. C through F, Impaired anther dehiscence. The wild-type anther splits cleanly along the stomium before its surface cells visibly dessicate (C) and the anther wall folds right back as asymmetric shrinkage of the endothecial cells begins (D). rsw2-1 anthers, in contrast, fail to split along their stomium (arrow) even when shrinkage of epidermal cells has begun (E) but partial splitting may follow when epidermal cell shrinkage is extreme (F). Scale bars = 1 mm (A), 100 μm (B–E), 50 μm (F).