Stress Interruption of Potato Tuber Initiation: Production, Transport, Sensitivity, and the Cell Types Where It Happens

Tuber initiation is the window through which climate pressure reaches potato yield. The tuberigen SELF-PRUNING 6A (StSP6A) is leaf-derived and phloem-mobile. Reviews of stress are organised by stress type, not by the step at which interruption occurs. Competing routes are unweighted, and findings of different kinds sit at one level of confidence. We read that literature along four sites of the leaf-to-stolon axis: tuberigen production, long-distance transport, stolon responsiveness, and sugar-flux execution. Claims are graded by evidence kind and inference scope, with model-derived inference and cross-species analogy held apart. We read interruption as distributed along the axis, not convergent on one node; the four are unequally established. The stress biology of transport rests almost entirely on inference. Stress can lower the gain with which a stolon reads an arriving signal without changing its amount, which resolves the abscisic acid paradox on evidence from one group. A stress effect’s sign can depend on dose and developmental window, so single-stress results do not extrapolate. Production carries most evidence but acts against a feedback loop; responsiveness offers a second route, but neither is field-tested for yield. Discriminating experiments are needed. Which cell stress acts on remains open: no spatial transcriptome of the hooked stolon exists.