Programmed chloroplast destruction during leaf senescence involves 13-lipoxygenase (13-LOX)

Mammals including humans use highly specific pathways for tissue differentiation. One such pathway is operative in reticulocytes and involves the programmed destruction of the cell?s organellar complement by 15-lipoxygenase (15-LOX), which oxygenates polyunsaturated membrane fatty acids and provokes organelle leakage. As we report here, plants make use of a similar LOX pathway to degrade their chloroplasts during leaf senescence. The enzyme involved is a 13-LOX with unique positional specificity and molecular terms. Because 15-LOX and 13-LOX pathway products likewise operate in biological defense, a mechanism of cross-kingdom conservation of pathway regulation and function was uncovered for multicellular eukaryotes