Strigolactones regulate sepal senescence in Arabidopsis

Abstract Flower sepals are critical for flower development and vary greatly in life span depending on their function post-pollination. Very little is known about what controls sepal longevity. Using a senescence mutant screen, we identified two Arabidopsis mutants with delayed directly connecting strigolactones regulation novel floral context that hitherto has not been explored. The mutations were the strigolactone biosynthetic gene MORE AXILLARY GROWTH1 (MAX1) receptor DWARF14 (AtD14). mutation AtD14 changed catalytic Ser97 to Phe enzyme active site, which first of its kind planta. lesion MAX1 was haem–iron ligand signature cytochrome P450 protein, converting highly conserved Gly469 Arg, shown transient expression assay substantially inhibit activity MAX1. highlighted importance driving completion initiated both developmentally response carbon-limiting stress, as found more well-known senescence-associated regulators ethylene abscisic acid. Analysis transcript abundance excised inflorescences during an extended night suggested intricate relationship among sugar starvation, senescence, biosynthesis signalling.