The role of @entity8037 (SM) was studied to verify if SM supplied to @entity286 flower can modulate @entity204 ( @entity204 ) of the corolla. SM has strong effects on the development and senescence of excised flowers despite its low physiological levels. The timing and duration of SM treatment is a key factor; SM counteracts @entity204 (verified by morphological observations, pigment contents and DNA laddering) only in the narrow developmental window of corolla expansion. Before and after, SM promotes @entity204 . SM exerts its pro-survival role by delaying fresh @entity353 , by inhibiting reduction of pigments and finally by preventing DNA degradation. Moreover, SM deeply alters the distribution of the PA-conjugating enzyme transglutaminase (TGase). TGase is present in the epidermis during development, but it sprays also in the cell walls of inner parenchyma at senescence. After SM treatment, parenchyma cells accumulate TGase, increase in size and their cell walls do not undergo stiffening contrarily to control cells. The subcellular localization of TGase has been validated by biolistic-transformation of onion epidermal cells. Results indicated that SM is a critical factor in the senescence of @entity286 corolla by controlling biochemical and morphological parameters; the lasts are probably interconnected with the action of TGase.

XXXX either delays or promotes cell death in @entity286 . corolla depending on the floral developmental stage and affects the distribution of transglutaminase.

@entity286 :: ('4097', 'Species') :: ['N. tabacum', 'Nicotiana tabacum'] @entity204 :: ('MESH:D003643', 'Disease') :: ['PCD', 'programmed cell death'] @entity8037 :: ('MESH:D013096', 'Chemical') :: ['spermine'] @entity353 :: ('MESH:D015431', 'Disease') :: ['weight loss']
@entity8037 :: (MESH:D013096,Chemical) :: ['Spermine']
