Exogenous supply of pantoyl lactone to excised leaves increases their pantothenate levels.
OBJECTIVE
All plants synthesize pantothenate but its synthesis and regulation are not well understood. The aim of this work is to study the effect of exogenous supply of precursor compounds on pantothenate levels in leaves.


METHODS
Precursor compounds were supplied in solution to excised leaves and the pantothenate content was measured using a microbial method.


RESULTS
Pantothenate levels in excised leaves of Limonium latifolium, tomato (Lycopersicon esculentum), bean (Phaseolus vulgaris) and grapefruit (Citrus x paradisi) were examined following an exogenous supply of the precursor compounds pantoyl lactone or beta-alanine. Significantly higher levels of extractable pantothenate were found when pantoyl lactone was supplied, but not when beta-alanine was supplied despite a measurable uptake of beta-alanine into the leaf.


CONCLUSIONS
The results suggested that the pantoate supply may be rate-limiting or regulating pantothenate synthesis in leaves.
Rathinasabapathi
Bala
B
Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA. brath@mail.ifas.ufl.edu
Raman
Suresh Babu
SB
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism*; D000409:Alanine / Q000378:metabolism; D007700:Kinetics; D018551:Solanum lycopersicum / Q000502:physiology; D010205:Pantothenic Acid / Q000378:metabolism*; D027805:Phaseolus / Q000502:physiology; D018515:Plant Leaves / Q000502:physiology*; D029606:Plumbaginaceae / Q000502:physiology; D014633:Valine / Q000378:metabolism
D010205:Pantothenic Acid; C005412:pantolactone; D014633:Valine; D000409:Alanine; D015107:4-Butyrolactone