title: Plant growth inhibitors isolated from sugarcane (Saccharum officinarum) straw.
abstract: Several compounds related with plant defense and pharmacological activities have been isolated from sugarcane. Straw phytotoxins and their possible mechanisms of growth inhibition are largely unknown. A bioassay-guided fractionation of the phytotoxic constituents leachated from a sugarcane straw led to the isolation of trans-ferulic (trans-FA), cis-ferulic (cis-FA), vanillic (VA) and syringic (SA) acids. The straw leachates and their identified constituents significantly inhibited root growth of lettuce and four weeds. VA was more phytotoxic to root elongation than FA and SA. The identified phenolic compounds significantly increased leakage of root cell constituents, inhibited dehydrogenase activity and reduced chlorophyll content in lettuce. VA and FA inhibited mitotic index while SA increased cell division. Additive (VA-FA and FA-SA) and synergistic (VA-SA) interactions on root growth were observed at the response level of EC(25). Although the isolated compounds differed in their relative phytotoxic activities, the observed physiological responses suggest that they have a common mode of action. HPLC analysis indicated that sugarcane straw can potentially release 1.43 (ratio 2:1, trans:cis), 1.14 and 0.14mmolkg(-1) (straw dry weight) of FA, VA and SA, respectively. As phenolic acids are often found spatially concentrated in the top soil layers under plant straws, further studies are needed to establish the impact of these compounds in natural settings.
authors.affiliation: Cátedra de Fitoquímica, Instituto de Estudios Vegetales Dr. A. R. Sampietro, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471 (4000), San Miguel de Tucumán, Argentina. sampietro@tucbbs.com.ar
authors.forename: Diego Alejandro
authors.initials: DA
authors.lastname: Sampietro
authors.forename: Marta Amelia
authors.initials: MA
authors.lastname: Vattuone
authors.forename: María Ines
authors.initials: MI
authors.lastname: Isla
mesh_terms: D000146:Acids, Carbocyclic / Q000302:isolation & purification / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000302:isolation & purification / Q000494:pharmacology; D007536:Isomerism; D063245:Plant Development; D010937:Plant Growth Regulators / Q000302:isolation & purification / Q000494:pharmacology*; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000254:growth & development; D010944:Plants / Q000187:drug effects; D031786:Saccharum / Q000737:chemistry*; D014641:Vanillic Acid / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000146:Acids, Carbocyclic; D003373:Coumaric Acids; D010937:Plant Growth Regulators; D005707:Gallic Acid; C004999:ferulic acid; C001945:syringic acid; D014641:Vanillic Acid