title: N-3-oxo-decanoyl-L-homoserine-lactone activates auxin-induced adventitious root formation via hydrogen peroxide- and nitric oxide-dependent cyclic GMP signaling in mung bean.
abstract: N-Acyl-homoserine-lactones (AHLs) are bacterial quorum-sensing signaling molecules that regulate population density. Recent evidence demonstrates their roles in plant defense responses and root development. Hydrogen peroxide (H(2)O(2)), nitric oxide (NO), and cyclic GMP (cGMP) are essential messengers that participate in various plant physiological processes, but how these messengers modulate the plant response to N-acyl-homoserine-lactone signals remains poorly understood. Here, we show that the N-3-oxo-decanoyl-homoserine-lactone (3-O-C10-HL), in contrast to its analog with an unsubstituted branch chain at the C3 position, efficiently stimulated the formation of adventitious roots and the expression of auxin-response genes in explants of mung bean (Vigna radiata) seedlings. This response was mimicked by the exogenous application of auxin, H(2)O(2), NO, or cGMP homologs but suppressed by treatment with scavengers or inhibitors of H(2)O(2), NO, or cGMP metabolism. The 3-O-C10-HL treatment enhanced auxin basipetal transport; this effect could be reversed by treatment with H(2)O(2) or NO scavengers but not by inhibitors of cGMP synthesis. Inhibiting 3-O-C10-HL-induced H(2)O(2) or NO accumulation impaired auxin- or 3-O-C10-HL-induced cGMP synthesis; however, blocking cGMP synthesis did not affect auxin- or 3-O-C10-HL-induced H(2)O(2) or NO generation. Additionally, cGMP partially rescued the inhibitory effect of H(2)O(2) or NO scavengers on 3-O-C10-HL-induced adventitious root development and auxin-response gene expression. These results suggest that 3-O-C10-HL, unlike its analog with an unmodified branch chain at the C3 position, can accelerate auxin-dependent adventitious root formation, possibly via H(2)O(2)- and NO-dependent cGMP signaling in mung bean seedlings.
authors.affiliation: Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, Institute of Tibet Plateau Research at Kunming, Chinese Academy of Sciences, Kunming 650204, China.
authors.forename: Xuegui
authors.initials: X
authors.lastname: Bai
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Todd
authors.forename: Radhika
authors.initials: R
authors.lastname: Desikan
authors.forename: Yongping
authors.initials: Y
authors.lastname: Yang
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Hu
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000502:physiology; D006152:Cyclic GMP / Q000378:metabolism*; D007887:Fabaceae / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism*; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000096:biosynthesis / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development*; D015398:Signal Transduction
chemical_list: D007210:Indoleacetic Acids; C088386:homoserine lactone; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D006152:Cyclic GMP; D015107:4-Butyrolactone