Growth promotion of Lactuca sativa in response to volatile organic compounds emitted from diverse bacterial species.
Agrochemicals are currently used in horticulture to increase crop production. Nevertheless, their indiscriminate use is a relevant issue for environmental and legal aspects. Alternative tools for reducing fertilizers and synthetic phytohormones are being investigated, such as the use of volatile organic compounds (VOCs) as growth inducers. Some soil bacteria, such as Pseudomonas and Bacillus, stimulate Arabidopsis and tobacco growth by releasing VOCs, but their effects on vegetables have not been investigated. Lactuca sativa was used as model vegetable to investigate bacterial VOCs as growth inducers. We selected 10 bacteria strains, belonging to Bacillus, Staphylococcus and Serratia genera that are able to produce 3-hydroxy-2-butanone (acetoin), a compound with proven growth promoting activity. Two-day old-seedlings of L. sativa were exposed to VOCs emitted by the selected bacteria grown in different media cultures for 7 days. The results showed that the VOCs released from the bacteria elicited an increase in the number of lateral roots, dry weight, root growth and shoot length, depending on the media used. Three Bacillus strains, BCT53, BCT9 and BCT4, were selected according to its their growth inducing capacity. The BCT9 strain elicited the greatest increases in dry weight and primary root length when L. sativa seedlings were subjected to a 10-day experiment. Finally, because acetoin only stimulated root growth, we suggest that other volatiles could be responsible for the growth promotion of L. sativa. In conclusion, our results strongly suggest that bacteria volatiles can be used as growth-inducers as alternative or complementary strategies for application in horticulture species.
Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile; Doctorado en Ciencias de Recursos Naturales, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile.
Paola
P
Fincheira
Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile.
Herbert
H
Venthur
Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile.
Ana
A
Mutis
Centro Biotecnológico de Estudios Microbianos (CEBEM), Departamento de Ciencias agronómicas, Universidad de La Frontera. Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile.
Maribel
M
Parada
Laboratorio de Química Ecológica, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco, Chile. Electronic address: andres.quiroz@ufrontera.cl.
Andrés
A
Quiroz
D000093:Acetoin / Q000378:metabolism*; D001407:Bacillus / Q000378:metabolism*; D018533:Biomass; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development* / Q000382:microbiology*; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development; D018520:Plant Shoots / Q000254:growth & development; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000382:microbiology; D012705:Serratia / Q000378:metabolism*; D013210:Staphylococcus / Q000378:metabolism*; D055549:Volatile Organic Compounds / Q000378:metabolism*
D010937:Plant Growth Regulators; D055549:Volatile Organic Compounds; D000093:Acetoin
3-Hydroxy-2-butanone; Lactuca sativa; Soil bacteria; Volatile organic compounds