Inoculation of tomato plants (Solanum lycopersicum) with growth-promoting Bacillus subtilis retards whitefly Bemisia tabaci development.
Root inoculation of tomato (Solanum lycopersicum) plants with a Bacillus subtilis strain BEB-DN (BsDN) isolated from the rhizosphere of cultivated potato plants was able to promote growth and to generate an induced systemic resistance (ISR) response against virus-free Bemisia tabaci. Growth promotion was evident 3 weeks after inoculation. No changes in oviposition density, preference and nymphal number in the early stages of B. tabaci development were observed between BsDN-treated plants and control plants inoculated with a non-growth promoting Bs strain (PY-79), growth medium or water. However, a long-term ISR response was manifested by a significantly reduced number of B. tabaci pupae developing into adults in BsDN-treated plants. The observed resistance response appeared to be a combination of jasmonic acid (JA) dependent and JA-independent responses, since the BsDN-related retardation effect on B. tabaci development was still effective in the highly susceptible spr2 tomato mutants with an impaired capacity for JA biosynthesis. A screening of 244 genes, 169 of which were previously obtained from subtractive-suppressive-hybridization libraries generated from B. tabaci-infested plants suggested that the BsDN JA-dependent ISR depended on an anti-nutritive effect produced by the simultaneous expression of genes coding principally for proteases and proteinase inhibitors, whereas the JA-independent ISR observed in the spr2 background curiously involved the up-regulation of several photosynthetic genes, key components of the phenyl-propanoid and terpenoid biosynthetic pathways and of the Hsp90 chaperonin, which probably mediated pest resistance response(s), in addition to the down-regulation of pathogenesis and hypersensitive response genes.
Valenzuela-Soto
José Humberto
JH
Unidad de Biotecnología e Ingeniería Genética de Plantas, Cinvestav-Irapuato, Km 9.6 del Libramiento Norte Carretera Irapuato-León, Apartado Postal 629, C.P. 36821 Irapuato, Guanajuato, Mexico.
Estrada-Hernández
María Gloria
MG
Ibarra-Laclette
Enrique
E
Délano-Frier
John Paul
JP
D000818:Animals; D001412:Bacillus subtilis / Q000166:cytology / Q000502:physiology*; D016000:Cluster Analysis; D015169:Colony Count, Microbial; D018506:Gene Expression Regulation, Plant; D006430:Hemiptera / Q000254:growth & development*; D054884:Host-Pathogen Interactions; D018551:Solanum lycopersicum / Q000235:genetics / Q000254:growth & development / Q000382:microbiology* / Q000469:parasitology*; D009154:Mutation / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010940:Plant Proteins / Q000378:metabolism; D011157:Population Dynamics; D015203:Reproducibility of Results
D010940:Plant Proteins