Klebsiella michiganensis Kd70 promotes growth in plants by direct and indirect mechanisms

DANTUR K.I.; CASTAGNARO, A.P.; FILIPPONE P.; WELIN, BJÖRN; CLAPS M.P.; GONZÁLEZ V.; CHALFOUN N.R.

Córdoba

Congreso; XXXII Reunión Argentina de Fisiología Vegetal y XVI Congreso Latinoamericano de Fisiologíua Vegetal; 2018

Sociedad Argentina de Fisiología Vegetal

Plant growth-promoting bacteria (PGPB) can enhance plant growth by direct or indirect mechanisms including release of volatile compounds (VCs). In this study we evaluated the ability of a plant endophytic bacterium, K. michiganensis Kd70, to colonize and promote growth of sugarcane plantlets and in vitro-grown Arabidopsis by production of VCs. For sugarcane experiments the rhizosphere of 2-weeks-old sugarcane plantlets were inoculated with a Kd70 suspension and biomass development was compared to plants treated with water or a commercial bio-fertilizer product. In experiments with Arabidopsis, disinfected seeds sown on MS agar plates were exposed to agar plugs attached to the Petri dish lid, containing Kd70 bacteria and measurements of primary root length, number and length of secondary roots were made after 10 days of growth.Our results show that Kd70 enhance growth of both plant species resulting in a significant increase in fresh and dry weight of aerial parts and on fresh weight of the radicular system of sugarcane plantlets. In addition, seedlings of Arabidopsis exposed to bacterial VCs showed longer primary roots, greater number of secondary roots and foliar development than non-treated control plants. These findings indicate that bacterial strain Kd70 stimulates plant growth by both direct and indirect mechanisms.