Assessing the Involvement of Selected Phenotypes of Pseudomonas simiae PICF7 in Olive Root Colonization and Biological Control of Verticillium dahliae

Plants

Pilar Prieto¹  Nuria Montes-Osuna²  Antonio Valverde-Corredor²  CarmenGómez-LamaGómez-Lama Cabanás²  Jesús Mercado-Blanco²  RoelandL. Berendsen³ 

[1] Departamento de Mejora Genética Vegetal, Instituto de Agricultura Sostenible, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Avenida Menéndez Pidal s/n, Campus “Alameda del Obispo”, 14004 Córdoba, Spain;Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Avenida Menéndez Pidal s/n, Campus “Alameda del Obispo”, 14004 Córdoba, Spain;Plant–Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands;

关键词: biocontrol;    biofilm;    confocal laser scanning microscopy (CLSM);    copper tolerance;    defoliating (D) pathotype;    endophyte;   

DOI  :  10.3390/plants10020412

来源: DOAJ

【 摘 要 】

Pseudomonas simiae PICF7 is an indigenous inhabitant of the olive (Olea europaea L.) rhizosphere/root endosphere and an effective biocontrol agent against Verticillium wilt of olive (VWO), caused by the soil-borne fungus Verticillum dahliae. This study aimed to evaluate the potential involvement of selected phenotypes of strain PICF7 in root colonization ability and VWO biocontrol. Therefore, a random transposon-insertion mutant bank of P. simiae PICF7 was screened for the loss of phenotypes likely involved in rhizosphere/soil persistence (copper resistance), root colonization (biofilm formation) and plant growth promotion (phytase activity). Transposon insertions in genes putatively coding for the transcriptional regulator CusR or the chemotaxis protein CheV were found to affect copper resistance, whereas an insertion in fleQ gene putatively encoding a flagellar regulatory protein hampered the ability to form a biofilm. However, these mutants displayed the same antagonistic effect against V. dahliae as the parental strain. Remarkably, two mutants impaired in biofilm formation were never found inside olive roots, whereas their ability to colonize the root exterior and to control VWO remained unaffected. Endophytic colonization of olive roots was unaltered in mutants impaired in copper resistance and phytase production. Results demonstrated that the phenotypes studied were irrelevant for VWO biocontrol.

【 授权许可】

Unknown