The induction of systemic defence responses in zucchini leaves treated by a water extract of Anabaena sp. BEA0300B strain was studied firstly through a bioassay under Podosphaera xanthii (Castagne) U. Braun and Shishkoff challenge. In a second experiment, enzyme activities correlated to induced systemic resistance were assayed 1, 2 and 3 days after treatment (DAT) with BEA0300B on untreated cotyledonar leaves. Endochitinase, b-N-acetylhexosaminidase, chitin 1,4-b-chitobiosidase, b-1,3-glucanase and peroxidases were spectrophotometrically determined. Enzyme isoforms were detected after isoelectric focusing. The extract reduced P. xanthii symptoms by 25%, similarly to chitosan, the positive control. BEA0300B treatment caused systemic accumulation of all the enzymes. In particular, the treatment provoked an early increase of total chitinase activity (15–38%) and of the expression of two constitutive chitinase isoforms, pI 4.4 (159%) and pI 4.6 (433%). The total b-1,3-glucanase and peroxidase activities were transiently increased. The expression of two constitutive isoforms of these enzyme increased, particularly pI 5.0 glucanase (148%, 1 DAT) and pI 4.9 peroxidase (181%, 2 DAT). BEA0300B water extract also showed a direct antifungal activity on pathogen sporulation.
Induction of defence responses in zucchini (Cucurbita pepo) by Anabaena sp. water extract / Roberti R.; Galletti S.; Burzi P.L .; Righini H.; Cetrullo S.; Perez C.. - In: BIOLOGICAL CONTROL. - ISSN 1049-9644. - ELETTRONICO. - 82:(2015), pp. 61-68. [10.1016/j.biocontrol.2014.12.006]
Induction of defence responses in zucchini (Cucurbita pepo) by Anabaena sp. water extract
ROBERTI, ROBERTA;RIGHINI, HILLARY;CETRULLO, SILVIA;
2015
Abstract
The induction of systemic defence responses in zucchini leaves treated by a water extract of Anabaena sp. BEA0300B strain was studied firstly through a bioassay under Podosphaera xanthii (Castagne) U. Braun and Shishkoff challenge. In a second experiment, enzyme activities correlated to induced systemic resistance were assayed 1, 2 and 3 days after treatment (DAT) with BEA0300B on untreated cotyledonar leaves. Endochitinase, b-N-acetylhexosaminidase, chitin 1,4-b-chitobiosidase, b-1,3-glucanase and peroxidases were spectrophotometrically determined. Enzyme isoforms were detected after isoelectric focusing. The extract reduced P. xanthii symptoms by 25%, similarly to chitosan, the positive control. BEA0300B treatment caused systemic accumulation of all the enzymes. In particular, the treatment provoked an early increase of total chitinase activity (15–38%) and of the expression of two constitutive chitinase isoforms, pI 4.4 (159%) and pI 4.6 (433%). The total b-1,3-glucanase and peroxidase activities were transiently increased. The expression of two constitutive isoforms of these enzyme increased, particularly pI 5.0 glucanase (148%, 1 DAT) and pI 4.9 peroxidase (181%, 2 DAT). BEA0300B water extract also showed a direct antifungal activity on pathogen sporulation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
