Induction of potato systemic resistance against the potato virus Y (PVYNTN), using crude filtrates of Streptomyces spp. under greenhouse conditions

Egyptian Journal of Biological Pest Control

Table 1 Expression of PR1-b gene in different potato cultivars after application of different SCF under greenhouse conditions.

Treatment	Spunta (CT value)				Nicola (CT value)				Selatar (CT value)				Diamant (CT value)
Treatment	PR1	Cox	ΔΔCT	RQ	PR1	Cox	ΔΔCT	RQ	PR1	Cox	ΔΔCT	RQ	PR1	Cox	ΔΔCT	RQ
SCF7	Und.	20.0	Und.	Und.	16.5	20.2	− 3.7	12.9	18.0	22.0	− 4.0	16.0	Und.	19.9	Und.	Und.
SCF11	17.7	20.0	− 2.3	4.9	16.3	23.1	− 6.8	11.4	17.4	21.4	− 4.0	16.0	23.2	23.6	− 0.4	1.3
SCF20	18.0	20.0	− 2.0	4.0	19.1	22.0	− 2.9	7.4	Und.	21.8	Und.	Und.	20.0	21.4	− 1.4	2.6
Healthy (Non-PVY infected)	Und.	20.0	Und.	Und.	Und.	22.0	Und.	Und.	Und.	20.9	Und.	Und.	Und.	20.7	Und.	Und.
PVY Infected	Und.	21.0	Und.	Und.	Und.	19.6	Und.	Und.	Und.	22.0	Und.	Und.	Und.	22.0	Und.	Und.

Represent the expression level of PR1-b gene as detected at two time intervals; 7 days after virus inoculation (DAVI) (not expressed) and 21 DAVI (current table)
The foliar spraying of potato cultivars using different Streptomyces crude filtrates at 7 DBVI and also 7 DAVI
Represent culture filtrates of Streptomyces netropsis DSM 40093 (SCF7), Streptomyces ambofaciens (SCF11), and Streptomyces actuosus (SCF20)
CT value is the PCR cycle number at which the curve intersects the threshold (horizontal line), where fluorescence meets the threshold in the amplification plot. Undetected was considered negative result, cycle threshold Ct > 30 considered negative while, Ct < 30 considered positive result. PR1: gene encoding for pathogenesis related protein. Cox: encoding for cytochrome oxidase of potato (reference gene). Und: undetected. Data were collected from the mean values of Ct of two replicated run by real time PCR and the whole experiment was conducted twice.