Mechanisms of resistance to powdery mildew in cucumber


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Tek M. İ. , Çalış Ö.

PHYTOPATHOLOGIA MEDITERRANEA, vol.61, no.1, pp.119-127, 2022 (Journal Indexed in SCI)

  • Publication Type: Article / Article
  • Volume: 61 Issue: 1
  • Publication Date: 2022
  • Doi Number: 10.36253/phyto-13313
  • Title of Journal : PHYTOPATHOLOGIA MEDITERRANEA
  • Page Numbers: pp.119-127

Abstract

Podosphaera xanthii
causes powdery mildew of cucumber, and is associated
with significant yield and quality losses. Development of resistant or tolerant varieties
is the most effective and eco-friendly strategy for powdery mildew management. An
important host resistance mechanism is based on the recognition of conserved resistance
genes, resulting in durable resistance. To determine powdery mildew resistance mecha-
nisms in cucumber, total RNAs were isolated from the powdery mildew resistant culti-
var Meltem, the tolerant line VT18, and the susceptible local variety Camlica. Expression
levels of nine genes in these plants were analysed by Reverse Transcription Polymerase
Chain Reaction (RT-PCR). The host reactions were assessed using microscope observa-
tions of stained specimens.
Serine/threonine
(
STN7)
,
transcription
factor
(
WRKY22)
,
ser
-
ine/threonine-protein kinase
(
D6PKL1
), and
serine/threonine receptor kinase
(
NFP
) genes
were induced, as positive regulators in defence mechanisms against powdery mildew.
Polygalacturonase Inhibitor (PGIP
) did not express after
P. x a n t h i i
inoculation of Camlica,
resulting in susceptibility. After inoculation,
callose synthase (CALLOSE)
and
cinnamyl
alcohol dehydrogenase
(
CAD
) gene expression levels were increased in resistant Meltem,
but Hypersensitive Reaction (HR) and ROS formation were only linked in the tolerant
VT18. Powdery mildew development was less in Meltem than in VT18, indicating that
cell wall thickening and HR play separate roles in resistance to this diseasePodosphaera xanthii
causes powdery mildew of cucumber, and is associated
with significant yield and quality losses. Development of resistant or tolerant varieties
is the most effective and eco-friendly strategy for powdery mildew management. An
important host resistance mechanism is based on the recognition of conserved resistance
genes, resulting in durable resistance. To determine powdery mildew resistance mecha-
nisms in cucumber, total RNAs were isolated from the powdery mildew resistant culti-
var Meltem, the tolerant line VT18, and the susceptible local variety Camlica. Expression
levels of nine genes in these plants were analysed by Reverse Transcription Polymerase
Chain Reaction (RT-PCR). The host reactions were assessed using microscope observa-
tions of stained specimens.
Serine/threonine
(
STN7)
,
transcription
factor
(
WRKY22)
,
ser
-
ine/threonine-protein kinase
(
D6PKL1
), and
serine/threonine receptor kinase
(
NFP
) genes
were induced, as positive regulators in defence mechanisms against powdery mildew.
Polygalacturonase Inhibitor (PGIP
) did not express after
P. x a n t h i i
inoculation of Camlica,
resulting in susceptibility. After inoculation,
callose synthase (CALLOSE)
and
cinnamyl
alcohol dehydrogenase
(
CAD
) gene expression levels were increased in resistant Meltem,
but Hypersensitive Reaction (HR) and ROS formation were only linked in the tolerant
VT18. Powdery mildew development was less in Meltem than in VT18, indicating that
cell wall thickening and HR play separate roles in resistance to this disease