title: Ethylene and Abscisic Acid Signaling Pathways Differentially Influence Tomato Resistance to Combined Powdery Mildew and Salt Stress.
abstract: There is currently limited knowledge on the role of hormones in plants responses to combinations of abiotic and pathogen stress factors. This study focused on the response of tomato near-isogenic lines (NILs) that carry theOl-1, ol-2, andOl-4loci, conferring resistance to tomato powdery mildew (PM) caused byOidium neolycopersici, to combined PM and salt stress. These NILs were crossed with thenotabilis(ABA-deficient),defenceless1(JA-deficient), andepinastic(ET overproducer) tomato mutants to investigate possible roles of hormone signaling in response to combined stresses. In the NILs, marker genes for hormonal pathways showed differential expression patterns upon PM infection. Theepinasticmutation resulted in breakdown of resistance in NIL-Ol-1 and NIL-ol-2. This was accompanied by reduced callose deposition, and was more pronounced under combined salt stress. Thenotabilismutation resulted in H2O2overproduction and reduced susceptibility to PM in NIL-Ol-1 under combined stress, but lead to higher plant growth reduction under salinity and combined stress. Resistance in NIL-ol-2 was compromised by thenotabilismutation, which was potentially caused by reduction of callose deposition. Under combined stress the compromised resistance in NIL-ol-2 was restored. PM resistance in NIL-Ol-4 remained robust across all mutant and treatment combinations. Hormone signaling is critical to the response to combined stress and PM, in terms of resistance and plant fitness. ABA appears to be at the crossroads of disease susceptibility/senescence and plant performance under combined stress These gained insights can aid in narrowing down targets for improving crop performance under stress combinations.
authors.affiliation: Plant Breeding, Wageningen University & Research Wageningen, Netherlands.
authors.forename: Christos
authors.initials: C
authors.lastname: Kissoudis
authors.affiliation: Biotechnology and Plant Breeding Department, Faculty of Agriculture, Ferdowsi University of Mashhad Mashhad, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Seifi
authors.affiliation: Plant Breeding, Wageningen University & Research Wageningen, Netherlands.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Yan
authors.affiliation: Plant Breeding, Wageningen University & Research Wageningen, Netherlands.
authors.forename: A T M Tanjimul
authors.initials: AT
authors.lastname: Islam
authors.affiliation: Plant Breeding, Wageningen University & Research Wageningen, Netherlands.
authors.forename: Hanneke
authors.initials: H
authors.lastname: van der Schoot
authors.affiliation: Plant Breeding, Wageningen University & Research Wageningen, Netherlands.
authors.forename: Clemens C M
authors.initials: CC
authors.lastname: van de Wiel
authors.affiliation: Plant Breeding, Wageningen University & Research Wageningen, Netherlands.
authors.forename: Richard G F
authors.initials: RG
authors.lastname: Visser
authors.affiliation: Plant Breeding, Wageningen University & Research Wageningen, Netherlands.
authors.forename: C G
authors.initials: CG
authors.lastname: van der Linden
authors.affiliation: Plant Breeding, Wageningen University & Research Wageningen, Netherlands.
authors.forename: Yuling
authors.initials: Y
authors.lastname: Bai
keywords: ROS burst; abscisic acid; callose; cell death; chitinase; senescence