Supplementary data: Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and mechanism of resistance

作者：Christos Kissoudis, Sri Sunarti, van de C.C.M. Wiel, Richard G. F. Visser, van der C.G. Linden, Yuling Bai · 发表于：Socio-Environmental Systems Modeling · 年份：2016 · DOI：10.18174/369637 · 研究领域：Plant Pathogens and Resistance、Flowering Plant Growth and Cultivation、Plant Stress Responses and Tolerance

Stress conditions in agricultural ecosystems can occur in variable intensities. Different resistance mechanisms to abiotic stress and pathogens are deployed by plants. Thus, it is important to examine plant responses to stress combinations under different scenarios. Here, we evaluated the effect of different levels of salt stress ranging from mild to severe (50, 100 and 150mM NaCl) on powdery mildew (PM) resistance and overall performance of tomato introgression lines with contrasting levels of partial resistance, as well as isogenic lines carrying the PM resistance genes Ol-1 (associated with slow Hypersensitivity Response; HR), ol-2 (a mlo mutant associated with papilla formation) and Ol-4 (a R gene associated with fast HR). PM resistance was affected by salt stress in a genotype and stress intensity dependent manner. In susceptible and partial resistant lines, increased susceptibility was observed under mild salt stress (50mM) which was accompanied with accelerated cell death-like senescence. On the contrary, severe salt stress (150mM) reduced disease symptoms. Na+ and Cl- accumulation in the leaves was linearly related to the decreased pathogen growth under severe stress, suggesting a more direct role for the salt in suppressing PM growth. In contrast, complete resistance mediated by ol-2 and Ol-4 was unaffected under all treatment combinations, and was associated with a decreased growth penalty. Increased susceptibility and senescence under combined stress of the variety...