Combined biotic and abiotic stress resistance in tomato

Abstract

Abiotic and biotic stress factors are the major constrains for the realization of crop yield potential. As climate change progresses, the spread and intensity of abiotic as well as biotic stressors is expected to increase, with increased probability of crops being exposed to both types of stress. Shielding crops from combinatorial stress requires a better understanding of the plant's response and its genetic architecture. In this study, we evaluated resistance to salt stress, powdery mildew and to both stresses combined in tomato, using the Solanum habrochaites LYC4 introgression line (IL) population. The IL population segregated for both salt stress tolerance and powdery mildew resistance. Using SNP array marker data, QTLs were identified for salt tolerance as well as Na ? and Cl -accumulation. Salt stress increased the susceptibility of the population to powdery mildew in an additive manner. Phenotypic variation for disease resistance was reduced under combined stress as indicated by the coefficient of variation. No correlation was found between disease resistance and Na ? and Cl -accumulation under combined stress Most genetic loci were specific for either salt stress tolerance or powdery mildew resistance. These findings increase our understanding of the genetic regulation of responses to abiotic and biotic stress combinations and can provide leads to more efficiently breeding tomatoes and other crops with a high level of disease resistance while maintaining their performance in combination with abiotic stress.

Responses to combined abiotic and biotic stress in tomato are governed by stress intensity and resistance mechanism

“…Moneymaker (MM) were selected on the basis of their salt tolerance and/or powdery mildew resistance (Kissoudis et al , 2015). Additionally, the NILs NIL-Ol-1, NIL-ol-2, and NIL-Ol-4 were used.…”

“…Fresh and dry weights were measured as described previously (Kissoudis et al , 2015). The disease severity was expressed as the disease index (DI) on a scale from 0 to 5, according to Kissoudis et al (2015), assessed at 10, 15, and 25 dpi for the first experiment and at 15 dpi for the second experiment.…”

Ethylene and Abscisic Acid Signaling Pathways Differentially Influence Tomato Resistance to Combined Powdery Mildew and Salt Stress

“…The concentration of Na + , Cl - , K + , PO 4 3- , SO 4 2- , Mg 2+ , and Ca 2+ was measured with ion chromatography as described previously (Kissoudis et al, 2015). …”

“…We previously demonstrated that PM resistance was negatively affected by 100 mM NaCl (EC level of 10 dS/m) in an introgression line population segregating for partial PM resistance (Kissoudis et al, 2015). Further research indicated that salt stress has the highest impact on disease susceptibility under mild stress conditions (EC∼6 dS/m, 50 mM NaCl), while more severe salinity restored resistance.…”

Tomato tolerance to abiotic stress: a review of most often engineered target sequences

“…Genes can be placed into various of expression cassettes, and subsequently introduced to plants in which they do not naturally occur. Genetically engineered plants can be employed not only as origin of novel cultivars, but can also be helpful in analysing and describing the activity and interplay of gene networks for abiotic stress tolerance (Kissoudis et al 2015). Given the complexity of stress and its genesis, it is rare to meet a single abiotic stress in nature.…”