Knock-out of SlDMR6-1 in tomato promotes a drought-avoidance strategy and increases tolerance to Late Blight

The DOWNY MILDEW RESISTANCE 6 (DMR6) protein is a 2-oxoglutarate (2OG) and Fe(II)-dependent oxygenase, involved in salicylic acid (SA) metabolism. SA is recognized as an abiotic stress-tolerance enhancer, and in tomato the inactivation of DMR6 was found increase its level and induce disease-resistance against several pathogens. By applying the CRISPR/Cas9 technique, we generated Sldmr6-1 tomato mutants and tested their tolerance to drought as well as to Late Blight. Wild-type tomato cultivar ‘San Marzano’ and its Sldmr6-1 mutants were subjected to water deprivation for 7 days. WT plants exhibited severe wilting, while T2 Sldmr6-1 mutants showed turgid leaves and maintained higher Soil Relative Water Content. Eco-physiological measurements highlighted that Sldmr6-1 mutants adopted a water saving behavior reducing transpiration rate by decreasing stomatal conductance. Under drought stress the assimilation rate decreased as well, resulting in no alteration of the CO2 concentration in the sub-stomatal chamber and increasing the Water Use Efficiency. Furthermore, in Sldmr6-1 mutants the drought stress induced up-regulation of the anti-oxidant related genes SlAPX and SlGST as well as down-regulation of SlCYP707A2 gene, which is involved in ABA catabolism. At last we highlighted, for the first time in tomato, that Sldmr6-1 mutants exhibited a reduced susceptibility to Phytophthora infestans, the causal agent of Late Blight.

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Bibliographic Details
Main Authors: Maioli, Alex, De Marchi, Federica, Valentino, Danila, Gianoglio, Silvia, Patono, Davide Lucien, Miloro, Fabio, Bai, Yuling, Comino, Cinzia, Lanteri, Sergio, Lovisolo, Claudio, Acquadro, Alberto, Moglia, Andrea
Format: Article/Letter to editor biblioteca
Language:English
Subjects:Downy mildew resistance 6, Drought stress, Gene editing, Solanum lycopersicum L., Susceptibility genes,
Online Access:https://research.wur.nl/en/publications/knock-out-of-sldmr6-1-in-tomato-promotes-a-drought-avoidance-stra
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