Rupali Gupta
Meirav Leibman-Markus
Gautam Anand
Dalia Rav David
Uri Yermiyahu
Yigal Elad
Maya Bar  

Nutrient elements play essential roles in plant growth, development and reproduction. Balanced nutrition is critical for plant health and the ability to withstand biotic stress. Treatment with essential elements has been shown to induce disease resistance in certain cases. Understanding the functional mechanisms underlying plant immune responses to nutritional elements has the potential to provide new insights into crop improvement. In the present study, we investigated the effect of different elements: Potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na), in promoting resistance against the necrotrophic fungus Botrytis cinerea (Bc) and the hemibiotrophic bacterium Xanthomonas euvesicatoria (Xcv) in tomato. We demonstrate that spray- treatment of essential elements was sufficient to activate immune responses, inducing defense gene expression, cellular leakage, reactive oxygen species, and ethylene production. We report that different defense signaling pathways are required for induction of immunity in response to different elements. Our results suggest that genetic mechanisms that are modulated by nutrient elements may be exploited in agricultural practices to promote disease resistance.