By 2050, the world population is expected to reach 9.6 billion, and to meet the rising demands arising out of this, estimates of the Food and Agriculture Organization project that global food production has to increase by 60% (fao.org). On top of the rising demand for food, there are several reasons to be concerned about insufficient global food production in the future (Rosegrant and Cline, 2003; Schmidhuber and Tubiello, 2007; Brown and Funk, 2008). For instance, climatic prediction models indicate severe weather pattern changes, which will result in more frequent droughts and floods, rising global temperature and decreased availability of freshwater for agriculture. Moreover, arable land is shrinking because of soil erosion, salinity and other soil toxicities (Stocking, 2003). Finally, it is expected that global climate changes will result in the emergence of new pest and diseases into production areas previously not affected. As a result of this situation, crops will have to thrive in a dynamic environment constantly challenged by changing abiotic and biotic stresses that currently cause an estimated yield loss of up to 60% (Seo et al., 2011). Therefore, in addition to dedicating efforts to conserve water and land resources, the current challenge in agriculture is to increase crop productivity by improving crop resistance and tolerance to pests, diseases and environmental stresses, respectively.