ABSTRACT
Being rooted in place, plants cannot evade attacks by pathogens and predators and they are permanently exposed to their physical environment, with changes in seasonal and diurnal cycles and extreme and stressful climatic variations. Among the abiotic factors, on which we will focus, a number of conditions are meaningful stresses because they can be life threatening and in combination determine plant distribution and the productivity of crop species (1). Prolonged drought, high or fluctuating salinity, and low and freezing temperatures account for most production losses, but flooding, high light, ozone, ion deficiency or imbalance, heavy metals, and soil structure are other factors that threaten plant life.
