Physiological and biochemical remarks on environmental stress in olive (Olea europaea L.)

Olive (Olea europaea L.) is an evergreen tree traditionally cultivated in the Mediterranean basin where plants undergo, to some degree, stress due to unfavourable environmental conditions. Water deficit, freezing, salinity and air pollution are a few of the stress factors restricting growth, so that olive productivity at the end of the growing season expresses only a fraction of the plant's genetic potential. Understanding the physiological and biochemical processes that enable olive adaptation and acclimation, as well as the mechanisms of stress injury, is therefore of relevant importance. However, the studies on the physiology and biochemistry of stress resistance and on the role of gene expression and protein synthesis in olive are almost in an initial phase when compared with the progress achieved for other cultivated plants. In this paper, the physiological and biochemical studies performed on olive plants exposed to the main environmental stresses will be analysed and discussed.