Blossom-end rot in fruit vegetables

Calcium (Ca) is an essential element for plant growth, as calcium deficiency causes various disorders in some types of horticultural crops. The most significant calcium deficiency disorder is blossom-end rot (BER) of fruit vegetables. In tomato (Solanum lycopersicum), one of the most important vegetables in the world, the incidence of BER often becomes a serious problem in agricultural production and results in financial losses. The typical external symptoms of BER in tomato are water-soaked tissues, necrosis, and discoloring of tissues in the distal portion of the fruit. BER develops in the necrotic region of the parenchymal tissue surrounding young seeds and the distal placenta in the internal tissue of the fruit. The symptoms and causes of BER have been extensively studied, and BER is assumed to be related to Ca deficiency of the fruit. Here, we reviewed symptoms and physiological mechanisms of BER that are related to Ca concentration in fruit tissue and focus on recent molecular genetic research on tomato BER.