PROGRAMMED CELL DEATH AND POSTHARVEST DETERIORATION OF HORTICULTURAL PRODUCE

Abstract

Programmed cell death (PCD) is a process where cells or tissues are broken down in an orderly and predictable manner, whereby nutrients are re-used by other cells, tissues or plant parts. The process of (petal) senescence shows many similarities to autophagic PCD in animal cells including a massive breakdown of protein, DNA and RNA, the formation of autophagic vacuoles for the breakdown of cytoplasm and organelles therein and, the eventual rupture of these vacuoles that kills the cell. Common storage disorders such as scald, internal browning, core breakdown and senescent breakdown in fruit and formation of a variety of storage-related problems in vegetables that are induced by severe conditions such as low temperature, low oxygen and increased carbon dioxide concentrations, are accompanied by death and sometimes disappearance of cells. This type of cell death shows similarities to autophagic cell death during aerenchyma formation in flooded roots. This paper discusses different types of cell death in relation to flower petal senescence and storage disorders in fruit and vegetables.