Accumulation of Sugars and Liquid in Apoplast of Fruit Flesh Result in Pineapple Translucency

Abstract

Translucency is a recurring problem for pineapple industry. Translucent fruit contained more sucrose, glucose and fructose in apoplast than those in apoplast of normal fruit. There were more liquid in intercellular space of translucent fruit than that of normal flesh. The contents of alcohol and ethylene in translucent fruit were higher than those in normal fruit. Translucent fruit contained less calcium than normal fruit. Electrolyte leakage of translucent flesh was more than that of normal flesh. There were 205 proteins of which the expressions in translucent flesh were higher than those in normal flesh. Calcium-ions-binding protein EF-hand domain-containing protein, ethy lene-synthesizing enzyme 1-aminpcyclopropane-1-carboxylate oxidase, ROS-producing protein universal stress protein A-like protein were the top three proteins of which the expressions in translucent flesh were higher than those in normal fruit. When much sugar was transferred into fruit pulp and accumulated in intercellular space, water will be absorbed from cells around and translucence formed. The accumulation of sugar and liquid in apoplast were due to that cell wall and membrane were degraded, which was from being attacked by ROS. There might be more and larger pores in cell wall and membranes of translucent flesh. These data played foundations for researching methods for controlling pineapple translucency.