Glycolysis Fermentative By-Products and Secondary Metabolites Involved in Plant Adaptation under Hypoxia during Pre- and Postharvest

Abstract

Floods inducing hypoxia (reduction of available O 2 ) in the plants are current major constrains for agricultural production. Oxygen deficiency in the plant cells induces the secondary response of anatomical and physiological modifications. Hypoxia triggers glycolysis fermentative pathway and other alternative pathways, when the plant lacks energy. During cultivation, some submerged plants can adapt themselves to survive by modifying some parenchyma cells in the roots to be aerenchyma cells to detain available oxygen for oxidative phosphorylation. Furthermore, carbon sources in the cells will be accumulated in N store that recovers back to a C source at the end of hypoxia. In postharvest, long period in modified atmosphere storage could activate hypoxia in the plant parts that produce off-flavor perception. However, in some fruits at a particular maturity, etha -nol, a hypoxic product, can be modified into ethyl ester compounds as the detoxification. tolerant plants are depended on types of plants, maturities, and degrees of hypoxia. Plant defensive mechanisms under hypoxia are signaled mainly by increasing endogenous H 2 O 2 and/or ethylene, which are responsible for cascade controls of further endogenous hormones. The responses include an increase in cell wall lignification, different changes in cell wall component, and the production of hypoxic by-products such as fermentative mediate, N-store, and ethyl ester compounds.