Final answer:
Metabolic engineering was used to assess changes in plant metabolic pathways under hypoxia stress, key for survival by altering protein profiles and inducing antioxidant defenses, and engaging in cell wall reorganization. Specific changes such as the enzyme activity related to stress response and increased aerenchyma formation were pivotal findings.
Step-by-step explanation:
Metabolic engineering was utilized to demonstrate that pyrophosphate (PPi) helps potato plants survive hypoxia stress by examining the changes in metabolic pathways during such stress. Under hypoxic conditions, plants like the soybean activate specific pathways to manage the low oxygen environment. Proteomic analysis has shown that enzymes related to glycolysis and fermentation pathways, like alcohol dehydrogenase and pyruvate decarboxylase, are affected by stresses like flooding and low oxygen. The formation of aerenchyma in plant tissues, which facilitates oxygen transport from aerial parts to the submerged roots, is one adaptation that plants use to cope with flooding conditions.
Class III peroxidases, which are part of the plant's antioxidant system that mitigates oxidative stress caused by reactive oxygen species (ROS), have been found to play a significant role in managing hypoxia stress. Comprehensive proteomic studies on maize and tomato have highlighted differential expression of proteins linked to stress response, including those involved in antioxidant defenses. Various physiological parameters, such as the chlorophyll a/b ratio and shoot stem diameter, have also been used as markers to validate the typical responses of plants to flooding stress.
Overall, metabolic engineering involved assessing changes in protein profiles, such as peroxidase abundance and activity, to identify how plants alter their metabolic pathways to survive in low oxygen environments, primarily by reorganizing their cell wall structure and inducing antioxidant defenses.