Question

Some plants with genetic defects to Rubisco are unable to photorespire properly due to an inability to bind to excess oxygen that tends to build up when stomata close. These plants have been observed to have cellular damage under these conditions. Researches identify this as evidence that photorespiration is a protective mechanism in plants and not a wasteful process. Why might a disabling of the photorespiratory pathway lead to cell damage and how might the process of photorespiration reduce this damage?

Answer 1

The photorespiratory pathway would be consisting of nitrogen cycle as well as the carbon cycle, that would carry out metabolism of glycolate 2 phosphate towards the Calvin cycle. As a result of this, there would b a prevention ofphotoinhibition of the PSII. This is more important in th C3 plants. If there is an inhibition of the photorespiratory pathway, there would be an acceleration of PSII photorespiration. Photo inhibition is the process by which there would be absorption of light in order to carry out photosynthesis. This light absorption leads to damage of the machinery for photosynthesis.

As a result of this impairment, there would be suppression of the repair mechanisms, as a result of which the damaged cells will not be able to get fixed. THis is because there would be inhibition of the D1 protein’s de novo synthesis.