Specific aspects of studying stem photosynthesis in perennial plants exemplified by the case of the grapevine

The structural organization and mechanisms of the photosynthetic apparatus in non-foliar organs remain poorly understood. This is particularly due to the lack of a reliable methodological foundation for an adequate and accurate assessment of the activity of photosynthetic processes in non-leaf chlorenchyma tissues, specifically due to the lack of knowledge regarding the susceptibility of the components of photosynthetic complexes to various environmental factors, including those encountered during the experimental procedure. This article examines the impact of different manipulation techniques applied during the experimental procedure on the activity of photosystem II (PSII) in grapevines of varying ages. The data obtained indicate a potential high sensitivity of the photosynthetic apparatus in chlorenchyma tissues of young vines to oxidative stress, which must necessarily be taken into account in analyses of vine chlorenchyma tissues accompanied by the removal of the outer layer of dead cells.