Enzyme and Metabolite Profiles Spatial Distribution under Different Xylogenesis Scenarios in Karelian Birch

The actual study is the description of the biochemical characteristics of a wide range of enzymes (phenylalanine ammonia lyase, superoxide dismutase, catalase, peroxidase, polyphenol oxidase) and metabolites (malondialdehyde, phenols, extractives, cellulose, lignin), as well as the profiles of their activities during the xylem structural elements’ formation during the predominance of differentiation processes during straight-grained wood formation or proliferation while the figured wood formation in the radial row cambial zone (Fraction 1)—differentiating xylem (Fraction 2)—mature xylem (MX) in the period of active cambial growth in 16-year-old straight-grained Betula pendula var. pendula and figured Betula pendula var. carelica plants. We generalized the processes associated with abnormal xylogenesis were separated spatially, and, to the greatest extent, the metabolism of the studied birch forms differed in the Fraction 2, while the diagnostic contribution of secondary metabolism enzymes and malondialdehyde (MDA) probably characterized the active secondary metabolism of parenchyma cells, which formed figured wood basis. This study described for the first time the biochemical features of a wide range of enzymes and metabolites as well as the profiles of their activities in the xylem structural elements’ formation. The necessity of separately analyzing all tissue complexes was proven. This approach made possible to separate the generally observed biochemical patterns spatially. Thus, during the active cambial growth period in 16-year-old B. pendula var. pendula and B. pendula var. carelica, the differences between straight-grained plants and Karelian birch plants (non-figured and figured trunk parts) were most clearly expressed in the differentiating xylem.