Effects of phenolic compounds on enzyme activities involved in starch degradation, glyoxylate cycle and respiratory pathway during seed germination of Pinus laricio.

Phenolic compounds, which are of widespread occurrence in soils, can positively or negatively affect the growth and the development of vegetation. The phenolic acids in forest soils are derived mainly from the decomposition of plant residues and from synthesis by soil microorganisms. These compounds, termed commonly allelochemicals, influence many physiological processes, and have also an important ecological significance, being able to modify or to control processes such as succession or species interaction in nature. This review summarizes the progress made in recent years in understanding the activity of phenolic compounds extracted from soils with different vegetal cover on seed germination. In particular, we examined the biological effects of phenolic compounds on enzyme activities involved in starch degradation, on respiratory enzymes, oxidative pentose phosphate pathway, and glyoxylate cycle during seed germination of Pinus laricio [P. nigra], a typical tree of Southern Italy forests.