α-Mannosidase and β-D-N-acetylhexosaminidase outside the wall: partner exoglycosidases involved in fruit ripening process

Cell wall is a strong and complex net whose function is to provide turgor, pathogens attack protection and to give structural support to the cell. In growing and expanding cells, the cell wall of fruits is changing in space and time, because they are changing according to stage of ripening. Understand which mechanisms to produce significant could help to develop tools to prolong the fruit shelf life. Cell wall proteins (CWPs) with enzymatic activity on cell wall polysaccharides, have been studied widely. Another investigations take place in the study of N-glycosylations of CWPs and enzymes with activity on glycosidic linkages. alpha-mannosidase (alpha-Man; EC 3.2.1.24) and beta-d-N-acetylhexosaminidase (beta-Hex; EC 3.2.1.52), are enzymes with activity on mannose and N-acetylglucosamine sugar presents in proteins as part of N-glycosylations. Experimental evidence indicate that both are closely related to loss of fruit firmness, but in the literature, there is still no review of both enzymes involved fruit ripening. This review provides a complete state-of-the-art of alpha-Man and beta-Hex enzymes related in fruit ripening. Also, we propose a vesicular alpha-Man (EC 3.2.1.24) name to alpha-Man involved in N-deglycosylations of CWPs of plants.

Automated summary

The cell wall plays a crucial role in providing turgor, protection against pathogen attacks, and structural support to cells. Changes in the cell wall structure and composition during fruit ripening can affect fruit shelf life. In this review, the focus is on exploring the role of alpha-mannosidase and beta-d-N-acetylhexosaminidase enzymes in fruit ripening and fruit firmness.