Effects on stone cell development and lignin deposition in pears by different pollinators

Area of Science:

• Plant Science
• Fruit Development
• Biochemistry

Background:

• Pear pulp develops from the ovary wall, genetically identical to the female parent.
• Paternal type significantly affects pear pulp quality, specifically stone cell clusters (SCCs) and their degree of polymerization (DP).
• Stone cells form via lignin deposition in parenchymal cell (PC) walls; pollination's effect on this process is unstudied.

Purpose of the Study:

• To investigate the impact of different paternal types on SCCs number, DP, and lignin deposition in pear fruit.
• To elucidate the mechanism of stone cell formation and lignification influenced by pollination.

Main Methods:

• Cross-pollination of 'Dangshan Su' pear (mother tree) with 'Yali' and 'Wonhwang' (father trees).
• Microscopic and ultramicroscopic observation to analyze SCCs number, DP, and lignin deposition.
• Comparative analysis of stone cell wall compactness and pit structure.

Main Results:

• SCC formation was consistent between pollination groups, but SCC number and DP were higher in the 'Yali' x 'Dangshan Su' (DY) group compared to the 'Wonhwang' x 'Dangshan Su' (DW) group.
• Lignification proceeded from cell corners to other regions, with lignin particles aligning along cellulose microfibrils.
• The cell wall layer compactness was significantly higher in DY than in DW, indicating greater resistance to PC expansion pressure.

Conclusions:

• Paternal type influences lignin deposition and stone cell characteristics in pear fruit.
• Higher DP and cell wall compactness in DY SCCs suggest a stronger resistance to parenchymal cell expansion.
• Understanding these effects is crucial for improving pear fruit quality and texture.