Contribution of the LAC Genes in Fruit Quality Attributes of the Fruit-Bearing Plants: A Comprehensive Review.

Laccase genes produce laccase enzymes that play a crucial role in the production of lignin and oxidation reactions within plants. Lignin is a complex polymer that provides structure and toughness to the cell walls of numerous fruit plants. The LAC genes that encode laccase enzymes play vital roles in plant physiology, including the synthesis of pigments like PA that contribute to the colors of fruits, and in defending against pathogens and environmental stresses. They are crucial for fruit development, ripening, structural maintenance in plants, and adaptation to various environmental factors. As such, these genes and enzymes are essential for plant growth and development, as well as for various biotechnological applications in environmental remediation and industrial processes. This review article emphasizes the significance of genes encoding laccase enzymes during fruit growth, specifically pertaining to the strengthening of the endocarp through lignification. This process is crucial for ensuring fruit defense and optimizing seed scattering. The information gathered in this article will aid breeders in producing future fruit-bearing plants that are resistant to disease, cost-effective, and nutrient-rich.

Ring Stripping, Ring Cutting, and Growth Regulators Promote Phase Change and Early Flowering in Pear Seedlings.

Hybrid breeding is the most important means of selecting pear (Pyrus) varieties, but a long juvenile period severely restricts the selection of new varieties. In this study, we used 'Yuluxiang' × 'Akituki' 4-year-old seedling trees to study the effects of plant growth regulators, ring stripping, and ring cutting on the promotion of phase change and flowering to assist in shortening the breeding cycle. A single application of 100 mg/kg 6-BA + 1000 mg/kg PP333 was most effective in promoting phase change and flowering. This treatment effectively inhibited the growth and thickening of annual shoots, significantly increased soluble sugar and protein contents in buds, increased the ABA content by 45.41%, decreased the IAA content by 7.35%, increased the expression of the flower-promoting genes FT and LFY by 2273.41% and 1153.71%, respectively, and decreased the expression of the flower-suppressing gene TFL1 by 74.92%. The flowering plant rate increased by 23.34% compared to the control. Both ring stripping and ring cutting were effective in promoting phase change and flowering, significantly increasing the flowering rate, inflorescence number, and the number of flowering plants. For improving the flowering rate, the ring-stripping treatment had the strongest effect and effectively inhibited the growth and thickening of annual shoots, while also significantly increasing the soluble sugar and protein contents in buds, reducing the contents of IAA and GA3 by 8.73% and 50.12%, respectively, increasing the expression of FT and LFY by 80.01% and 821.14%, respectively, and reducing the expression of the flower-suppressing gene TFL1 by 59.22%. In conclusion, ring stripping, ring cutting, and spraying of 100 mg/kg 6-BA + 1000 mg/kg PP333 were effective in promoting phase change and early flowering in seedling trees.