Effects of pruning and compost water extracts on root mitochondrial structure, root respiration, antioxidant system, and photosynthetic carbon transport

• Published in: Scientia horticulturae 2024-11, Vol.337, p.113546, Article 113546
• Main Authors: Li, Xiuli, He, Jiali, Tao, Ze, Qin, Sijun, Lyu, Deguo
• Format: Article
• Language: English
• Subjects: Compost; Debris; Extract; Photosynthetic parameters; Root respiration
• ISSN: 0304-4238
• DOI: 10.1016/j.scienta.2024.113546

•Composting pruned branches reduces toxicity and enhances organic liquid fertilizer production.•Higher amounts of pruned branch debris water extract elevate ROS content, inhibiting plant growth.•Water extraction from composted pruned branches augments antioxidant levels, preserving mitochondrial integrity.•Compost-derived water enhances root growth and boosts photosynthetic carbon metabolism, enabling sustainable agricultural practices. Transforming organic waste, such as pruning branches into compost and extracting water, can limit the levels of harmful substances in organic waste and decrease the spread of soil-borne diseases, critical for promoting sustainable agriculture. This study employed a pot experiment to examine the influence of water extraction from pruned branches or its compost on root respiration, mitochondrial structure, antioxidant system, and photosynthetic carbon metabolism. The findings demonstrated that the high concentration of pruning branches debris water extract (ST10) exhibited elevated ROS content in the roots and leaves, causing membrane lipid peroxidation, damaging mitochondrial structure, and inhibiting root growth. However, low-concentration pruned branch debris water extract (ST1) did not produce this phenomenon in seedlings. However, pruned branch debris can have its toxicity reduced after composting, and the extracted water can be used as a fast and efficient organic liquid fertilizer. The extracted water (CT1 and CT10) obtained from the composting of pruned branch debris increased the levels of SOD, POD, CAT, and APX and reduced O2•− and H2O2 production in the seedling roots. It also maintained the integrity of the mitochondria. Moreover, the CT1 and CT10 treatments elevated the total root respiration, increased the content of ATP and organic acid in the roots, and promoted root growth. Correspondingly, the CT10 treatment increased the photosynthetic rate and the content of soluble sugars in leaves and roots, offering adequate substrates for respiration, while the ST10 treatment decreased the content of soluble sugars in roots and leaves. These findings indicate that the composting of crushed branches can lower the toxicity of leaching solutions, promote plant growth, and enhance sustainable agricultural development.