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 center dot- 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.

Resistance traits of plants can be activated both at the damaged site and undamaged parts. Systemic resistance induced by local exogenous abscisic acid (ABA) application alleviated negative effect of low water availability on growth performance of clonal plant. However, timing of systemic resistance was poorly understood. Timing of systemic resistance refers to its activation and decay time within clonal network. Clonal fragment of Centella asiatica with four successive ramets (including first-oldest, second-older, third-old and fourth-young ramets) subjected to low water availability (20% soil moisture content) was used to explore effects of local exogenous ABA application on the timing of resistance activation and decay. Systemic resistance activated by local exogenous ABA application after 4 days remained at least 28 days. Compared with control, biomass accumulation of whole clonal fragment, root biomass and ratio of belowground to aboveground biomass significantly increased by local exogenous ABA application after 28 days. It is suggested that rapid activation and delay of resistance response induced by local exogenous ABA application within clonal network may improve fitness of clonal plant subjected to abiotic stress.