Smoke Water Promotes Root Meristem Activity and Cell Elongation but Inhibits Root Hair Growth Under Phosphorus Deficiency in Rice

The study investigates the effects of rice straw-derived smoke water on root growth in rice under phosphorus (P) deficiency. Smoke water enhances root elongation by promoting meristem activity and cell elongation, even under low P conditions. However, it suppresses root hair growth, reducing phosphate uptake rates. Smoke water improves phosphorus utilization efficiency and alters internal phosphorus allocation, increasing P accumulation in roots while decreasing it in shoots. These findings suggest that smoke water has a dual role in promoting root elongation and modulating P acquisition and allocation under nutrient stress, though its inhibitory effect on root hair elongation indicates a need for further refinement of its components.