Responses of rubber tree seedlings (Hevea brasiliensis) to phosphorus deficient soils

While the adaptation and responses of model plants to phosphorus (P) deficiency are well documented, those of the rubber tree remain unclear. Here, we investigated above- and below-ground responses of rubber tree seedlings over the development of the first to third extension unit in a mesocosm system. Rubber tree seedlings were grown in high and low phosphorus soil for 7 months. Tissue nutrient contents, morphological, and physiological traits were quantified. We found that low P significantly reduced leaf P content, photosynthetic capabilities, and induced the accumulation of phenolic and flavonoid compounds, particularly in old leaves. Root traits were significantly affected by P stress early in their development. Root surface area and volume were increased through reduced lateral root branching and increased lateral root length. The alteration of root architectural traits took place prior to the reduction of P content in roots and leaves. Our findings provide new insights into rubber tree physiology and the effective fertilization management of rubber plantation in low P soils.

Automated summary

This study investigated the responses of rubber tree seedlings to high and low phosphorus (P) soils. It found that low P significantly reduced leaf P content and photosynthetic capabilities, and induced the accumulation of phenolic and flavonoid compounds in old leaves. Root traits were also significantly affected early on, with increased root surface area and volume through reduced lateral root branching and increased lateral root length. These findings provide new insights into rubber tree physiology and effective fertilization management in low P soils.