Impact of phosphorus supply on root exudation, aerenchyma formation and methane emission of rice plants

This study evaluated the impact of P supply on rice plant development and the methane budget of rice fields by 2 different approaches: (1) root growth, exudation and aerenchyma formation were recorded in an experiment with hydroponic solution; (2) dissolved CH4 concentration and CH4 emission were investigated in a pot experiment. In both approaches, we used three different cultivars and three levels of P supply. In the experiment with solution culture (0.5 ppm, 5 ppm, and 10 ppm P), root exudation ranged between 0.5 to 36.7μmol C plant−1 h−1 and increased steadily with plant growth at given P level. Low P supply resulted in• depressed shoot growth but increased root growth in culture solution.• increments in the root/shoot ratio by factors of 1.4 to 1.9 at flowering stage.• enhanced the development of root aerenchyma, and• stimulation of root exudation per plant by factors of 1.3–1.8 as compared to medium P supply and by factors of 2.1–2.4 as compared to high P supply.