4.1. Planting Material and Growth Conditions

Pot experiment was conducted at the Ecological Farm of South China Agricultural University, Guangzhou, China (113°21′ E, 23°09′ N). Wild type rice (cv. Oochikara, WT) and Si-defective mutant rice (lsi1) were used in the study. This mutant was defective in active Si uptake. So, this rice was defined as a Si-defective mutant. Seeds were soaked for 30 min in 10% hydrogen peroxide, rinsed three times with deionized water, and then placed in incubator for 2 days at 80% humidity and 25℃ temperature. After germination, seedlings were transferred to a paddy field for growth. Plastic pots (upper diameter 27.5 × lower diameter 17.5 × height 20 cm) were filled with 5 kg of soil. Each pot was planted with three holes and two seedlings (fourth-leaf stage) planted in each hole. The basic properties of soil for pot experiments were as follows: pH 5.72, organic matter 18.36 g kg⁻¹, total N 1.16 g kg⁻¹, total P 0.61 g kg⁻¹, total K 9.72 g kg⁻¹, and available Si 147.28 mg kg⁻¹.