Leaf contents of intermediates and expression levels of key genes in the salvage pathway. A, Leaf contents of nicotinate (Na), nicotinamide (Nam), and NAD in 40-d-old wild-type and lts1 plants. Data are the mean values. Error bars refer to sd of three biological repeats. **P ≤ 0.01; Student’s t test. FW, fresh weight. B, Leaf expressional levels of OsNIC, OsSRT1, and OsSRT2 in lts1 plants at 30, 50, and 70 d postgermination. The corresponding transcription levels of genes in the wild-type plants were set at 1.0. Data are the mean values. Error bars refer to sd of three biological repeats.