Leaf chlorophyll assay
Homogenized leaf samples (300 mg) of the sitl1 and WT were used to determine chlorophyll content. Samples were incubated in 5 mL of 80% acetone in the dark for 30 min. After centrifugation at 15000 ×g for 15 min, supernatants were transferred to a 96-well microplate. The absorbance was measured at 645 and 663 nm using a SPECTROstarNano (BMG labtech, Germany) and chlorophyll a, b, and total chlorophyll content were calculated as described (Ma, Goto, Tamai, & Ichii, 2001).