2.7. In situ hybridization
Materials for in situ hybridization were sampled and immediately fixed in RNase-free FAA solution (4% formaldehyde, 10% aceticacid and 50% ethanol). Paraffin sections were obtained according to the method of Ma et al. [27]. A 68-bp fragment of OsLTPL36 cDNA was amplified from the seeds of the wildtype with the ISH-F and ISH-R primer (Table S5). The PCR product was cloned into pGM-Tvector (TaKaRa), which was digested with Pst I and Apa I. Subsequently, the product was transcribed in vitro under the control ofT7 or SP6 promoter with RNA polymerase using the DIG RNA labeling kit (Roche). The digoxigenin labeled antisense or sense RNA probe hybridization and immunological detection of the hybridizedprobes were performed using the procedure of Kouchi and Hata Finally, sections were photographed under Olympus BX53microscope using SPOT color camera.