Fig. 6. Organ- and tissue-specific expression analysis of td1. Organ-specific analysis of td1 transcription was carried out by quantitative real-time RT-PCR using endogenous ubiquitin transcript levels for normalization. Highest td1 transcript level is detected in the vegetative apex arbitrarily set to 100%. The RNA level is lower in the female inflorescence (58%). Low td1 transcript levels are detected in the embryo (11%) or the root (11%). A significant td1 transcript level is also detected in young leaves (63%). (B-F) In-situ expression pattern of td1 in shoot meristems at different stages of development. (B) Late vegetative shoot apex, showing td1 expression in developing leaves but also absence of detectable td1 expression in the SAM. (C) Tip of an ear primordium, showing weak td1 expression in the three outermost layers of the IM and td1 expression within SMs. (D) Tip of an ear primordium showing td1 expression in adaxial parts of the emerging SPMs. (E) Developing SM (stage F), showing expression within the SM and also in developing inner and outer glume and outer lemma primordia. (F) Upper and lower floral meristem (stage H): td1 is expressed strongly within the lower FM, but also in the developing ovule, silk and stamen primordia of the upper FM. Gi, inner glume; Go, outer glume; L, leaf; Lo, outer lemma; St, stamen primordium; S, silk primordium; O, ovule primordium; Pi, inner palea; LFM, lower floral meristem.