Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Sapienza Università di Roma, 00185 Rome, Italy.
Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, 00185 Rome, Italy.
Plant Cell. 2018 Mar;30(3):620-637. doi: 10.1105/tpc.17.00840. Epub 2018 Mar 7.
In addition to the full-length transcript , a splice variant () of the auxin response factor gene has been reported. Here, we identified an intron-retaining variant of , , whose translated product is imported into the nucleus and has tissue-specific localization in By inducibly expressing each variant in flowers, we show that fully complements the short-stamen phenotype of the mutant and restores the expression of , encoding a key regulator of stamen elongation. By contrast, the expression of and had minor or no effects on stamen elongation and expression. Coexpression of and in both the wild type and caused premature anther dehiscence: We show that is responsible for increased expression of the jasmonic acid biosynthetic gene and that is responsible for premature endothecium lignification due to precocious expression of transcription factor gene Finally, we show that ARF8.4 binds to specific auxin-related sequences in both the and promoters and activates their transcription more efficiently than ARF8.2. Our data suggest that ARF8.4 is a tissue-specific functional splice variant that controls filament elongation and endothecium lignification by directly regulating key genes involved in these processes.
除全长转录本外，生长素反应因子基因的剪接变异体 () 也已被报道。在这里，我们鉴定了一个内含子保留的变体， ，其翻译产物被导入细胞核，并在 中具有组织特异性定位。通过在 花中可诱导表达每种变体，我们表明 完全互补突变体的短雄蕊表型，并恢复编码雄蕊伸长关键调节剂的 的表达。相比之下， 和 的表达对 雄蕊伸长和 的表达几乎没有影响。 和 在野生型和 中的共表达导致花药过早开裂：我们表明 负责增加茉莉酸生物合成基因 的表达，并且 负责由于转录因子基因 的过早表达而导致的早期内皮层木质化。最后，我们表明 ARF8.4 结合到 和 启动子中的特定生长素相关序列，并比 ARF8.2 更有效地激活它们的转录。我们的数据表明，ARF8.4 是一种组织特异性的功能性剪接变体，通过直接调节参与这些过程的关键基因来控制细丝伸长和内皮层木质化。
