Germ cells (GCs) transmit genetic information from one generation to the next. Unlike animal GCs, plant GCs are induced post-embryonically, forming locally from somatic cells. This induction is coordinated with organogenesis and might be guided by positional cues. In angiosperms, male GCs initiate from the internal layers at the four corners of the anther primordia and are gradually enclosed by parietal cell (PC) layers, leading to a concentric GC-PC pattern. However, the underlying mechanism of GC initiation and GC-PC pattern formation is unclear. Auxin affects pattern formation3 and anther development. However, whether GC formation involves auxin remains unknown. We report that the auxin distribution in pre-meiotic anthers parallels GC initiation, forming a centripetal gradient between the outer primordial cells and the inner GCs. The auxin biosynthesis genes TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (TAA1) and TRYPTOPHAN AMINOTRANSFERASE RELATED 2 (TAR2) are responsible for this patterning and essential for GC specification. SPOROCYTELESS/NOZZLE (SPL/NZZ, a determinant for GC specification) mediates the effect of auxin on GC specification, modulates auxin homeostasis, and maintains centripetal auxin patterning. Our results reveal that auxin is a key factor guiding GC specification in Arabidopsis anthers.

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生长素指导拟南芥花药中生殖细胞的规格

生殖细胞（GC）将遗传信息从一代传给下一代。与动物GC不同，植物GC是在胚胎后诱导的，由体细胞局部形成。这种诱导与器官发生相协调，并且可能受到位置提示的指导。在被子植物中，雄性GC从花药原基的四个角的内层开始，并逐渐被顶细胞（PC）层包围，从而形成同心的GC-PC模式。但是，GC启动和GC-PC模式形成的潜在机制尚不清楚。生长素会影响花序形成3和花药发育。但是，GC的形成是否涉及生长素仍是未知的。我们报告说，减数分裂前花药中的生长素分布平行于GC引发，在外部原始细胞和内部GC之间形成向心梯度。植物生长素的合成基因TABAP1的TRYPTOPHAN氨基酸转移酶（TAA1）和TRYPTOPHAN的AMT氨基酸转移酶相关2（TAR2）负责这种模式，并且对于GC规格至关重要。孢子/喷嘴（SPL / NZZ，GC规格的决定因素）介导生长素对GC规格的影响，调节植物生长素的稳态，并保持向心植物生长素的模式。我们的结果表明，生长素是指导拟南芥花药中GC规范的关键因素。并保持向心生长素的图案。我们的结果表明，生长素是指导拟南芥花药中GC规范的关键因素。并保持向心生长素的图案。我们的结果表明，生长素是指导拟南芥花药中GC规范的关键因素。