In flowering plants, the switch from floral stem cell maintenance to gynoecium (female structure) formation is a critical developmental transition for reproductive success. In Arabidopsis thaliana, AGAMOUS (AG) terminates floral stem cell activities to trigger this transition. Although CRABS CLAW (CRC) is a direct target of AG, previous research has not identified any common targets. Here, we identify an auxin synthesis gene, YUCCA4 (YUC4) as a common direct target. Ectopic YUC4 expression partially rescues the indeterminate phenotype and cell wall defects that are caused by the crc mutation. The feed-forward YUC4 activation by AG and CRC directs a precise change in chromatin state for the shift from floral stem cell maintenance to gynoecium formation. We also showed that two auxin-related direct CRC targets, YUC4 and TORNADO2, cooperatively contribute to the termination of floral stem cell maintenance. This finding provides new insight into the CRC-mediated auxin homeostasis regulation for proper gynoecium formation.

中文翻译：

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染色质分生组织确定性中的染色质介导的前馈生长素生​​物合成。

在开花植物中，从维持花干细胞到雌蕊结构（雌性结构）的转变是生殖成功的关键发展过渡。在拟南芥中，AGAMOUS（AG）终止了花干细胞的活性以触发这种转变。尽管CRABS CLAW（CRC）是AG的直接目标，但先前的研究尚未确定任何共同目标。在这里，我们确定了生长素合成基因YUCCA4（YUC4）作为常见的直接靶标。异位YUC4表达部分挽救了由crc突变引起的不确定的表型和细胞壁缺陷。由AG和CRC激活的前馈YUC4指导染色质状态的精确变化，从而实现了从花卉干细胞维持到雌蕊形成的转变。我们还显示了两个与生长素相关的直接CRC靶标YUC4和TORNADO2，共同有助于终止花卉干细胞的维持。这一发现提供了对CRC介导的植物生长素稳态调节以正确进行妇科形成的新见解。