Kong Shuyao, Rusnak Byron, Zhu Mingyuan, Roeder Adrienne H K
Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA.
Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA.
Nat Commun. 2025 May 20;16(1):4682. doi: 10.1038/s41467-025-59943-4.
Cells display striking stochasticity in gene expression, which plays an important role in development, disease, and regeneration. Previous studies have found stochastic gene expression in bacteria, yeast, and from constitutive promoters in Arabidopsis. However, most promoters are non-constitutive. Stochastic gene expression from non-constitutive promoters in a multicellular organism, especially those with key developmental roles, remains largely uncharacterized. Here, we report stochastic expression of auxin responsive genes in the Arabidopsis floral meristem, using promoter reporters of DR5, ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN6 (AHP6), and DNA BINDING WITH ONE FINGER5.8 (DOF5.8). We find highly variable DR5 expression patterns among younger meristems. Such variability is largely attributed to stochastic expression of DR5, mainly influenced by cell-intrinsic molecular noise. Expression of AHP6 and DOF5.8 is also noisy, although their noise is lower and has distinct spatiotemporal patterns unlike DR5. Finally, we propose spatial averaging as a mechanism that buffers cellular gene expression noise, allowing the formation of robust global expression patterns. Our study reveals stochastic gene expression downstream of auxin signaling, a key developmental player. Thus, stochastic gene expression from non-constitutive promoters, including those involved in hormone signaling, is an ordinary part of multicellular life.
细胞在基因表达中表现出显著的随机性，这在发育、疾病和再生过程中发挥着重要作用。先前的研究已经在细菌、酵母以及拟南芥的组成型启动子中发现了随机基因表达。然而，大多数启动子是非组成型的。在多细胞生物中，尤其是那些具有关键发育作用的非组成型启动子的随机基因表达，在很大程度上仍未得到充分研究。在这里，我们利用DR5、拟南芥组氨酸磷酸转移蛋白6（AHP6）和单指DNA结合蛋白5.8（DOF5.8）的启动子报告基因，报道了拟南芥花分生组织中生长素响应基因的随机表达。我们发现在较年轻的分生组织中DR5表达模式高度可变。这种变异性很大程度上归因于DR5的随机表达，主要受细胞内在分子噪声的影响。AHP6和DOF5.8的表达也存在噪声，尽管它们的噪声较低，并且与DR5不同，具有独特的时空模式。最后，我们提出空间平均作为一种缓冲细胞基因表达噪声的机制，从而允许形成稳健的全局表达模式。我们的研究揭示了生长素信号下游的随机基因表达，生长素是关键的发育调控因子。因此，包括那些参与激素信号传导的非组成型启动子的随机基因表达，是多细胞生命的一个常见组成部分。
