Agricultural Biotechnology Institute, Epigenetics Group, National Agricultural Research and Innovation Center, Gödöllő, Hungary.
University of East Anglia, School of Biological Sciences, Norwich, UK.
Plant Cell Environ. 2018 Oct;41(10):2404-2417. doi: 10.1111/pce.13355. Epub 2018 Jul 26.
Plants substantially alter their developmental programme upon changes in the ambient temperature. The 21-24 nt small RNAs (sRNAs) are important gene expression regulators, which play a major role in development and adaptation. However, little is known about how the different sRNA classes respond to changes in the ambient temperature. We profiled the sRNA populations in four different tissues of Arabidopsis thaliana plants grown at 15°C, 21°C, and 27°C. We found that only a small fraction (0.6%) of the sRNA loci are ambient temperature-controlled. We identified thermoresponsive microRNAs and identified their target genes using degradome libraries. We verified that the target of the thermoregulated miR169, NF-YA2, is also ambient temperature-regulated. NF-YA2, as the component of the conserved transcriptional regulator NF-Y complex, binds the promoter of the flowering time regulator FT and the auxin biosynthesis gene YUC2. Other differentially expressed loci include thermoresponsive phased siRNA loci that target various auxin pathway genes and tRNA fragments. Furthermore, a temperature-dependent 24-nt heterochromatic siRNA locus in the promoter of YUC2 may contribute to the epigenetic regulation of auxin homeostasis. This holistic approach facilitated a better understanding of the role of different sRNA classes in ambient temperature adaptation of plants.
植物会根据环境温度的变化，大幅度改变其发育程序。21-24 个核苷酸的小 RNA（sRNA）是重要的基因表达调控因子，在发育和适应中发挥着主要作用。然而，对于不同的 sRNA 类别如何响应环境温度的变化，我们知之甚少。我们在生长于 15°C、21°C 和 27°C 的拟南芥的四个不同组织中对 sRNA 群体进行了分析。我们发现只有一小部分（0.6%）的 sRNA 基因座受到环境温度的控制。我们鉴定了热响应 microRNA，并使用降解组文库鉴定了它们的靶基因。我们验证了热调节 miR169 的靶标 NF-YA2 也是环境温度调节的。NF-YA2 作为保守转录因子 NF-Y 复合物的组成部分，与开花时间调节剂 FT 和生长素生物合成基因 YUC2 的启动子结合。其他差异表达的基因座包括靶向各种生长素途径基因和 tRNA 片段的热响应相 siRNA 基因座。此外，YUC2 启动子中一个与温度相关的 24 个核苷酸异染色质 siRNA 基因座可能有助于生长素稳态的表观遗传调控。这种整体方法有助于更好地理解不同 sRNA 类别在植物适应环境温度变化中的作用。
