Small RNAs (sRNAs) are a class of non-coding RNAs that consist of 21–24 nucleotides. They have been extensively investigated as critical regulators in a variety of biological processes in plants. sRNAs include two major classes: microRNAs (miRNAs) and small interfering RNAs (siRNAs), which differ in their biogenesis and functional pathways. Due to global warming, high-temperature stress has become one of the primary causes for crop loss worldwide. Recent studies have shown that sRNAs are involved in heat stress responses in plants and play essential roles in high-temperature acclimation. Genome-wide studies for heat-responsive sRNAs have been conducted in many plant species using high-throughput sequencing. The roles for these sRNAs in heat stress response were also unraveled subsequently in model plants and crops. Exploring how sRNAs regulate gene expression and their regulatory mechanisms will broaden our understanding of sRNAs in thermal stress responses of plant. Here, we highlight the roles of currently known miRNAs and siRNAs in heat stress responses and acclimation of plants. We also discuss the regulatory mechanisms of sRNAs and their targets that are responsive to heat stress, which will provide powerful molecular biological resources for engineering crops with improved thermotolerance.

小 RNA (sRNA) 是一类由 21-24 个核苷酸组成的非编码 RNA。它们已被广泛研究作为植物各种生物过程中的关键调节剂。sRNA 包括两大类：微 RNA (miRNA) 和小干扰 RNA (siRNA)，它们的生物发生和功能途径不同。由于全球变暖，高温胁迫已成为全球农作物损失的主要原因之一。最近的研究表明，sRNAs 参与植物的热应激反应，并在高温驯化中发挥重要作用。已经使用高通量测序在许多植物物种中对热响应 sRNA 进行了全基因组研究。这些 sRNA 在热应激反应中的作用随后在模型植物和作物中也被阐明。探索 sRNA 如何调控基因表达及其调控机制将拓宽我们对 sRNA 在植物热应激反应中的理解。在这里，我们强调了目前已知的 miRNA 和 siRNA 在热应激反应和植物驯化中的作用。我们还讨论了 sRNA 的调控机制及其响应热应激的靶标，这将为具有改进耐热性的工程作物提供强大的分子生物学资源。