Blackberry fruit is rich in bioactive substances and has antioxidant function, with broad market prospects. However, most blackberry cultivars have prickles all over their bodies, which is highly inconvenient for the management and harvesting. This study revealed that the content of lignin and PAL, an enzyme which related to lignin synthesis increases with the occurrence of prickles. The miRNA expression profiles and potential target gene regulation patterns of the cortex and stem tips of the thorny blackberry cultivar 'Boysenberry' and its bud-mutated thornless cultivar 'Zaohong' cortex were obtained through small RNA sequencing. This study identified a total of 50 differentially expressed miRNAs. The target genes of these differentially expressed miRNAs play important roles in the phenylalanine synthesis and plant hormone signal transduction pathway. Novel_151-CAD, fve-miR396b-5p-CAD, fve-miR396b-5p-POD, fve-miR396a-5p-POD genes can increase lignin production, while novel_186-GUAT, fve-miR164a-5p-UXS genes can increase cell wall polysaccharides production, and thus promote the formation of cell wall. Novel_159-AUX/IAA, fve-miR159b-AUX/IAA and novel_128-AUX/IAA genes can affect lignin production by activating the auxin signaling pathway. Those genes may play important regulatory roles in the occurrence of blackberry prickle. The results will provide a reference for the research on blackberry prickle, and lay the foundation for breeding cultivars without prickle and the development of blackberry industry.

中文翻译：

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在 Rubus spp 刺发育过程中鉴定 microRNA 及其下游转录调控网络


黑莓果实含有丰富的生物活性物质，具有抗氧化功能，市场前景广阔。然而，大多数黑莓品种全身都有刺，这对管理和收获非常不方便。这项研究表明，木质素和 PAL（一种与木质素合成相关的酶）的含量随着刺的发生而增加。通过小 RNA 测序获得带刺黑莓品种 'Boysenberry' 及其芽突变的无刺品种 '早红' 皮层皮层和茎尖的 miRNA 表达谱和潜在的靶基因调控模式。本研究共鉴定出 50 个差异表达的 miRNA。这些差异表达的 miRNAs 的靶基因在苯丙氨酸合成和植物激素信号转导途径中起重要作用。Novel_151-CAD、fve-miR396b-5p-CAD、fve-miR396b-5p-POD、fve-miR396a-5p-POD 基因可以增加木质素的产生，而 novel_186-GUAT、fve-miR164a-5p-UXS 基因可以增加细胞壁多糖的产生，从而促进细胞壁的形成。Novel_159-AUX/IAA、fve-miR159b-AUX/IAA 和 novel_128-AUX/IAA 基因可通过激活生长素信号通路影响木质素的产生。这些基因可能在黑莓刺的发生中发挥重要的调节作用。研究结果将为黑莓刺的研究提供参考，为无刺品种的选育和黑莓产业的发展奠定基础。