Zheng Longyan, Zhang Wenhao, Wei Liuqing, Li Mengqi, Liu Li
Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China.
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China.
Plants (Basel). 2025 Mar 18;14(6):950. doi: 10.3390/plants14060950.
The Squamosa promoter-binding protein-like (SPL) family proteins plays pivotal roles in plant development and stress adaptation. In this study, we functionally characterized in mulberry () and investigated its regulatory roles in biotic and abiotic stress responses. encodes a 364-amino acid protein with a conserved SBP domain and lacks binding sites. Phylogenetic analysis confirmed its orthology to AtSPL8, albeit with functional divergence. Downregulation of via virus-induced gene silencing (VIGS) resulted in more susceptibility to infection, but significantly enhanced resistance to drought and salt stress, as evidenced by reduced oxidative damage, elevated proline accumulation, and increased antioxidant enzyme activities. Transcriptomic profiling of -silenced plants revealed enrichment of differentially expressed genes (DEGs) in brassinosteroid biosynthesis, jasmonic acid metabolism, and oxidative stress responses, suggesting hormone signaling interplay. Furthermore, bioinformatic predictions identified and as potential post-transcriptional regulators of . This study highlights as a negative regulator of abiotic stress tolerance and positive regulator of biotic () stress tolerance in mulberry and provides insights into its integration with phytohormone pathways. Our findings underscore the evolutionary plasticity of genes and propose as a target for enhancing mulberry's resilience in challenging environments.
类Squamosa启动子结合蛋白（SPL）家族蛋白在植物发育和胁迫适应中起关键作用。在本研究中，我们对桑树中的该蛋白进行了功能鉴定，并研究了其在生物和非生物胁迫响应中的调控作用。该蛋白编码一个含有保守SBP结构域的364个氨基酸的蛋白质，并且缺乏结合位点。系统发育分析证实了其与拟南芥AtSPL8的直系同源关系，尽管存在功能差异。通过病毒诱导基因沉默（VIGS）下调该蛋白导致对感染更敏感，但显著增强了对干旱和盐胁迫的抗性，这通过减少氧化损伤、提高脯氨酸积累和增加抗氧化酶活性得以证明。对沉默该蛋白的植物进行转录组分析揭示了在油菜素类固醇生物合成、茉莉酸代谢和氧化应激反应中差异表达基因（DEG）的富集，表明激素信号相互作用。此外，生物信息学预测确定了该蛋白和其他蛋白作为其潜在的转录后调节因子。本研究突出了该蛋白作为桑树中非生物胁迫耐受性的负调节因子和生物（）胁迫耐受性的正调节因子，并提供了其与植物激素途径整合的见解。我们的研究结果强调了该蛋白基因的进化可塑性，并提出将其作为提高桑树在具有挑战性环境中的恢复力的靶点。
