PEG和NaCl胁迫下毛竹萌发种子中环状RNA特征及其表达研究

Expressional profiling of circRNAs under PEG and NaCl stresses in germinated moso bamboo seeds

【目的】环状RNA(circRNAs)是一类由转录本反向可变剪接产生的内源非编码RNA,在植物生长发育过程中具有重要作用。通过鉴定毛竹(Phyllostachys edulis)萌发期种子中的circRNAs,探究其在干旱和盐胁迫条件下的表达,为深入开展非生物胁迫条件下竹类植物种子萌发的分子调控机制提供基础。【方法】分别使用聚乙二醇(PEG)和NaCl模拟干旱和盐胁迫,构建H2O、10%(质量分数,下同)PEG、15%PEG、50 mmol/L NaCl和100 mmol/L NaCl处理下毛竹种皮破裂阶段种子的链特异性文库,通过高通量测序和生物信息学分析揭示样本中的circRNAs及其表达谱。【结果】所有样本中共鉴定了1446个circRNAs,76.34%的circRNAs来源于外显子区;不同处理下毛竹萌发种子中表达量最高的circRNA分别为plant_circ_0001703、plant_circ_0001728、plant_circ_0000358、plant_circ_0001236和plant_circ_0001728;与对照相比,524、505、467和474个circRNAs在4个胁迫处理下萌发的种子中显著差异表达;差异表达circRNAs的源基因显著富集在不同的GO条目和KEGG途径中。【结论】1446个circRNAs能够在毛竹萌发期种子中表达,其中有1056个circRNAs在种子萌发阶段响应了PEG或NaCl胁迫;作用于酸酐的水解酶活性和鞘脂代谢途径的基因可能对circRNAs调控PEG或NaCl胁迫下的毛竹种子萌发有重要意义。

【Objective】Circular RNAs(circRNAs)are a class of endogenous non-coding RNA produced by reverse alternative splicing of transcripts,which play crucial roles in plant growth and development.This study aimed to identify circRNAs in germinated seeds of moso bamboo(Phyllostachys edulis),and investigate their expression under drought and salt stress conditions,providing a foundation for exploring the molecular regulation mechanism of bamboo seed germination under abiotic stress resistance.【Method】polyethylene glycol(PEG)6000 and NaCl were used to simulate drought and salt stress,respectively.The strand specific libraries were constructed for moso bamboo seeds samples at the seed coat rupture stage under treatments of H2O,10%(mass fraction)PEG,15%PEG,50 and 100 mol/L NaCl.High throughout sequencing and biological information analysis were used to identify and analysis the expressional pattern of circRNAs.【Result】A total of 1446 circRNAs were identified in all samples,with 76.34%of circRNAs originating from exon region;The circRNAs with the highest expression levels in bamboo germinating seeds under different treatments were identified as plant_circ_0001703,plant_circ_0001728,plant_circ_0000358,plant_circ_0001236 and plant_circ_0001728;Compared with control,524,505,467 and 474 circRNAs were significantly differentially expressed in germinating seeds under the four stress treatments.The original genes of differentially expressed circRNAs were significantly enriched in various GO and KEGG pathways.【Conclusion】A total of 1446 circRNAs were found to be expressed in moso bamboo germinating seeds,with 1056 circRNAs responding to drought or salinity stresses during seed germination.Genes involved in acylhydrolase enzyme activity and sphingolipid metabolism pathways may play a crucial role in regulating bamboo seed germination under PEG or NaCl stress conditions.