Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, 572025, Sanya, P. R. China.
Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants, Ministry of Education/Engineering Research Center of Rare and Precious Tree Species in Hainan Province, School of Forestry, Hainan University, 570228, Haikou, P. R. China.
BMC Genomics. 2022 Aug 16;23(1):596. doi: 10.1186/s12864-022-08836-7.
Explored the molecular science of anther development is important for improving productivity and overall yield of crops. Although the role of regulatory RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), in regulating anther development has been established, their identities and functions in Camellia oleifera, an important industrial crop, have yet not been clearly explored. Here, we report the identification and characterization of genes, lncRNAs and miRNAs during three stages of the tropical C. oleifera anther development by single-molecule real-time sequencing, RNA sequencing and small RNA sequencing, respectively.
These stages, viz. the pollen mother cells stage, tetrad stage and uninucleate pollen stage, were identified by analyzing paraffin sections of floral buds during rapid expansion periods. A total of 18,393 transcripts, 414 putative lncRNAs and 372 miRNAs were identified, of which 5,324 genes, 115 lncRNAs, and 44 miRNAs were differentially accumulated across three developmental stages. Of these, 44 and 92 genes were predicted be regulated by 37 and 30 differentially accumulated lncRNAs and miRNAs, respectively. Additionally, 42 differentially accumulated lncRNAs were predicted as targets of 27 miRNAs. Gene ontology enrichment indicated that potential target genes of lncRNAs were enriched in photosystem II, regulation of autophagy and carbohydrate phosphatase activity, which are essential for anther development. Functional annotation of genes targeted by miRNAs indicated that they are relevant to transcription and metabolic processes that play important roles in microspore development. An interaction network was built with 2 lncRNAs, 6 miRNAs and 10 mRNAs. Among these, miR396 and miR156 family were up-regulated, while their targets, genes (GROWTH REGULATING FACTORS and SQUAMOSA PROMOTER BINDING PROTEIN-LIKE genes) and lncRNAs, were down-regulated. Further, the trans-regulated targets of these lncRNAs, like wall-associated kinase2 and phosphomannose isomerase1, are involved in pollen wall formation during anther development.
This study unravels lncRNAs, miRNAs and miRNA-lncRNA-mRNA networks involved in development of anthers of the tropical C. oleifera lays a theoretical foundation for further elucidation of regulatory roles of lncRNAs and miRNAs in anther development.
探索花粉囊发育的分子科学对于提高作物的生产力和总体产量至关重要。虽然调控 RNA（包括长非编码 RNA（lncRNA）和 microRNA（miRNA））在调控花粉囊发育中的作用已经确立，但它们在重要工业作物油茶中的身份和功能尚未得到明确探索。在这里，我们通过单分子实时测序、RNA 测序和小 RNA 测序分别报告了热带油茶花粉囊发育三个阶段的基因、lncRNA 和 miRNA 的鉴定和特征。
通过分析快速膨胀期花蕾的石蜡切片，确定了这三个阶段，即花粉母细胞阶段、四分体阶段和单核花粉阶段。共鉴定出 18393 个转录本、414 个推定的 lncRNA 和 372 个 miRNA，其中 5324 个基因、115 个 lncRNA 和 44 个 miRNA 在三个发育阶段差异积累。其中，44 个和 92 个基因分别被预测受到 37 个和 30 个差异积累的 lncRNA 和 miRNA 的调控。此外，42 个差异积累的 lncRNA 被预测为 27 个 miRNA 的靶标。基因本体富集分析表明，lncRNA 的潜在靶基因富集在光系统 II、自噬调节和碳水化合物磷酸酶活性中，这些对花粉囊发育至关重要。miRNA 靶基因的功能注释表明，它们与转录和代谢过程相关，这些过程在小孢子发育中发挥重要作用。构建了一个包含 2 个 lncRNA、6 个 miRNA 和 10 个 mRNA 的相互作用网络。其中，miR396 和 miR156 家族上调，而它们的靶基因（生长调节因子和 SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 基因）和 lncRNA 下调。此外，这些 lncRNA 的反调控靶标，如壁激酶 2 和磷酸甘露糖异构酶 1，参与了花粉囊发育过程中的花粉壁形成。
本研究揭示了参与热带油茶花粉囊发育的 lncRNA、miRNA 和 miRNA-lncRNA-mRNA 网络，为进一步阐明 lncRNA 和 miRNA 在花粉囊发育中的调控作用奠定了理论基础。
