Table_6_Comprehensive Analysis of Long Non-coding RNA Modulates Axillary Bud Development in Tobacco (Nicotiana tabacum L.).XLSX

Long non-coding RNAs (lncRNAs) regulate gene expression and are crucial for plant growth and development. However, the mechanisms underlying the effects of activated lncRNAs on axillary bud development remain largely unknown. By lncRNA transcriptomes of axillary buds in topped and untopped tobacco plants, we identified a total of 13,694 lncRNAs. LncRNA analysis indicated that the promoted growth of axillary bud by topping might be partially ascribed to the genes related to hormone signal transduction and glycometabolism, trans-regulated by differentially expressed lncRNAs, such as MSTRG.52498.1, MSTRG.60026.1, MSTRG.17770.1, and MSTRG.32431.1. Metabolite profiling indicated that auxin, abscisic acid and gibberellin were decreased in axillary buds of topped tobacco lines, while cytokinin was increased, consistent with the expression levels of related lncRNAs. MSTRG.52498.1, MSTRG.60026.1, MSTRG.17770.1, and MSTRG.32431.1 were shown to be influenced by hormones and sucrose treatments, and were associated with changes of axillary bud growth in the overexpression of NtCCD8 plants (with reduced axillary buds) and RNA interference of NtTB1 plants (with increased axillary buds). Moreover, MSTRG.28151.1 was identified as the antisense lncRNA of NtTB1. Silencing of MSTRG.28151.1 in tobacco significantly attenuated the expression of NtTB1 and resulted in larger axillary buds, suggesting the vital function of MSTRG.28151.1 axillary bud developmen by NtTB1. Our findings shed light on lncRNA-mRNA interactions and their functional roles in axillary bud growth, which would improve our understanding of lncRNAs as important regulators of axillary bud development and plant architecture.

长链非编码RNA（long non-coding RNAs，lncRNAs）可调控基因表达，对植物生长发育至关重要。然而，激活的lncRNAs对腋芽（axillary bud）发育的调控机制目前尚不完全明确。本研究通过对打顶与未打顶烟草植株腋芽的lncRNA转录组进行分析，共鉴定出13694条lncRNAs。LncRNA分析显示，打顶促进腋芽生长的现象可能部分归因于激素信号转导与糖代谢相关基因，这些基因受差异表达lncRNAs的反式调控，例如MSTRG.52498.1、MSTRG.60026.1、MSTRG.17770.1及MSTRG.32431.1。代谢组分析结果表明，打顶烟草植株腋芽中的生长素（auxin）、脱落酸（abscisic acid）与赤霉素（gibberellin）含量均下降，而细胞分裂素（cytokinin）含量上升，这与相关lncRNAs的表达水平一致。实验显示，MSTRG.52498.1、MSTRG.60026.1、MSTRG.17770.1及MSTRG.32431.1可受激素与蔗糖处理调控，且在NtCCD8过表达（腋芽数量减少）与NtTB1 RNA干扰（腋芽数量增加）的烟草植株中，这些lncRNAs的表达变化与腋芽生长改变密切相关。此外，本研究鉴定出MSTRG.28151.1为NtTB1的反义lncRNA。在烟草中沉默MSTRG.28151.1可显著抑制NtTB1的表达，并导致腋芽体积增大，提示MSTRG.28151.1通过调控NtTB1发挥其在腋芽发育中的关键功能。本研究结果阐明了lncRNA与mRNA的互作关系及其在腋芽生长中的功能作用，有助于加深我们对lncRNAs作为腋芽发育与植物株型（plant architecture）重要调控因子的认知。