Flowering time is an important agronomic trait, which is of great significance to the plant growth process. Salicylic acid (SA) is a key hormone that regulates plant growth and development. It can be converted into methyl salicylate (MeSA) catalyzed by SA carboxymethyl transferase (SAMT). Previous studies showed that SA was related to the regulation of plant flowering; however, the specific mechanism associated with this process remained to be further elucidated. In this study, the transgenic tobacco overexpressing LcSAMT gene and WT tobacco were cultivated to observe the flowering status of plant. The biomass and growth of tobaccos were recorded at different stages of plant growth. Endogenous MeSA content, phenylalanine ammonia-lyase (PAL) activity, and anthocyanin content were determined in transgenic tobacco plants during flowering stage. It was observed that the flowering time of transgenic tobacco was usually 6–7 days earlier than WT tobacco, and a higher endogenous MeSA content, PAL activity, and anthocyanin content were found in transgenic tobacco plants during flowering stage. Quantitative real-time PCR (qPCR) and transcriptome analysis were also performed in this study. There were 3924 differentially expressed genes (DEGs) identified between WT and transgenic tobacco plants by transcriptome analysis. These DEGs were primarily associated with plant hormone signal transduction pathways, plant pathogen interaction pathways, and mitogen-activated protein kinase (MAPK) pathways. QPCR analysis of 15 DEGs revealed that these genes were markedly upregulated in transgenic tobacco which was in accordance with transcriptome sequencing results. This study indicated that the SAMT gene-mediated SA homeostasis played important roles in the regulation of tobacco flowering.

开花时间是重要的农艺性状，对植物的生长过程具有重要意义。水杨酸（SA）是调节植物生长发育的关键激素。它可以被SA羧甲基转移酶（SAMT）催化转化为水杨酸甲酯（MeSA）。先前的研究表明，SA与植物开花的调控有关。然而，与此过程有关的具体机制还有待进一步阐明。在这项研究中，过表达LcSAMT的转基因烟草栽培该基因和野生烟草以观察植物的开花状态。在植物生长的不同阶段记录了烟草的生物量和生长。在开花期，测定了转基因烟草植物的内源MeSA含量，苯丙氨酸解氨酶（PAL）活性和花色苷含量。观察到，转基因烟草的开花时间通常比野生型烟草早6-7天，并且在开花期发现转基因烟草植物的内源MeSA含量，PAL活性和花色苷含量更高。这项研究还进行了定量实时PCR（qPCR）和转录组分析。通过转录组分析，在野生型和转基因烟草植物之间鉴定出3924个差异表达基因（DEG）。这些DEG主要与植物激素信号转导途径，植物病原体相互作用途径和有丝分裂原激活的蛋白激酶（MAPK）途径相关。对15个DEG的QPCR分析表明，这些基因在转基因烟草中显着上调，与转录组测序结果一致。这项研究表明SAMT基因介导的SA动态平衡在调节烟草开花中起着重要作用。