In the context of organic farming, the introduction of a local product to wider markets and an evaluation of storage effects, metabolic and transcriptomic variations in two broccoli rabe genotypes from production cycles of two different years were studied by comparing florets of stored fresh (SF) and packaged (P) for 4 days with those harvested fresh from the field (H). Twenty-five hydrosoluble compounds, including amino acids, carbohydrates, and organic acids, were quantified by untargeted NMR. PCA produced a neat separation among the three commodity statuses with P being the most divergent and SF closer to H. In the packaged florets, carbohydrate levels dropped significantly (over -52%), while the levels of amino acids and organic acids varied. There was an increase in stress-responsive phenylalanine and valine (over 30%) and succinic and α-ketoglutaric acids (over 75%). Compound correlation analyses indicated a carbohydrate sink towards γ-aminobutyric acid (GABA) and lactic acid (LA) metabolism under hypoxic conditions in packaged florets. RNA-seq analysis revealed that over 4000 genes were differentially expressed in SF vs H and 8000 in P vs H. Several CAR and AA pathways were significantly enriched in S and even more significantly in P, when compared to H. A map of gene expression (175 genes) and metabolite contents (14 compounds) was constructed to elucidate the gene routes that lead to accumulation of GABA and LA, known for healthy properties, in P. WGCNA and promoter binding site analyses enabled the identification of transcription factors (bZIP, WRKY, ERF types), interactions, and targeted genes encoding key enzymes in GABA and LA accumulation.

中文翻译：

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导致新鲜或最低限度加工产品储存的有机西兰花拉贝（Brassica rapa subsp. sylvestris）小花中 GABA 和乳酸积累的分子途径


在有机农业的背景下，通过比较新鲜储存（SF）的小花，研究了将当地产品引入更广泛的市场，并评估了两个不同年份生产周期中两种西兰花拉贝基因型的储存效果、代谢和转录组变异。并与从田间新鲜收获的 (H) 一起包装 (P) 4 天。通过非靶向 NMR 定量了 25 种水溶性化合物，包括氨基酸、碳水化合物和有机酸。 PCA 在三种商品状态之间产生了清晰的分离，其中 P 差异最大，SF 更接近 H。在包装的小花中，碳水化合物水平显着下降（超过 -52%），而氨基酸和有机酸的水平各不相同。应激反应性苯丙氨酸和缬氨酸（超过 30%）以及琥珀酸和 α-酮戊二酸（超过 75%）增加。化合物相关分析表明，在包装小花的缺氧条件下，碳水化合物向 γ-氨基丁酸 (GABA) 和乳酸 (LA) 代谢下沉。 RNA-seq 分析显示，超过 4000 个基因在 SF 与 H 中存在差异表达，在 P 与 H 中存在 8000 个差异表达。多个 CAR 和 AA 通路在 S 中显着富集，与 H 相比，在 P 中更为显着。基因表达图谱构建了（175 个基因）和代谢物含量（14 种化合物），以阐明导致 GABA 和 LA（以健康特性而闻名）在 P.WGCNA 和启动子结合位点分析中积累的基因途径，从而能够鉴定转录因子（bZIP、 WRKY、ERF 类型）、相互作用以及编码 GABA 和 LA 积累关键酶的目标基因。