Sun Meihua, Li Jing, Tian Linlin, Sun Huixian, Miao Yanxiu, Bai Longqiang, Hou Leiping, Li Tianlai
College of Horticulture, Shanxi Agricultural University, Jinzhong 030801, China.
College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China.
Plants (Basel). 2025 Mar 18;14(6):952. doi: 10.3390/plants14060952.
Tomato seedlings were treated with nutrient solutions containing varying nitrogen concentrations (50, 150, and 250 mg·L) after germination until the completion of flower bud differentiation. The changes in nutrient content, enzyme activity, endogenous hormone levels, and gene expression in the stem apex were analyzed to explore the mechanisms regulating the number of locules in tomatoes at different nitrogen concentrations. The results indicated that an increase in nitrogen concentration facilitated the differentiation of tomato flower buds, increased the number of fruit locules, and increased the contents of soluble sugar, soluble protein, starch, and sucrose, as well as the activities of the enzymes POD, NR, and PPO in the seedling stem apex. The contents of soluble sugars and soluble proteins, as well as the activities of POD, NR, and PPO, were closely correlated with the number of fruit locules. An increase in nitrogen concentration was also found to elevate cytokinin levels while reducing auxin content in the stem apex. The transcriptome analysis screened for peroxidase genes, auxin response genes, and cytokinin synthesis genes. The analysis of gene expression patterns suggests that and play significant roles in flower development. Additionally, combined physiological changes indicated that an increase in nitrogen concentration during the tomato seedling stage leads to a higher number of fruit locules, which may be associated with elevated cytokinin content, primarily involving the key genes and .
番茄种子萌发后，用含不同氮浓度（50、150和250 mg·L）的营养液处理，直至花芽分化完成。分析茎尖中养分含量、酶活性、内源激素水平和基因表达的变化，以探究不同氮浓度下调控番茄心室数目的机制。结果表明，氮浓度的增加促进了番茄花芽的分化，增加了果实心室数，提高了幼苗茎尖中可溶性糖、可溶性蛋白、淀粉和蔗糖的含量，以及POD、NR和PPO酶的活性。可溶性糖和可溶性蛋白的含量以及POD、NR和PPO的活性与果实心室数密切相关。还发现氮浓度的增加会提高茎尖中细胞分裂素水平，同时降低生长素含量。转录组分析筛选出了过氧化物酶基因、生长素响应基因和细胞分裂素合成基因。基因表达模式分析表明， 和 在花发育中起重要作用。此外，综合生理变化表明，番茄幼苗期氮浓度的增加会导致果实心室数增多，这可能与细胞分裂素含量升高有关，主要涉及关键基因 和 。
