【摘要】 采用不同氮浓度的营养液处理番茄幼苗，分析其茎尖内营养物质含量、酶活性、内源激素含量及基因表达变化，以探究不同供氮水平调控番茄心室数量的作用机制。结果显示，提高氮营养水平，可促进番茄花芽分化，增加果实心室数量和幼苗茎尖内可溶性蛋白质、淀粉、蔗糖、可溶性糖的含量及POD、NR、PPO酶活性，与果实心室数量密切相关的是可溶性蛋白质、可溶性糖含量及POD、NR、PPO活性；提高氮营养水平还增加了幼苗茎尖细胞分裂素、赤霉素、茉莉酸含量。转录组筛选出与花芽分化密切相关的过氧化物酶基因PRX44-like、PRX3-like和PRX66，赤霉素合成基因GA2ox2，细胞分裂素合成基因TLOG1、CKX2。结合生理指标变化，推测提高苗期氮营养水平，可能通过调控PRX44-like和GA2ox2基因表达，增加POD酶活性和赤霉素含量，进而影响番茄果实心室数量。更多还原

【Abstract】 Tomato seedlings were treated with nutrient solutions containing varying nitrogen concentrations. The nutrient content,enzyme activity,endogenous hormone levels,and gene expression changes in the shoot tips were analyzed to explore the mechanisms by which different nitrogen supply levels regulate the locule number of tomato fruit. The results indicate that increasing nitrogen nutrition levels accelerate tomato flower bud differentiation,increase the locule number of fruits and the content of soluble protein,starch,sucrose,and soluble sugar and enhances POD,NR,and PPO enzyme activities in the seedling stem tips. Closely related to the locule number of fruits is soluble protein,soluble sugar content and POD,NR and PPO activities. Furthermore,higher nitrogen nutrition levels lead to increased levels of cytokinins,gibberellins,and jasmonic acid in the stem tips. The transcriptome analysis revealed differentially expressed genes,including peroxidase genes PRX44-like,PRX3-like,and PRX66,alongside gibberellin synthesis gene GA2 ox2 and cytokinin synthesis genes TLOG1 and CKX2. Based on the observed physiological changes,it is speculated that enhancing nitrogen nutrition levels during the seedling stage may regulate the expression of PRX44-like and GA2 ox2 genes,thereby increasing POD enzyme activity and gibberellin content,ultimately influencing the locule number of tomato fruit.更多还原