Abstract We studied the role of Trichoderma harzianum (TH) in improving the physiological, biochemical, hormonal, and molecular parameters of tomato seedlings grown under waterlogging (WL, for 14 and 28 days). Pretreatment with TH significantly improved the growth of tomato by enhancing the chlorophyll synthesis and uptake of essential ions, including nitrogen, phosphorus, and potassium. A reduction in anthocyanin content was also ameliorated significantly by TH pretreatment. TH significantly mitigated the WL-induced decline in height and in fresh and dry biomass accumulation. Accumulation of proline, flavonoids, anthocyanin, sugars, and soluble protein increased with TH pretreatment. At both growth periods (14 and 28 days after treatment [DAT]), the accumulation of secondary metabolites, including total phenols and flavonoids, and the redox components (tocopherols) were increased significantly by TH pretreatment. Increased synthesis of metabolites maintained the antioxidant status of tomato, resulting in amelioration of WL-induced oxidative effects on membranes. WL and TH treatments significantly increased ethylene production and decreased abscisic acid content at both growth periods. The accumulation of reactive oxygen species, like hydrogen peroxide, in TH treated seedlings was correlated with the upregulation of the Fe-SOD gene. WL stress triggered the activity of sucrose synthase (SUS), lactate dehydrogenase (LDH), and pyruvate decarboxylase (PDC), which reached a maximum at 14 DAT, and TH pretreatment resulted in further enhancement above control and WL-stressed levels. Quantitative RT-PCR revealed differential expression of genes, where Fe-SOD and ADH were upregulated due to TH treatment and ARE, ACO, ERF, and aquaporin were downregulated relative to control plants. Pretreatment of tomato seedlings with TH improved tolerance to WL by maintaining the antioxidant status, sugar metabolism, and expression of critical genes. These results suggest that TH pretreatment is an effective way to improve WL tolerance in tomato at vegetative stage.

中文翻译：

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用哈茨木霉预处理通过调节生理、生化和分子机制减轻番茄幼苗内涝引起的生长变化

摘要 我们研究了哈茨木霉 (TH) 在改善淹水条件下（WL，14 天和 28 天）生长的番茄幼苗的生理、生化、激素和分子参数方面的作用。TH预处理通过增强叶绿素合成和必需离子（包括氮、磷和钾）的吸收，显着改善了番茄的生长。TH预处理也显着改善了花青素含量的降低。TH 显着减轻了 WL 引起的高度下降以及新鲜和干生物量积累。脯氨酸、黄酮类化合物、花青素、糖类和可溶性蛋白质的积累随着 TH 预处理而增加。在两个生长期（治疗后 14 天和 28 天 [DAT]），次生代谢物的积累，包括总酚和黄酮类化合物，TH预处理显着增加了氧化还原成分（生育酚）。代谢物合成的增加维持了番茄的抗氧化状态，从而改善了 WL 诱导的细胞膜氧化作用。WL和TH处理显着增加了两个生育期的乙烯产量并降低了脱落酸含量。TH处理的幼苗中活性氧类（如过氧化氢）的积累与Fe-SOD基因的上调相关。WL 应激触发了蔗糖合酶 (SUS)、乳酸脱氢酶 (LDH) 和丙酮酸脱羧酶 (PDC) 的活性，在 14 DAT 时达到最大值，TH 预处理导致进一步增强，高于对照和 WL 应激水平。定量 RT-PCR 揭示基因的差异表达，其中 Fe-SOD 和 ADH 由于 TH 处理而上调，而 ARE、ACO、ERF 和水通道蛋白相对于对照植物下调。通过维持抗氧化状态、糖代谢和关键基因的表达，用 TH 预处理番茄幼苗提高了对 WL 的耐受性。这些结果表明TH预处理是提高番茄营养期WL耐受性的有效方法。