盐胁迫是植物种子萌发与植株生长的重要限制因子。以羽衣甘蓝(Brassica oleracea var. acephala)名古屋为材料, 研究不同盐分对其种子萌发的影响, 探索水杨酸(SA)及其合成抑制剂氨基茚磷酸(AIP)处理对羽衣甘蓝种子萌发的调控效应。实验结果表明, 150与200 mmol·L ^-1 NaCl处理后的羽衣甘蓝种子活力显著降低。盐胁迫显著降低种子的吸水速率、种子活力与幼苗质量, 降低苯丙氨酸裂解酶活性与内源SA含量, 提高过氧化氢(H₂O₂)与超氧阴离子(O₂ ^-.)含量。SA可以缓解盐胁迫对羽衣甘蓝种子活力的抑制作用, 通过促进内源SA合成, 从而提高种子吸水率与种子活力, 促进种子对K ⁺、Mg ²⁺的吸收, 降低Na ⁺含量。此外, 外源施加SA能够显著增强超氧化物歧化酶和过氧化物酶活性, 降低H₂O₂与O₂ ^-.的积累。相反, 氨基茚磷酸(AIP)处理能够增强盐胁迫对种子萌发的抑制作用, 推测这与AIP处理能够显著降低种子内源SA含量密切相关。研究表明外源SA主要通过提高保护酶活性、降低活性氧积累和维持体内离子平衡来增强羽衣甘蓝的耐盐性。

Salinity is a major abiotic constraint affecting seed germination and plant growth. The effects of salt stress and salicylic acid (SA) and 2-aminoindan-2-phosphonic acid (SA synthesis inhibitor, AIP) on seed germination were investigated using kale (Brassica oleracea var. acephala) variety ‘Nagoya’. The results showed that the seed vigor of kale was significant decreased under 150 or 200 mmol·L ^-1 NaCl treatment by significantly reducing seed water uptake rate, seed vigor, and seedling quality, inhibited phenylalanine ammonia and lyase activity, decreasing endogenous SA content, and increasing hydrogen peroxide (H₂O₂) and superoxide anion (O₂ ^-.) contents. SA treatment effectively alleviated the inhibition of salt stress on seed germination, promoted endogenous SA anabolism, increased seed water absorption rate and seed vigor, promoted K ⁺ and Mg ²⁺ absorption, and reduced the Na ⁺ content. Furthermore, SA treatment significantly increased superoxide dismutase and peroxidase activities and inhibited H₂O₂ and O₂ ^-.accumulation. By contrast, AIP treatment significantly inhibited the germination process under salt stress, likely due to the reduced level of endogenous SA. This study demonstrates that exogenous SA enhances salt tolerance in kale seeds primarily through increasing the protective enzyme activities, reducing reactive oxygen species accumulation, and maintaining ion homeostasis during seed germination.