BACKGROUND Jasmonic acid (JA) is an important molecule, has a regulatory effect on many physiological processes in plant growth and development under abiotic stress. This study investigated the effect of 60 μM of JA as priming (P) at 15 °C in darkness for 24 h, foliar (F) and/or their combination effect (P+F) on two soybean cultivars (Nannong 99-6 (salt tolerant) and Lee 68 (salt sensitive)) under salinity stress (100 mM NaCl). RESULTS Salinity stress reduced seedling growth and biomass as compared to that in the control condition. Priming and foliar application with JA and/or their combination significantly improved water potential, osmotic potential, water use efficiency (WUE) and relative water content (RWC) of both cultivars under salinity stress. Similarly, the priming, foliar application with JA and/or their combination significantly improved the net photosynthetic (Pn) by 68.03%, 59.85% and 76.67%; transpiration rate (Tr) by 74.85%, 55.10% and 80.26%; stomatal conductance (gs) by 69.88%, 78.25% and 26.24%; intercellular CO2 concentration (Ci) by 61.64%, 40.06% and 65.79% and total chlorophyll content (Chl) by 47.41%, 41.02% and 55.73%, respectively under salinity stress as compared to the untreated seedlings. Soybean plants primed, sprayed with JA or treated with their combination enhanced the chlorophyll fluorescence, which was damaged by salinity stress. JA treatments improved abscisic acid (ABA), gibberellic acid (GA) and JA levels by 60.57%, 62.50% and 52.25%, respectively under salt stress as compared to those in the control condition. The transcriptional levels of the FeSOD, POD, CAT and APX genes increased significantly in the NaCl-stressed seedlings irrespective of JA treatments. Moreover, JA treatment resulted in a reduction of Na+ concentration and an increase of K+ concentrations in the leaf and root of both cultivars regardless of salinity stress. Monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and proline contents decreased in the seedlings treated with JA under salinity stress, whereas the ascorbate (AsA) content increased with JA treatment combined with NaCl stress. CONCLUSION The application of 60 μM JA improved plant growth by regulating the interaction between plant hormones and hydrogen peroxide (H2 O2 ), which may involved in auxin signaling and stomatal closing under salt stress. These methods could efficiently protect early seedlings and alleviate salt stress damage and provide possibilities to be used for improving soybean growth and inducing tolerance against excessive soil salinity. This article is protected by copyright. All rights reserved.

中文翻译：

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茉莉酸种子引发和叶面喷施可增强大豆 (Glycine max L.) 幼苗的盐胁迫耐受性


背景技术茉莉酸(JA)是一种重要的分子，对非生物胁迫下植物生长发育的许多生理过程具有调节作用。本研究研究了 60 μM JA 作为引发剂 (P) 在 15 °C 黑暗条件下 24 小时、叶面处理 (F) 和/或其组合效应 (P+F) 对两个大豆品种（南农 99-6 (耐盐）和 Lee 68（盐敏感））在盐胁迫（100 mM NaCl）下。结果与对照条件相比，盐胁迫降低了幼苗的生长和生物量。 JA和/或其组合的引发和叶面施用显着提高了两个品种在盐胁迫下的水势、渗透势、水分利用效率（WUE）和相对含水量（RWC）。同样，JA和/或它们的组合的底涂、叶面施用显着提高了净光合（Pn）68.03%、59.85%和76.67%；蒸腾率（Tr）分别降低74.85%、55.10%和80.26%；气孔导度（gs）分别提高了69.88%、78.25%和26.24%；与未处理的幼苗相比，盐胁迫下细胞间CO2浓度（Ci）分别增加了61.64％、40.06％和65.79％，总叶绿素含量（Chl）分别增加了47.41％、41.02％和55.73％。用JA打底、喷洒或用它们的组合处理的大豆植物增强了叶绿素荧光，而叶绿素荧光因盐分胁迫而受损。与对照条件相比，盐胁迫下 JA 处理使脱落酸（ABA）、赤霉酸（GA）和 JA 水平分别提高了 60.57%、62.50% 和 52.25%。无论是否进行 JA 处理，在 NaCl 胁迫的幼苗中，FeSOD、POD、CAT 和 APX 基因的转录水平均显着增加。 此外，无论盐度胁迫如何，JA 处理都会导致两个品种的叶和根中 Na+ 浓度降低，K+ 浓度增加。盐胁迫下，JA处理的幼苗单脱氢抗坏血酸还原酶（MDHAR）、脱氢抗坏血酸还原酶（DHAR）和脯氨酸含量降低，而JA处理联合氯化钠胁迫则抗坏血酸（AsA）含量增加。结论 施用 60 μM JA 通过调节植物激素和过氧化氢 (H2 O2 ) 之间的相互作用来改善植物生长，这可能参与盐胁迫下的生长素信号传导和气孔关闭。这些方法可以有效保护早期幼苗，减轻盐胁迫损害，并为改善大豆生长和诱导土壤盐分过高的耐受性提供可能性。本文受版权保护。版权所有。