Salt stress has negative impact on plant development and growth. Jasmonic acid (JA), a phytohormone, has been shown to involve in salt-induced inhibition of primary root growth. The Arabidopsis Glucosinolate transporter1 (GTR1/NPF2.10) is characterized as a JA-Ile, a bioactive form of JA, transporter. However, whether GTR1 participates in salt responses is not clear. In this study, we confirmed that GTR1 is induced by both JA and salinity. Salt-induced JA signaling is affected in gtr1 mutant. The JA responsive genes, JAZ1, JAZ5, MYC2, LOX3, are down-regulated in gtr1 mutant. Phenotypic analyses showed that the salinity-induced lateral root growth inhibition is enhanced in gtr1 mutant, suggesting that GTR1 plays a positive role in lateral root development under salt stress. Interestingly, the expression of a Na+ transporter, HKT1, is upregulated in gtr1. Since HKT1 is a negative regulator for lateral root development under salt stress, we proposed that GTR1 alleviates the repression of lateral root development by salt stress by mediating JA signaling and repressing HKT1 expression. This study demonstrates that GTR1 is the molecular link between salt stress, JA signaling, and lateral root development.

中文翻译：

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芥子油苷转运蛋白1参与盐诱导的茉莉酸信号传导并减轻盐对拟南芥侧根生长的抑制

盐胁迫对植物的发育和生长有负面影响。茉莉酸 (JA) 是一种植物激素，已被证明与盐诱导的初生根生长抑制有关。拟南芥硫代葡萄糖苷转运蛋白 1 (GTR1/NPF2.10) 的特征是 JA-Ile，JA 转运蛋白的生物活性形式。然而，GTR1 是否参与盐反应尚不清楚。在这项研究中，我们证实 GTR1 是由 JA 和盐度诱导的。盐诱导的 JA 信号在 gtr1 突变体中受到影响。JA 响应基因 JAZ1、JAZ5、MYC2、LOX3 在 gtr1 突变体中下调。表型分析表明，gtr1 突变体中盐度诱导的侧根生长抑制增强，表明 GTR1 在盐胁迫下对侧根发育起积极作用。有趣的是，Na+ 转运蛋白 HKT1 的表达，在 gtr1 中上调。由于 HKT1 是盐胁迫下侧根发育的负调节因子，我们提出 GTR1 通过介导 JA 信号传导和抑制 HKT1 表达来减轻盐胁迫对侧根发育的抑制。这项研究表明 GTR1 是盐胁迫、JA 信号和侧根发育之间的分子联系。