Liu Qing-Lin, Xu Ke-Dong, Zhong Ming, Pan Yuan-Zhi, Jiang Bei-Bei, Liu Guang-Li, Jia Yin
Department of Ornamental Horticulture, Sichuan Agricultural University, Chengdu, China.
Key Lab of Plant Genetics & Molecular Breeding of Department of Life Science, Zhoukou Normal University, Zhoukou, China.
PLoS One. 2013 Dec 20;8(12):e83702. doi: 10.1371/journal.pone.0083702. eCollection 2013.
Plant vacuolar Na(+)/H(+) antiporter genes play significant roles in salt tolerance. However, the roles of the chrysanthemum vacuolar Na(+)/H(+) antiporter genes in salt stress response remain obscure. In this study, we isolated and characterized a novel vacuolar Na(+)/H(+) antiporter gene DgNHX1 from chrysanthemum. The DgNHX1 sequence contained 1920 bp with a complete open reading frame of 1533 bp encoding a putative protein of 510 amino acids with a predicted protein molecular weight of 56.3 kDa. DgNHX1 was predicted containing nine transmembrane domains. Its expression in the chrysanthemum was up-regulated by salt stress, but not by abscisic acid (ABA). To assess roles of DgNHX1 in plant salt stress responses, we performed gain-of-function experiment. The DgNHX1-overexpression tobacco plants showed significant salt tolerance than the wild type (WT). The transgenic lines exhibited more accumulation of Na(+) and K(+) under salt stress. These findings suggest that DgNHX1 plays a positive regulatory role in salt stress response.
植物液泡Na(+)/H(+)逆向转运蛋白基因在耐盐性方面发挥着重要作用。然而，菊花液泡Na(+)/H(+)逆向转运蛋白基因在盐胁迫响应中的作用仍不清楚。在本研究中，我们从菊花中分离并鉴定了一个新的液泡Na(+)/H(+)逆向转运蛋白基因DgNHX1。DgNHX1序列包含1920 bp，有一个1533 bp的完整开放阅读框，编码一个推定的含510个氨基酸的蛋白质，预测蛋白质分子量为56.3 kDa。预测DgNHX1含有9个跨膜结构域。其在菊花中的表达受盐胁迫上调，但不受脱落酸（ABA）上调。为了评估DgNHX1在植物盐胁迫响应中的作用，我们进行了功能获得实验。过表达DgNHX1的烟草植株比野生型（WT）表现出显著的耐盐性。转基因株系在盐胁迫下表现出更多的Na(+)和K(+)积累。这些发现表明DgNHX1在盐胁迫响应中起正向调节作用。
