Key message

OsGTγ-2, a trihelix transcription factor, is a positive regulator of rice responses to salt stress by regulating the expression of ion transporters.

Abstract

Salinity stress seriously restricts rice growth and yield. Trihelix transcription factors (GT factors) specifically bind to GT elements and play a diverse role in plant morphological development and responses to abiotic stresses. In our previous study, we found that the GT-1 element (GAAAAA) is a key element in the salinity-induced OsRAV2 promoter. Here, we identified a rice OsGTγ family member, OsGTγ-2, which directly interacted with the GT-1 element in the OsRAV2 promoter. OsGTγ-2 specifically targeted the nucleus, was mainly expressed in roots, sheathes, stems and seeds, and was induced by salinity, osmotic and oxidative stresses and abscisic acid (ABA). The seed germination rate, seedling growth and survival rate under salinity stress was improved in OsGTγ-2 overexpressing lines (P_ZmUbi::OsGTγ-2). In contrast, CRISPR/Cas9-mediated OsGTγ-2 knockout lines (osgtγ-2) showed salt-hypersensitive phenotypes. In response to salt stress, different Na⁺ and K⁺ acclamation patterns were observed in P_ZmUbi::OsGTγ-2 lines and osgtγ-2 plants were observed. The molecular mechanism of OsGTγ-2 in rice salt adaptation was also investigated. Several major genes responsible for ion transporting, such as the OsHKT2; 1, OsHKT1; 3 and OsNHX1 were transcriptionally regulated by OsGTγ-2. A subsequent yeast one-hybrid assay and EMSA indicated that OsGTγ-2 directly interacted with the promoters of OsHKT2; 1, OsNHX1 and OsHKT1; 3. Taken together, these results suggest that OsGTγ-2 is an important positive regulator involved in rice responses to salt stress and suggest a potential role for OsGTγ-2 in regulating salinity adaptation in rice.

中文翻译：

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三螺旋转录因子OsGTγ-2与水稻对盐胁迫的适应有关。

关键信息

OsGTγ-2是一种三螺旋转录因子，通过调节离子转运蛋白的表达，是水稻对盐胁迫响应的正调节因子。

抽象的

盐分胁迫严重制约水稻生长和产量。Trihelix 转录因子 (GT 因子) 与 GT 元件特异性结合，并在植物形态发育和对非生物胁迫的反应中发挥多种作用。在我们之前的研究中，我们发现 GT-1 元件 (GAAAAA) 是盐度诱导的OsRAV2启动子中的关键元件。在这里，我们鉴定了一个水稻OsGTγ家族成员OsGTγ-2，它直接与OsRAV2中的 GT-1 元件相互作用。发起人。OsGTγ-2特异性靶向细胞核，主要在根、鞘、茎和种子中表达，并受盐度、渗透和氧化胁迫以及脱落酸（ABA）的诱导。OsGTγ-2过表达株系(P _ZmUbi ::OsGTγ-2 )的盐胁迫下种子发芽率、幼苗生长和成活率均有所提高。相比之下，CRISPR/Cas9 介导的 OsGTγ-2敲除系 ( osgtγ-2 ) 显示出盐过敏表型。针对盐胁迫，在 P _ZmUbi ::OsGTγ-2系和osgtγ-2中观察到不同的 Na ⁺和 K ^{+鼓掌模式}观察到植物。还研究了OsGTγ-2在稻盐适应中的分子机制。几个主要负责离子转运的基因，如OsHKT2；1、OsHKT1；3和OsNHX1受OsGTγ-2 的转录调控。随后的酵母单杂交试验和 EMSA 表明 OsGTγ-2 直接与 OsHKT2 的启动子相互作用。1、OsNHX1和OsHKT1；3 . 总之，这些结果表明 OsGTγ-2 是水稻对盐胁迫响应的重要正调节因子，并表明 OsGTγ-2 在调节水稻盐分适应中具有潜在作用。