Arabidopsis thaliana TRY is a negative regulator of trichome differentiation that promotes root hair differentiation. Here, we established that LbTRY, from the recretohalophyte Limonium bicolor, is a typical MYB transcription factor that exhibits transcriptional activation activity and locates in nucleus. By in situ hybridization in L. bicolor, LbTRY may be specifically positioned in salt gland of the expanded leaves. LbTRY expression was the highest in mature leaves and lowest under NaCl treatment. For functional assessment, we heterologously expressed LbTRY in wild-type and try29760 mutant Arabidopsis plants. Epidermal differentiation was remarkably affected in the transgenic wild-type line, as was increased root hair development. Complementation of try29760 with LbTRY under both 35S and LbTRY specific promoter restored the wild-type phenotype. qRT-PCR analysis suggested that AtGL3 and AtZFP5 promote root hair cell fate in lines heterologously producing LbTRY. In addition, four genes (AtRHD6, AtRSL1, AtLRL2, and AtLRL3) involved in root hair initiation and elongation were upregulated in the transgenic lines. Furthermore, LbTRY specifically increased the salt sensitivity of the transgenic lines. The transgenic and complementation lines showed poor germination rates and reduced root lengths, whereas the mutant unexpectedly fared the best under a range of NaCl treatments. Under salt stress, the transgenic seedlings accumulated more MDA and Na+ and less proline and soluble sugar than try29760. Thus, when heterologously expressed in Arabidopsis, LbTRY participates in hair development, similar to other MYB proteins, and specifically reduces salt tolerance by increasing ion accumulation and reducing osmolytes. The expression of salt-tolerance marker genes (SOS1, SOS2, SOS3 and P5CS1) was significant reduced in the transgenic lines. More will be carried by downregulating expression of TRY homologs in crops to improve salt tolerance.

中文翻译：

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拟南芥中双色柠檬草 MYB 转录因子 LbTRY 的异源表达通过改变根毛发育和渗透稳态来增加盐敏感性

拟南芥 TRY 是毛状体分化的负调节因子，可促进根毛分化。在这里，我们确定来自潜生盐生植物 Limonium bicolor 的 LbTRY 是一种典型的 MYB 转录因子，表现出转录激活活性并位于细胞核中。通过在L. bicolor 中的原位杂交，LbTRY 可以特异性地定位在膨胀叶的盐腺中。LbTRY 表达在成熟叶片中最高，在 NaCl 处理下最低。对于功能评估，我们在野生型和 try29760 突变拟南芥植物中异源表达 LbTRY。表皮分化在转基因野生型品系中受到显着影响，根毛发育增加也是如此。在 35S 和 LbTRY 特异性启动子下，try29760 与 LbTRY 的互补恢复了野生型表型。qRT-PCR 分析表明 AtGL3 和 AtZFP5 在异源产生 LbTRY 的品系中促进根毛细胞命运。此外，参与根毛起始和伸长的四个基因（AtRHD6、AtRSL1、AtLRL2 和 AtLRL3）在转基因品系中上调。此外，LbTRY 特别增加了转基因品系的盐敏感性。转基因和互补品系显示出较差的发芽率和缩短的根长度，而突变体出人意料地在一系列 NaCl 处理下表现最佳。在盐胁迫下，转基因幼苗比 try29760 积累更多的 MDA 和 Na+ 以及更少的脯氨酸和可溶性糖。因此，当在拟南芥中异源表达时，LbTRY 参与毛发发育，类似于其他 MYB 蛋白，特别是通过增加离子积累和减少渗透物来降低耐盐性。耐盐标记基因（SOS1、SOS2、SOS3 和 P5CS1）在转基因株系中的表达显着降低。更多的将通过下调作物中 TRY 同源物的表达来提高耐盐性。