Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Ji'nan, 250014, China.
National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta of Shandong Province, Dongying, 257000, China.
J Integr Plant Biol. 2024 Apr;66(4):787-809. doi: 10.1111/jipb.13641. Epub 2024 Mar 13.
The recretohalophyte Limonium bicolor thrives in high-salinity environments because salt glands on the above-ground parts of the plant help to expel excess salt. Here, we characterize a nucleus-localized C3HC4 (RING-HC)-type zinc finger protein of L. bicolor named RING ZINC FINGER PROTEIN 1 (LbRZF1). LbRZF1 was expressed in salt glands and in response to NaCl treatment. LbRZF1 showed no E3 ubiquitin ligase activity. The phenotypes of overexpression and knockout lines for LbRZF1 indicated that LbRZF1 positively regulated salt gland development and salt tolerance in L. bicolor. lbrzf1 mutants had fewer salt glands and secreted less salt than did the wild-type, whereas LbRZF1-overexpressing lines had opposite phenotypes, in keeping with the overall salt tolerance of these plants. A yeast two-hybrid screen revealed that LbRZF1 interacted with LbCATALASE2 (LbCAT2) and the transcription factor LbMYB113, leading to their stabilization. Silencing of LbCAT2 or LbMYB113 decreased salt gland density and salt tolerance. The heterologous expression of LbRZF1 in Arabidopsis thaliana conferred salt tolerance to this non-halophyte. We also identified the transcription factor LbMYB48 as an upstream regulator of LbRZF1 transcription. The study of LbRZF1 in the regulation network of salt gland development also provides a good foundation for transforming crops and improving their salt resistance.
返盐植物二色补血草能在高盐环境中茁壮成长，因为植物地上部分的盐腺有助于排出多余的盐分。在这里，我们对二色补血草中的一种定位于核内的 C3HC4（RING-HC）型锌指蛋白 LbRZF1 进行了表征。LbRZF1 在盐腺中表达，并对 NaCl 处理有反应。LbRZF1 没有 E3 泛素连接酶活性。LbRZF1 过表达和敲除系的表型表明，LbRZF1 正向调控二色补血草的盐腺发育和耐盐性。lbrzf1 突变体的盐腺较少，分泌的盐分也少于野生型，而 LbRZF1 过表达系则表现出相反的表型，与这些植物的整体耐盐性一致。酵母双杂交筛选显示，LbRZF1 与 LbCATALASE2（LbCAT2）和转录因子 LbMYB113 相互作用，导致它们的稳定。LbCAT2 或 LbMYB113 的沉默降低了盐腺密度和耐盐性。LbRZF1 在拟南芥中的异源表达赋予了这种非盐生植物耐盐性。我们还鉴定了转录因子 LbMYB48 作为 LbRZF1 转录的上游调节剂。对 LbRZF1 在盐腺发育调控网络中的研究也为作物的转化和提高其耐盐性提供了良好的基础。
