Wang Shengji, Huang Juanjuan, Wang Xingdou, Fan Yan, Liu Qiang, Han Youzhi
College of Forestry, Shanxi Agricultural University, Jinzhong, China.
College of Forestry, Hebei Agricultural University, Baoding, China.
Front Plant Sci. 2021 Jun 4;12:669143. doi: 10.3389/fpls.2021.669143. eCollection 2021.
The aggravation of soil salinization limits the growth and development of plants. The AP2/ERF transcription factors (TFs) have been identified and play essential roles in plant development and stress response processes. In this study, the function of was detected using the overexpressing (OX) and RNAi transgenic poplar 84K hybrids. Plant growth, stomatal conductance, antioxidant enzymes activity, and co-expressed were analyzed using morphological, physiological, and molecular methods. OX showed a more robust lateral root system with a bigger diameter and volume compared to the wild-type plants (WT). Physiological parameters indicated the bigger stomatal aperture and lower stomatal density of OX along with the lower Catalase (CAT) activity and higher malondialdehyde (MDA) content contributed to the salt sensitivity. The plant height and rooting rate of OX and RNAi were significantly worse compared to WT. Other than that, the morphology and physiology of RNAi plants were similar to WTs, suggesting that the function of may be redundant with other TFs. Our results indicate that when expression is either too high or too low, poplar growth and rooting is negatively affected. In addition, a downstream target TF, NAC45, involved in Auxin biosynthesis, was identified and could directly bind to its promoter to negatively regulate its expression. These results shed new light on the function of ERF TFs in plant root growth and salt stress tolerance.
土壤盐渍化的加剧限制了植物的生长发育。AP2/ERF转录因子（TFs）已被鉴定出来，并在植物发育和胁迫响应过程中发挥重要作用。在本研究中，使用过表达（OX）和RNA干扰转基因84K杨树杂种检测了[具体基因名称缺失]的功能。采用形态学、生理学和分子生物学方法分析了植物生长、气孔导度、抗氧化酶活性以及[具体内容缺失]共表达情况。与野生型植株（WT）相比，OX表现出更发达的侧根系统，侧根直径和体积更大。生理参数表明，OX的气孔孔径较大，气孔密度较低，同时过氧化氢酶（CAT）活性较低，丙二醛（MDA）含量较高，这些因素导致其对盐敏感。与WT相比，OX和RNA干扰植株的株高和生根率显著更低。除此之外，RNA干扰植株的形态和生理特征与WT相似，这表明[具体基因名称缺失]的功能可能与其他TFs冗余。我们的结果表明，当[具体基因名称缺失]表达过高或过低时，杨树的生长和生根都会受到负面影响。此外，还鉴定出一个参与生长素生物合成的下游靶标TF，即NAC45，并且[具体基因名称缺失]可以直接结合其启动子以负向调节其表达。这些结果为ERF TFs在植物根系生长和耐盐胁迫中的功能提供了新的见解。
