NAC (no apical meristem [NAM], Arabidopsis thaliana transcription activation factor [ATAF1/2], and cup-shaped cotyledon [CUC2]) TFs are involved in stress responses in plants. However, their roles in abiotic stresses are still not well known in Malus plants. In the present study, MbNAC29 from Malus baccata was identified and characterized. Quantitative real-time PCR analysis revealed that the expression of MbNAC29 was induced by cold, high salinity, drought, and heat. The open reading frame (ORF) of MbNAC29 is 1122 bp, encodes 373 amino acids. Subcellular localization showed that the MbNAC29-GFP (green fluorescent protein) fusion protein was localized in the nucleus. Furthermore, MbNAC29 was highly expressed in new leaf and mature leaf. When MbNAC29 was introduced into Arabidopsis, it improved cold and high salinity tolerance in transgenic plants under low-temperature stress (− 4°C) and salt stress (200 mM NaCl). When MbNAC29 was introduced into Arabidopsis, it increased the survival rate of transgenic lines than wild type (WT) under cold and high-salinity stresses. In addition, overexpression of MbNAC29 in transgenic Arabidopsis increased the contents of chlorophyll and proline and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), while decreased the content of malondialdehyde (MDA). Therefore, these results suggest that MbNAC29 probably plays an important role in response to cold and salt stresses in Arabidopsis by enhancing scavenging capability of reactive oxygen species (ROS).

NAC（无顶端分生组织[NAM]，拟南芥转录激活因子[ATAF1 / 2]和杯状子叶[CUC2]）TFs参与植物的胁迫反应。然而，它们在非生物胁迫中的作用在苹果属植物中仍不为人所知。在本研究中，鉴定并鉴定了来自海棠的MbNAC29。实时定量PCR分析表明，MbNAC29的表达是受冷，高盐度，干旱和高温诱导的。MbNAC29的开放阅读框（ORF）为1122 bp，编码373个氨基酸。亚细胞定位表明MbNAC29-GFP（绿色荧光蛋白）融合蛋白定位在细胞核中。此外，MbNAC29在新叶和成熟叶中高表达。将MbNAC29引入拟南芥中后，它改善了转基因植物在低温胁迫（−4°C）和盐胁迫（200 mM NaCl）下的耐寒性和高盐分耐受性。当将MbNAC29引入拟南芥中时，在寒冷和高盐度胁迫下，它比野生型（WT）提高了转基因品系的存活率。此外，MbNAC29在转基因拟南芥中的过表达增加了叶绿素和脯氨酸的含量以及超氧化物歧化酶（SOD），过氧化物酶（POD）和过氧化氢酶（CAT）的活性，同时降低了丙二醛（MDA）的含量。因此，这些结果表明，MbNAC29可能通过增强活性氧（ROS）的清除能力而对拟南芥中的冷和盐胁迫起重要作用。