Ningxia Key Laboratory for Agrobiotechnology, Agricultural Bio-Technology Center, Ningxia Academy of Agriculture and Forestry Science, 590 Huanghe East Road, Yinchuan, Ningxia Hui Nationality Autonomous Region, 750002, China.
School of Life Sciences, Ningxia University, 489 Helanshan West Road, Yinchuan, Ningxia Hui Nationality Autonomous Region, 750021, China.
Plant Physiol Biochem. 2020 Jun;151:535-544. doi: 10.1016/j.plaphy.2020.04.008. Epub 2020 Apr 12.
NAC transcription factors play a pivotal role in plant growth, development and response to abiotic stress. However, their biological functions in desert trees are largely unknown. In this work, the NAC transcription factor HaNAC1 from Haloxylon ammodendron, a typical wooden plant normally grown in desert, was isolated, and its possible role in plant growth and resistance to drought stress was investigated. HaNAC1 encodes an ATAF subfamily transcription factor containing one NAC domain with five conserved regions. Quantitative real time PCR analyses revealed that HaNAC1 was ubiquitously expressed in various tissues and organs such as roots, stems, leaves and seeds, with a predominant expression in stems. Further studies demonstrated that expression of HaNAC1 was significantly induced by osmotic stress in Haloxylon ammodendron seedlings, and subcellular localization analysis indicated that GFP-HaNAC1 fusion protein was localized to the nucleus in Arabidopsis leaf protoplast. Ectopic expression of HaNAC1 led to promoted growth and drought tolerance in transgenic Arabidopsis, accompanied with up-regulated expression of stress-inducible marker genes, and increased accumulation of proline, IAA and ABA under both normal and drought stress conditions. In addition, co-immunoprecipitation and Bi-molecular fluorescence complementation assays illustrated that HaNAC1 directly interacted with AtNAC32. All these results suggest that HaNAC1 is involved in both the growth and drought resistance of Haloxylon ammodendron, and could be used as a promising candidate gene for the breeding of crops with augmented tolerance to drought stress.
NAC 转录因子在植物的生长、发育和对非生物胁迫的响应中起着关键作用。然而，它们在沙漠树木中的生物学功能在很大程度上是未知的。在这项工作中，从典型的沙漠木本植物梭梭中分离出 NAC 转录因子 HaNAC1，并研究了其在植物生长和抗旱性中的可能作用。HaNAC1 编码一个 ATAF 亚家族转录因子，包含一个具有五个保守区域的 NAC 结构域。定量实时 PCR 分析显示，HaNAC1 在各种组织和器官中广泛表达，如根、茎、叶和种子，在茎中表达最为丰富。进一步的研究表明，HaNAC1 在梭梭幼苗中受到渗透胁迫的显著诱导，亚细胞定位分析表明 GFP-HaNAC1 融合蛋白定位于拟南芥叶片原生质体的细胞核中。HaNAC1 的异位表达导致转基因拟南芥的生长和耐旱性得到促进，伴随着应激诱导标记基因的上调表达，以及在正常和干旱胁迫条件下脯氨酸、IAA 和 ABA 的积累增加。此外，免疫共沉淀和双分子荧光互补测定表明 HaNAC1 与 AtNAC32 直接相互作用。所有这些结果表明，HaNAC1 参与了梭梭的生长和抗旱性，并且可以作为培育对干旱胁迫具有增强耐受性的作物的有前途的候选基因。
