Tian Ping, Chen Daming, Wan Jiaqiong, Chen Chaoying, Zhao Ke, Zi Yinqiang, Liu Pu, Yang Chengquan, Zhang Hanyao, Liu Xiaozhen
Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming 650224, China.
Institute of Tropical Ecological Agriculture, Yunnan Province Academy of Agricultural Sciences, Chuxiong Yi Autonomous Prefecture 675000, China.
Plants (Basel). 2025 Aug 17;14(16):2560. doi: 10.3390/plants14162560.
Dehydration response element binding proteins (DREBs) have been identified as major regulators of cold acclimatization in many angiosperms. Cold stress is one of the primary abiotic stresses affecting kiwifruit growth and development. However, kiwifruit is currently one of the most widely consumed fruits worldwide because of its high nutritional value. 5-Aminolevulinic acid (5-ALA) is a nonprotein amino acid known for its distinct promotional effects on plant resistance, growth, and development. However, studies on the function of the kiwifruit DREB gene in alleviating low-temperature stress in its seedlings via exogenous 5-ALA have not been reported. Therefore, in this study, we performed a genome-wide identification of DREB gene family members in kiwifruit and analyzed the regulatory effects of exogenous 5-ALA on kiwifruit DREB genes under low-temperature stress. A total of 193 DREB genes were identified on 29 chromosomes. Phylogenetic analysis classified these genes into six subfamilies. Although there were some differences in cis-elements among subfamilies, all of them contained more biotic or abiotic stresses and hormone-related cis-acting elements. GO and KEGG enrichment analyses revealed that AcDREB plays an essential role in hormone signaling, metabolic processes, and the response to adverse stress. Under low-temperature stress, the application of exogenous 5-ALA inhibited the accumulation of APX and DHAR, promoted an increase in chlorophyll, and increased the accumulation of enzymes and substances such as 5-ALA, MDHAR, GR, ASA, GAH, and GSSH, thereby accelerating ROS scavenging and increasing the cold hardiness of kiwifruits. Functional analysis revealed that 46 differentially expressed DREB genes, especially those encoding , , and , which are involved in ethylene signaling and defense signaling, and, after the transcription of downstream target genes is activated, are involved in the regulation of low-temperature-stressed kiwifruits by exogenous 5-ALA, thus improving the cold tolerance of kiwifruits. Notably, , , and could serve as key genes for cold tolerance. This study is the first to investigate the function of AcDREB genes involved in the role of exogenous 5-ALA in regulating low-temperature stress, revealing the regulatory mechanism by which DREB is involved in the ability of exogenous 5-ALA to alleviate low-temperature stress.
脱水响应元件结合蛋白（DREB）已被确定为许多被子植物冷驯化的主要调节因子。低温胁迫是影响猕猴桃生长发育的主要非生物胁迫之一。然而，由于其高营养价值，猕猴桃目前是全球消费最广泛的水果之一。5-氨基乙酰丙酸（5-ALA）是一种非蛋白质氨基酸，以其对植物抗性、生长和发育具有独特的促进作用而闻名。然而，关于猕猴桃DREB基因通过外源5-ALA缓解其幼苗低温胁迫功能的研究尚未见报道。因此，在本研究中，我们对猕猴桃DREB基因家族成员进行了全基因组鉴定，并分析了外源5-ALA在低温胁迫下对猕猴桃DREB基因的调控作用。在29条染色体上共鉴定出193个DREB基因。系统发育分析将这些基因分为六个亚家族。虽然亚家族间顺式元件存在一些差异，但它们都含有更多与生物或非生物胁迫以及激素相关的顺式作用元件。基因本体（GO）和京都基因与基因组百科全书（KEGG）富集分析表明，AcDREB在激素信号传导、代谢过程以及对逆境胁迫的响应中起重要作用。在低温胁迫下，外源5-ALA的施用抑制了抗坏血酸过氧化物酶（APX）和脱氢抗坏血酸还原酶（DHAR）的积累，促进了叶绿素的增加，并增加了5-ALA、单脱氢抗坏血酸还原酶（MDHAR）、谷胱甘肽还原酶（GR）、抗坏血酸（ASA）、γ-谷氨酰半胱氨酸（GAH）和谷胱甘肽二硫化物（GSSH）等酶和物质的积累，从而加速活性氧（ROS）清除并提高猕猴桃的抗寒性。功能分析表明，46个差异表达的DREB基因，特别是那些编码参与乙烯信号传导和防御信号传导的基因，在激活下游靶基因转录后，参与外源5-ALA对低温胁迫下猕猴桃的调控，从而提高猕猴桃的耐寒性。值得注意的是，这些基因可作为耐寒性的关键基因。本研究首次探讨了AcDREB基因在参与外源5-ALA调节低温胁迫中的功能，揭示了DREB参与外源5-ALA缓解低温胁迫能力的调控机制。
