ATAF样NAC转录因子是应激信号传导的真正调节因子。然而,它们的过表达通常通过激活ABA超敏反应来发挥生长迟缓,叶绿体降解,或者碳饥饿。为了提高对多重压力的耐受性,符合增长可持续性,我们检查了两个ATAF直系同源物,VuNAC1和VuNAC2,从耐旱的cow豆基因型分离,对压力和生长信号进行协调调节。这些基因是由脱水诱导的,NaCl,聚乙二醇,热,冷,ABA,和光。启动子元件和调控网络的分析证实了昼夜节律的整合,荷尔蒙,压力,发展,和营养信号,VuNAC1/2是连接生长和应激反应的中心转录开关。拟南芥中的组成型基因过表达导致胚胎的改善,玫瑰花结,和花序生长,在最佳和有限的营养下,与光合活性和气孔密度增加有关。转基因幼苗表现出对脱水的耐受性,盐度,铝,镉,和H2O2毒性,除了ABA介导的种子休眠和超敏反应。土壤种植的植物通过积累胁迫保护剂来维持水分状态和膜完整性,从而在严重的干旱和高盐度下幸存下来。如脯氨酸,谷胱甘肽,和抗坏血酸。与其他物种的直系同源物不同,VuNAC1/2通过调节光合控制和营养平衡,赋予了对多种非生物胁迫的耐受性,同时改善了生长属性。表明生长是应激耐受性和恢复的重要组成部分。这种独特的应激反应转录因子,这也赋予了光合增益,可以是可持续的生物技术工具,用于开发耐胁迫的作物,并将改善的生长转化为产量,而无需进行意外的权衡。
ATAF-like NAC transcription factors are bonafide regulators of stress-signaling. However, their overexpression often exerts growth-retardation by activating ABA-hypersensitivity, chloroplast-degradation, or carbon-starvation. To improve tolerance to multiple stress complying with growth sustainability, we examined two ATAF orthologs, VuNAC1 and VuNAC2, isolated from a drought-hardy cowpea genotype, for a harmonized regulation of stress and growth signaling. The genes were induced by dehydration, NaCl, polyethylene glycol, heat, cold, ABA, and light. Analysis of the promoter-elements and regulatory network corroborated the integration of circadian, hormonal, stress, developmental, and nutrition signals, being VuNAC1/2 the central transcriptional-switch interfacing growth and stress responses. The constitutive gene overexpression in Arabidopsis resulted in an improved embryonic, rosette, and inflorescence growth, under optimum as well as limiting nutrition, in association with increased photosynthetic activity and stomatal-density. The transgenic seedlings manifested tolerance to dehydration, salinity, aluminum, cadmium, and H2O2 toxicity, in addition to ABA-mediated seed dormancy and hypersensitivity. The soil-grown plants survived severe drought and hypersalinity by maintaining the water-status and membrane integrity through the accumulation of stress protectants, such as proline, glutathione, and ascorbate. Unlike their orthologs from other species, VuNAC1/2 conferred tolerance to multiple abiotic stresses in line with improved growth attributes via regulation of photosynthetic controls and nutritional balance, suggesting growth being a crucial component of stress-tolerance and recovery. Such unique stress-responsive transcription factors, which also confer photosynthetic gain, could be sustainable biotechnological tools for developing stress-tolerant crops and translating the improved growth into yield without unintended trade-offs.