主要结论
“Hamlin”柑橘中VvmybA1转录因子的过度表达通过增加花青素积累来增强耐冷性。这导致了活性氧清除的改善、基因表达的改变和气孔调节,凸显了花青素在柑橘冷驯化中的重要作用。
抽象的
冷胁迫是柑橘种植的重大威胁,影响树木的健康和生产力。花青素以其作为色素的作用而闻名,并已成为植物防御环境压力源机制的关键介质。本研究调查了葡萄 ( Vitis vinifera ) VvmybA1转录因子调控花青素过度表达以增强柑橘树冷胁迫耐受性的潜力。过度表达VvmybA1的转基因“Hamlin”柑橘树与对照野生型树一起在 4°C 下暴露于 30 天的冷胁迫期。我们的研究结果表明,花青素积累显着影响叶绿素含量及其荧光参数,影响叶片对冷胁迫的反应。此外,我们还记录了转基因叶子中增强的ROS清除能力以及关键转录因子和抗氧化相关基因的独特表达模式。此外, VvmybA1过表达通过调节ABA生物合成影响气孔孔径调节,导致转基因树和野生型树在冷胁迫下气孔开放的反应不同。转基因树表现出过氧化氢水平降低、类黄酮增强、自由基清除活性和植物激素谱改变。这些发现强调了VvmybA1介导的花青素积累在增强耐冷性方面的作用。目前的研究还强调了花青素过度表达通过清除植物组织中的ROS作为冷驯化过程的关键调节剂的潜力。
"点击查看英文标题和摘要"
Physiological and molecular responses of ‘Hamlin’ sweet orange trees expressing the VvmybA1 gene under cold stress conditions
Main conclusion
Overexpression of VvmybA1 transcription factor in ‘Hamlin’ citrus enhances cold tolerance by increasing anthocyanin accumulation. This results in improved ROS scavenging, altered gene expression, and stomatal regulation, highlighting anthocyanins’ essential role in citrus cold acclimation.
Abstract
Cold stress is a significant threat to citrus cultivation, impacting tree health and productivity. Anthocyanins are known for their role as pigments and have emerged as key mediators of plant defense mechanisms against environmental stressors. This study investigated the potential of anthocyanin overexpression regulated by grape (Vitis vinifera) VvmybA1 transcription factor to enhance cold stress tolerance in citrus trees. Transgenic 'Hamlin' citrus trees overexpressing VvmybA1 were exposed to a 30-day cold stress period at 4 °C along with the control wild-type trees. Our findings reveal that anthocyanin accumulation significantly influences chlorophyll content and their fluorescence parameters, affecting leaf responses to cold stress. Additionally, we recorded enhanced ROS scavenging capacity and distinct expression patterns of key transcription factors and antioxidant-related genes in the transgenic leaves. Furthermore, VvmybA1 overexpression affected stomatal aperture regulation by moderating ABA biosynthesis, resulting in differential responses in a stomatal opening between transgenic and wild-type trees under cold stress. Transgenic trees exhibited reduced hydrogen peroxide levels, enhanced flavonoids, radical scavenging activity, and altered phytohormonal profiles. These findings highlighted the role of VvmybA1-mediated anthocyanin accumulation in enhancing cold tolerance. The current study also underlines the potential of anthocyanin overexpression as a critical regulator of the cold acclimation process by scavenging ROS in plant tissues.