Wang Jingrong, Zhang Yong, Wang Junzheng, Khan Abid, Kang Zheng, Ma Yongbo, Zhang Jiarui, Dang Haoran, Li Tianlai, Hu Xiaohui
College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Key Laboratory of Protected Horticultural Engineering in Northwest, Ministry of Agriculture and Rural Affairs, Yangling, Shaanxi, 712100, China.
Hortic Res. 2024 Apr 4;11(6):uhae096. doi: 10.1093/hr/uhae096. eCollection 2024 Jun.
Cold stress significantly limits the yield and quality of tomato. Deciphering the key genes related to cold tolerance is important for selecting and breeding superior cold-tolerant varieties. γ-aminobutyric acid (GABA) responds to various types of stress by rapidly accumulating in plant. In this study, glutamic acid decarboxylase (GAD2) was a positive regulator to enhance cold stress tolerance of tomato. Overexpression of decreased the extent of cytoplasmic membrane damage and increased the endogenous GABA content, antioxidant enzyme activities, and reactive oxygen species (ROS) scavenging capacity in response to cold stress, whereas mutant plants showed the opposite trend. In addition, induced anthocyanin biosynthesis in response to cold stress by increasing the content of endogenous GABA. Further study revealed that expression was negatively regulated by the transcription factor SlTHM27. However, the transcript levels of were repressed under cold stress. Antioxidant enzyme activities, transcript levels, GABA and anthocyanin contents were significantly increased in mutant plants. Further, our study demonstrated that SlTHM27 decreases -promoted cold resistance in tomato by repressing transcription. Overall, our results showed that the SlTHM27- model regulates the cold tolerance in tomato by regulating GABA and anthocyanin.
冷胁迫显著限制番茄的产量和品质。解析与耐寒性相关的关键基因对于选育优良耐寒品种至关重要。γ-氨基丁酸（GABA）通过在植物中快速积累来响应各种类型的胁迫。在本研究中，谷氨酸脱羧酶（GAD2）是增强番茄耐冷胁迫的正向调节因子。GAD2过表达降低了细胞质膜损伤程度，并增加了响应冷胁迫时的内源GABA含量、抗氧化酶活性和活性氧（ROS）清除能力，而GAD2突变体植株表现出相反的趋势。此外，GAD2通过增加内源GABA含量来响应冷胁迫诱导花青素生物合成。进一步研究表明，GAD2的表达受到转录因子SlTHM27的负调控。然而，GAD2的转录水平在冷胁迫下受到抑制。GAD2突变体植株中的抗氧化酶活性、GAD2转录水平、GABA和花青素含量显著增加。此外，我们的研究表明，SlTHM27通过抑制GAD2转录降低了其促进的番茄抗冷性。总体而言，我们的结果表明，SlTHM27-GAD2模型通过调节GABA和花青素调控番茄的耐寒性。
