SlGAD2 is the target of SlTHM27, positively regulates cold tolerance by mediating anthocyanin biosynthesis in tomato

Abstract

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 SlGAD2 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 Slgad2 mutant plants showed the opposite trend. In addition, SlGAD2 induced anthocyanin biosynthesis in response to cold stress by increasing the content of endogenous GABA. Further study revealed that SlGAD2 expression was negatively regulated by the transcription factor SlTHM27. However, the transcript levels of SlTHM27 were repressed under cold stress. Antioxidant enzyme activities, SlGAD2 transcript levels, GABA and anthocyanin contents were significantly increased in Slthm27 mutant plants. Further, our study demonstrated that SlTHM27 decreases SlGAD2 -promoted cold resistance in tomato by repressing SlGAD2 transcription. Overall, our results showed that the SlTHM27- SlGAD2 model regulates the cold tolerance in tomato by regulating GABA and anthocyanin.

Acknowledgements

This work was supported by Scientific and Technological Innovative Research Team of Shaanxi Province (2021TD-34), China Agriculture Research System (CARS-23-D06), and the National College Student Innovation and Entrepreneurship Training Program (202210712083 and X202310712703). The authors thank the Horticulture Science Research Center at College of Horticulture, Northwest A&F University for their technical support in this work. The authors are grateful to Jing Zhang (Horticulture Science Research Center, Northwest A&F University, Yangling, China) for providing professional technical assistance with LC-MS analysis.

Author contributions

X.H., T.L., J.W., and Y.Z. conceived and designed the experiments. J.W. and X.H. wrote the paper. J.W. and Y.Z. performed the experiments. J.W., A.K., Z.K., Y.M., J.Z., and H.D. provided advice related to the research. All authors read and approved the manuscript for submission.

Data availability

All relevant data for this study are provided in this article and its supplements.

Conflict of interest statement

The authors declare no competing interests.

Supplementary data

Supplementary data is available at Horticulture Research online.

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