The AlkB Homolog SlALKBH10B Negatively Affects Drought and Salt Tolerance in Solanum lycopersicum

Abstract

ALKBH proteins, the homologs of Escherichia coli AlkB dioxygenase, constitute a single-protein repair system that safeguards cellular DNA and RNA against the harmful effects of alkylating agents. ALKBH10B, the first discovered N6-methyladenosine (m6A) demethylase in Arabidopsis (Arabidopsis thaliana), has been shown to regulate plant growth, development, and stress responses. However, until now, the functional role of the plant ALKBH10B has solely been reported in arabidopsis, cotton, and poplar, leaving its functional implications in other plant species shrouded in mystery. In this study, we identified the AlkB homolog SlALKBH10B in tomato (Solanum lycopersicum) through phylogenetic and gene expression analyses. SlALKBH10B exhibited a wide range of expression patterns and was induced by exogenous abscisic acid (ABA) and abiotic stresses. By employing CRISPR/Cas9 gene editing techniques to knock out SlALKBH10B, we observed an increased sensitivity of mutants to ABA treatment and upregulation of gene expression related to ABA synthesis and response. Furthermore, the Slalkbh10b mutants displayed an enhanced tolerance to drought and salt stress, characterized by higher water retention, accumulation of photosynthetic products, proline accumulation, and lower levels of reactive oxygen species and cellular damage. Collectively, these findings provide insights into the negative impact of SlALKBH10B on drought and salt tolerance in tomato plant, expanding our understanding of the biological functionality of SlALKBH10B.

The YABBY Transcription Factor, SlYABBY2a, Positively Regulates Fruit Septum Development and Ripening in Tomatoes

“…Excitation wavelengths for GFP and RFP were set at 488 nm and 563 nm, respectively, and emission wavelengths for GFP and RFP were set at 507 nm and 582 nm, respectively. The cultivation of Agrobacterium and the preparation of the re-suspension solution were performed as previously described [75].…”

Detection, distribution, and functions of RNA N6-methyladenosine (m6A) in plant development and environmental signal responses

“…Silencing of the GhALKBH10 gene in cotton can increase the m 6 A modification level, enhance the antioxidant capacity, and reduce the Na + concentration in the cytoplasm, thereby improving the plant’s tolerance to salinity ( Cui et al., 2022 ). SlALKBH10B negatively regulates cell damage in salt stress, thereby rendering plants salt-intolerant ( Shen et al., 2023a ).…”

“…Of these, AtALKBH10B, AtALKBH6, and AtALKBH9C have been identified as possessing demethylation functions ( Duan et al., 2017 ; Huong et al., 2020 ; Amara et al., 2022 ). Furthermore, CsALKBH4 in tea, CfALKBH5 in Catalpa fargesii , SlALKBH2 and SlALKBH10B in tomato, GhALKBH10 and GhALKBH10B in cotton, OsALKBH9 in rice, PagALKBH9B and PagALKBH10B in Populus , LbALKBH10 in wolfberry, and HrALKBH10B, HrALKBH10C, and HrALKBH10D in sea buckthorn have also been identified as having demethylation functions ( Zhou et al., 2019 ; Zhang et al., 2021a ; Cui et al., 2022 ; Zhao et al., 2022 , 2023 ; Zhu et al., 2023 ; Li et al., 2023a ; Shen et al., 2023a ; Zhang et al., 2023c ; Tang et al., 2024 ). Given the numerous AlkB family homologs in plants and the diverse functions of the AlkB family proteins, the identification of more m 6 A demethylases requires extensive and detailed research.…”