biostudies-literatureZhu ZJiujiang Xun Cheng TalentNational Natural Science Foundation of China1376https://www.ebi.ac.uk/biostudies/studies/S-EPMC12522792biostudies-literatureUnknown25(1)<h4>Background</h4>Trihelix factors play important roles in improving plant resistance to abiotic stress, however, the role of SIP1 subfamily contributing to cold tolerance was rarely reported in tomatoes. Here, we isolated a cold-repressed gene, SlGT-33, from the tomato and found it vital biological function in morphological development and adaptation to prolonged chilling stress.<h4>Results</h4>SlGT-33 belonged to SIP1 clade and was localized to cell nucleus. SlGT-33 was specifically expressed in mature leaves and stems, induced by ABA and dehydration, and repressed by GA and low temperature. Overexpression of SlGT-33 suppressed the chlorophyll synthesis but promoted fruits set than control under prolonged cold conditions. Transcriptome and metabolome analysis demonstrated that SlGT-33 OBMC plant biologyA SIP1 gene of Trihelix family, SlGT-33, promotes chilling tolerance and fruits set under prolonged cold stress in tomatoes.PMC1252279232460679202432160711Liu XLi ZFu SYu MZhu ZBai JZhong ZYe JCui BfalseA SIP1 gene of Trihelix family, SlGT-33, promotes chilling tolerance and fruits set under prolonged cold stress in tomatoes.<h4>Background</h4>Trihelix factors play important roles in improving plant resistance to abiotic stress, however, the role of SIP1 subfamily contributing to cold tolerance was rarely reported in tomatoes. Here, we isolated a cold-repressed gene, SlGT-33, from the tomato and found it vital biological function in morphological development and adaptation to prolonged chilling stress.<h4>Results</h4>SlGT-33 belonged to SIP1 clade and was localized to cell nucleus. SlGT-33 was specifically expressed in mature leaves and stems, induced by ABA and dehydration, and repressed by GA and low temperature. Overexpression of SlGT-33 suppressed the chlorophyll synthesis but promoted fruits set than control under prolonged cold conditions. Transcriptome and metabolome analysis demonstrated that SlGT-33 O2025-01-01T00:00:00Z2025 Oct2026-06-04T11:48:07.427Z2026-05-08T03:11:07.274ZS-EPMC125227924108790510.1186/s12870-025-07385-x