Genome-Wide Identification and Expression Profiling of Glutamate Decarboxylase (LuGAD) Genes in Flax (Linum usitatissimum L.): Insights into Their Role in Drought Stress Tolerance and GABA-Mediated Regulation
JOURNAL OF PLANT GROWTH REGULATION, cilt.9, ss.1-24, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 9
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s00344-026-12452-0
- Dergi Adı: JOURNAL OF PLANT GROWTH REGULATION
- Derginin Tarandığı İndeksler: Natural Science Collection (ProQuest), Biological Science Database (ProQuest), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest), Scopus, Science Citation Index Expanded (SCI-EXPANDED), BIOSIS, Chemical Abstracts Core, CAB Abstracts
- Sayfa Sayıları: ss.1-24
- Çanakkale Onsekiz Mart Üniversitesi Adresli: Evet
Özet
Gamma-Aminobutyric Acid (GABA), a non-proteinogenic amino acid ubiquitous in living organisms, contributes significantly to plant physiology by acting as both a metabolic intermediate and a signaling compound. Four the Glutamate Decarboxylase (LuGAD) genes in the flax genome were identified, and were localized on chromosomes 1, 2 and 13. The LuGAD genes possess varying numbers of exons, and the cis-acting regulatory element analysis revealed that these genes contain regulatory regions associated with various abiotic stresses, hormone responses, and tissue-specific expression profiles. Phylogenetic analysis revealed that the LuGAD genes cluster within Class I and share a close evolutionary relationship with Arabidopsis thaliana GAD1 and GAD2 genes. All LuGAD proteins contain highly conserved PLP_deC domain, characteristic of GAD enzymes. Protein–protein interaction predictions indicated that LuGAD proteins potentially interact with key metabolic and stress-related partners, including GABA-T, P5CS, P5CDH, and PI-4Kβ1. RNA-seq data revealed that LuGAD genes exhibit dynamic expression levels in various tissues and at different developmental stages in flax, showing that especially LuGAD1, LuGAD2, and LuGAD3 are expressed at low levels in leaves. The RT-qPCR results showed that the expression levels of LuGAD genes varied significantly depending on plant variety, duration and severity of drought stress and exogenous GABA treatment. Moreover, LuGAD2 was not expressed in leaf tissues under any condition. This study presents the first comprehensive genome-wide characterization of the LuGAD gene family in flax, highlighting their limited expression in response to drought stress in leaves. The findings not only elucidate the potential roles of the LuGAD gene family in flax and the molecular responses associated with abiotic stresses but also provide a valuable basis for future research on the functional characterization of this gene family.