2026/07/15 by Toon Suzuki, M. Takayama, Hiroshi Ezura · 1 voice
Agricultural and Biological Sciences · #GABA and Rice Research #Postharvest Quality and Shelf Life Management #Plant Stress Responses and Tolerance
paper · doi:10.1002/pei3.70187
openalex publication_date 2026/07/15 · openalex created_date 2026/07/17 · openalex updated_date 2026/07/23
ABSTRACT While exogenous γ‐aminobutyric acid (GABA) enhances plant stress tolerance, fruit responses to increased endogenous GABA biosynthesis remain unclear. Although high‐GABA traits mitigate productivity loss in cherry tomatoes under salt stress, salinity responses differ among cultivars, and whether this occurs in medium‐sized tomatoes remains unknown. We tested whether endogenous GABA enrichment maintains production and promotes dry matter and GABA accumulation under salt stress. The medium‐sized tomato ‘Esprosso’ (ER), and its genome‐edited high‐GABA line (ERHG) were grown under control and salt stress conditions. Under salt stress, fruit fresh weight decreased by 43.4% in ER and 31.5% in ERHG, whereas fruit number per plant increased by 33.3% in ER and 71.1% in ERHG. Due to this compensatory increase, mean yield changes (+2.6% in ER and +11.1% in ERHG) were not statistically significant. Dry matter content increased by 0.6 percentage points (pp) in ER and 1.5 pp. in ERHG, showing a significant genotype × salt stress interaction. Salt stress elevated GABA concentration by 64.5% in ER and 74.4% in ERHG (from 141.5 to 246.8 mg 100 g −1 FW), increasing per‐fruit GABA content by 22.8% in ERHG. Total soluble solids (TSS) and ascorbic acid increased under salt stress in both genotypes, indicating the high‐GABA trait did not reduce TSS, whereas proline showed a genotype‐dependent response. These results suggest that enhanced endogenous GABA biosynthesis modifies fruit responses to salt stress by promoting GABA and dry matter accumulation and altering osmolyte‐related metabolism without reducing TSS, potentially contributing to high‐value tomato production under controlled salinity.