Topographic-Driven Micro-abiotic Stress Gradients Modulate Leaf-Level Physiological Efficiency and Secondary Metabolism Plasticity in Vitis vinifera cv. ‘Papazkarası’
APPLIED FRUIT SCIENCE, cilt.68, ss.1-16, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 68
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s10341-026-02020-x
- Dergi Adı: APPLIED FRUIT SCIENCE
- Derginin Tarandığı İndeksler: Food Science & Technology Abstracts, Scopus, Science Citation Index Expanded (SCI-EXPANDED), Environment Index
- Sayfa Sayıları: ss.1-16
- Çanakkale Onsekiz Mart Üniversitesi Adresli: Evet
Özet
Fine-scale topographic heterogeneity may generate contrasting microenvironments within rainfed vineyards, but it remains unclear whether leaf gas exchange and secondary metabolism respond with similar sensitivity to these natural gradients. Topographic micro-abiotic stress gradients were evaluated for their effects on leaf-level physiological efficiency and secondary metabolism plasticity in the indigenous red grape cultivar ‘Papazkarası’ (Vitis vinifera L.) grafted on 5BB rootstock. The study was conducted during the 2024 growing season in a non-irrigated vineyard along a uniform 10.17% slope divided into lower (LS), middle (MS), and upper (US) zones. Net photosynthesis (A), stomatal conductance gs, and intrinsic (WUEi = A/gs) and instantaneous (WUEins = A/E) water-use efficiency were measured 11 times. Pooled leaf samples were analyzed for photosynthetic pigments, abscisic acid, proline, total phenolics, tannins, antioxidant capacity, and individual phenolic compounds. Gas-exchange traits varied among dates but showed little spatial differentiation, and net photosynthesis remained similar across slope positions (10.29–10.59 μmol CO2 m−2 s−1). By contrast, total phenolics, tannins, the chlorophyll a/b ratio, and most individual phenolics increased toward the upper slope, whereas chlorophyll b and total chlorophyll declined. Abscisic acid, proline, and antioxidant capacity showed weaker or inconsistent responses. Multivariate analyses clearly separated upper-slope samples through their phenolic profiles. These results indicate that cv. ‘Papazkarası’ maintains stable photosynthetic performance while up-regulating protective phenolic pathways under conditions potentially associated with lower soil water availability. The observed physiological stability coupled with biochemical plasticity highlights the cultivar’s adaptive capacity in non-irrigated Mediterranean-type vineyards of Thrace and suggests that upper-slope sites may enhance leaf phenolic potential under projected warming and drying trends.