20.500.12556/DiRROS-24837 Comparative metabolic fingerprinting of olive (Olea europaea L.) cultivars under boron foliar fertilisation Olive (Olea europaea L.) cultivars often exhibit genotype-specific responses to micronutrient management. In this study, we investigated the metabolic leaf fingerprinting of three cultivars ‘Rošinjola’, ‘Leccino’, and ‘Istarska bjelica’ at two sampling periods (SP-I = 64 days after treatment (DAT) and SP-II = 118 DAT), following boron foliar fertilisation (+B = 41.62 mM B; −B = 0 mM B) applied 50 days after anthesis. To our knowledge, this is the first study to provide such a detailed evaluation of boron-induced shifts in phenolic metabolism in olive leaves. At harvest (SP-II), all three cultivars showed higher concentrations of total identified phenolic compounds in +B plants compared with the −B controls. Notably, the concentration of verbascoside at harvest was higher in +B plants of ‘Istarska bjelica’ and ‘Leccino’, but not in ‘Rošinjola’. Oleuropein content increased in +B plants at harvest to a level higher than 4870 mg/100 g DW, irrespective of cultivar. Conversely, apigenin-7-glucoside declined from SP-I to SP-II in ‘Leccino’ regardless of treatment, whereas in ‘Istarska bjelica’, this decrease occurred only in control plants, with boron preventing the seasonal decline. These findings confirm the prolonged effect of boron foliar fertilisation on phenolic metabolism in olive leaves and highlight cultivar-specific differences in metabolic responses. Further research is needed to clarify how these metabolic shifts relate to primary plant metabolism and how they influence olive oil quality traits among cultivars grown under Croatian conditions. plant metabolism olive leaves oleuropein Istrian cultivars metabolizem rastlin oljčni listi istrske sorte true false true MDPI Švica Angleški jezik Slovenski jezik © 2025 by the authors. Neznano 2025-12-22 10:39:59 2025-12-22 10:39:59 2025-12-23 03:59:12 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Soavtorica iz Slovenije: Paula Pongrac; Opis vira z dne 19. 12. 2025; str. 1-16 iss. 12, [article no.] 1521 Vol. 11 Dec. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2025-11-11 2025-12-12 2025-12-15 634.1/.7 2311-7524 10.3390/horticulturae11121521 262295299 https://www.mdpi.com/2311-7524/11/12/1521 1 30f6ee44-df1a-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=37155 RAZ_Zurga_Paula_2025.pdf RAZ_Zurga_Paula_2025.pdf 1 4F0D261BC16D702748DF091D92EAA9C1 450b6f28b1c833804d4af8dbfb6098ade0457dc7fe0394d9d147e54de2e4fd7e 696c2c4e-df1a-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=37156 Institut Jožef Stefan 0 0 0