Abscisic acid and proline are not equivalent markers for heat, drought and combined stress in grapevines

Background and Aims Viticulture will be particularly affected by increasing drought heat waves in the future. It is of interest to find traits that indicate stress before symptoms become apparent. We investigated whether commonly used traits, proline abscisic acid (ABA) biosynthesis, are suitable markers for heat, or combined gene expression key enzymes ABA biosynthesis regulated grapevine leaves under these conditions. Methods Results Plant growth gas exchange were measured evaluate plant reactions increased temperature water deficit. Proline concentration leaf material was measured, respectively, photometrically with GC/MS. Gene analysis NCED1, NCED2 P5CS done real-time quantitative reverse transcription-polymerase chain reaction. Drought had a stronger effect on growth, exchange, proline, than stress. An interaction between observed biosynthesis. Conclusions good The marker might NCED1 stress, whereas not suitable. Significance Study These results provide insight into response grapevines show suitability as markers.