A synthetic cytokinin primes photosynthetic and growth response in grapevine under ion-independent salinity stress
Giuseppe Montanaro, Nunzio Briglia, Loredana Lopez, Davide Amato, Francesco Panara, Angelo Petrozza, Francesco Cellini, Vitale Nuzzo
Abstract
Aiding optimal plant–environment interaction would favor plant resilience against environmental constrains including salt stress. We test the hypothesis that 6-Benzylaminopurine (BAP) primes grapevine’s salt tolerance in vines (Vitis vinifera) received salt water (NaCl 100 mM) through the modulation of gene expression of BAP (AHK4, AHP1) and salt-stress (CAT, APX) inducible genes and morpho-physiological traits. A subgroup of vines had previously (48 h) been primed with BAP (80 mg/L) before salt stress. The gene expressions were 30% (CAT) and 56% (APX) lower in primed salt-stressed vines than that in un-primed. Salt treatment did not increase leaf Na+ but it lowered stomatal conductance (gs), photosynthesis (A), stem water potential (less negative) and photosystem-II efficiency (Fv/Fm). Chlorophyll-a concentrations were 30% higher in BAP-primed compared to un-primed. Adverse effects of salt were significantly reduced, maintaining high A/gs, Fv/Fm and growth. After the relief of the stress, the BAP primed vines had a fast recovery.