Unraveling grapevine resilience to water and nutrient limitations

Abstract

Water and nutrient availability significantly impact crop yield, thus the application of sustainable strategies towards efficient water use and nutrient absorption by plants is needed. Moreover, it has been demonstrated that some microorganisms can promote plant fitness and tolerance to abiotic stresses. The aim of the present study is to assess the physiological and biochemical responses of two grapevine cultivars under different edaphic conditions, specifically water deficit and nutrient limitation, and the effect of arbuscular mycorrhizal fungi (AMF) application.

Two-year-old Cabernet Sauvignon and Grenache plants grafted on S.O.4. rootstocks were sown in 20-L soil pots under semi-environmental conditions. Plants were either maintained well-watered or subjected to a controlled water deficit irrigation and treated with different nitrogen (N) and potassium (K) fertilization doses. Grapevine resilience to water deficit was also assessed in a second trial in combination with AMF. During two growing seasons, leaves and roots were collected for physiological and molecular measurements. Roots from the second trial were collected for ionomic, metabolomic, and transcriptomic analyses, and the level of mycorrhization will be evaluated microscopically, whereas soil samples will be submitted for microbiome sequencing analyses. Water deficit caused a significant reduction in plant growth and several physiological parameters, such as transpiration rate and stem water potential. Multi-elemental data from ICP-OES and CHN-IRMS at flowering stage showed that plants mainly separated in response to irrigation treatment. Conversely, the nutrient composition at the maturity stage was strongly influenced by N fertilization. Finally, the effect of the mycorrhizal treatment has been shown to be more pronounced under water deficit conditions. Multi-omics data will be integrated with information obtained from µ-XRF analyses that provide spatial resolution of the elemental distribution of leaves and roots. The results obtained will improve the comprehension of the mechanisms involved in the signaling network of the interplay among water and nutrient acquisition.

Acknowledgements

Work supported by Prin 2022PNRR, M4C2 Inv.1.1 Finanziato dall’Unione Europea – Next generation EU, Spatial characterization of molecular responses to water deficit and nitrogen limitation in grapevine roots – P20222XJKY, CUP G53D23007660001; Agritech National Research Center that received funding from the European Union.

Next-GenerationEU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR) – MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4 – D.D. 1032 17/06/2022, CN00000022).