Center za raziskave vina

N4-0158 ARRS

Metabolna prilagodljivost rastlin na vodni stres

Projekt preučuje metabolni odziv vinske trte (Vitis vinifera L.) na pomanjkanje vode v dveh podnebno različnih okoljih (hladnem in toplem) z namenom izboljšanja razumevanja interaktivnih učinkov pomanjkanja vode in podnebnih dejavnikov na fiziologijo rastlin.

Osrednja hipoteza projekta je, da imajo podnebne spremenljivke (kot sta npr. svetloba in temperatura) ključno vlogo pri odzivu rastline na sušo, zlasti na njeno metabolno reprogramiranje. Posledično lahko isti genotip izrazi drugačen fenotip v primeru suše v različnih podnebnih razmerah (t.i. plastičnost). Fenotipska plastičnost je opredeljena kot količina, za katero se izražanje posameznih značilnosti genotipa spremeni v različnih okoljih in vinska trta se je izkazala za precej fenotipsko plastično. Kljub temu pa plastičnost odziva vinske trte na abiotski stres, kot je suša, še ni bila podrobneje raziskana.

Obseg oslabitve med razpoložljivostjo/dostopnostjo vode in potrebo po vodi - določa stopnjo pomanjkanja vode v sistemu. Do danes je bilo opravljenih zelo malo raziskav v namenom razumevanja ali podobni stopnji vodnega stresa v dveh različnih okoljih (npr. hladnem in toplem) sledi podoben metabolni odziv rastline. Ta projekt je zasnovan za zapolnitev te vrzeli v znanju in sicer z raziskovanjem metabolne plastičnosti vinske trte v primeru suše v različnih podnebnih razmerah. Rezultati bodo omogočili boljše modeliranje mehanizmov prilagajanja vinske trte različnim okoljem in možnim scenarijem podnebnih sprememb.

Posebni cilji projekta so:

  1. Raziskati vpliv na biosintezo primarnih in sekundarnih metabolitov v listih vinske trte in grozdnih jagodah v primeru dolgotrajnega in kratkotrajnega vodnega stresa v toplem oz. v hladnem podnebju.
  2. Določiti možne biomarkerje vodnega stresa v listih vinske trte in grozdnih jagodah (npr. hlapne spojine v listih GLV, aminokisline, manj pogosti sladkorji, lipidi…) in njihovo povezavo z okoljem (klimo).
  3. Ugotoviti, kakšni so prilagoditveni mehanizmi rastlin na vodni stres, ki so jih sprejele rastline v toplem ali hladnem podnebju v smislu fizioloških parametrov, kot so osmoregulacija listov, zapiranje listnih rež, zmanjšanje listne površine (obseg odpadanja listov).
  4. Ugotoviti, ali/katere morfološke/anatomske lastnosti so različne zaradi razvoja rastline v dveh različnih klimatih in v kolikšni meri te lastnosti vplivajo na rastlinski odziv (npr. zgradba ksilema, površina listov, skupna biomasa itd.).

Predlagani pristop nam bo omogočil odgovoriti na odprta vprašanja, ki so ključna za oceno odpornosti vinske trte na sušo v različnih podnebnih scenarijih, npr: Kakšna je največja intenzivnost vodnega stresa, preden se opazijo škodljivi učinki za pridelavo vinske trte v hladnem ali toplem podnebju? Kaj se v primeru suše zgodi s ključnimi metaboliti jagod, kot so malat, antocianini ali aromatične spojine, v podnebju s povprečno najvišjo poletno temperaturo 30 °C (Vipava) v primerjavi s hladnejšim podnebjem z maksimumom 25 °C (Tulln)? Ali je metabolni odziv na pomanjkanje vode v dveh izrazito različnih podnebjih specifičen za organe (grozdne jagode in listi)?

Pričakovani rezultati:

i) Projekt bo zagotovil boljše razumevanje a) fiziologije prilagoditve vinske trte na okoljski stres in njegove točke nepovratnosti ter b) reprogramiranja primarne in sekundarne presnove grozdnih jagod in listov kot posledice pomanjkanja vode, podnebja ali obojega v dobro opredeljenih delno kontroliranih ali popolnoma kontroliranih okoljih;

ii) Izpostavljeni bodo novi biomarkerji iz osrednjega C-N metabolizma (nižji sladkorji) ali sekundarne presnove (polifenoli ali GLV), ki jih uravnava omejena razpoložljivost vode, podnebje ali kombinacija obojega;

iii) Pričakujemo, da bodo identificirane molekule, ki so močno vpletene v odziv rastlin na razmere pomanjkanja vode, neodvisno in v povezavi z okoljem (klimo) v listih in grozdju vinske trte; do danes še vedno slabo raziskana tema. Predvidevamo, da bi lahko manj pomembni sladkorji, GLV ali določeni polifenoli, pa tudi glutation in terpenoidi igrali pomembno vlogo.

Pričakovani rezultati projekta so nadgradnja obstoječega znanja o interakciji genotip x okolje (fenotip) s poudarkom na odzivu na sušo, kar zagotavlja dobro podlago za nadaljnje preučevanje interakcije abiotskih stresorjev, možnih posledic podnebnih sprememb in splošnega boljšega modeliranja metabolne regulacije vinske trte v suši.

Metode:

Za doseganje ciljev je projekt razdeljen na tri glavne poskusne sklope:

1) Poskusi s pomanjkanjem vode (vodni stres) na dveh različnih lokacijah (Tulln, Avstrija in Vipava, Slovenija), ob uporabi istega genotipa, ki je bil predhodno gojen 2 leti na eni sami lokaciji (Avstrija), z namenom, da se zagotovi homogenost med rastlinami (slika 3).

2) Poskusi s pomanjkanjem vode, izvedeni v popolnoma nadzorovanih pogojih v rastlinjaku (slika 4a).

3) Fenotipizacija posameznega genotipa, posajenega in gojenega na dveh različnih lokacijah (Tulln, Avstrija in Vipava, Slovenija) od leta 1, za karakterizacijo fenotipske plastičnosti vinske trte

Exploring grapevine metabolic plasticity under drough

The project will study the grapevine (Vitis vinifera L.) metabolic response to water deficit in two climatically different environments (cool and warm) with the aim to shed some light on the interactive effects of water stress and climate on the plant physiology.

The central hypothesis of the project is that climatic variables (such as light and temperature) play a crucial role influencing the plant response to drought, in particular its metabolic reprograming. Consequently, the same genotype would exhibit different phenotype under drought in different climatic conditions (i.e. plasticity). Phenotypic plasticity is defined as the amount by which the expressions of individual characteristics of a genotype are changed by different environments and grapevine has been shown to be quite phenotypically plastic. Nevertheless, the plasticity of the vine response to an abiotic stress such as drought was never studied before.

The extent of the impairment between water supply/availability and demand determines the water stress degree experienced by a plant. However, to date, little research was performed to understand if a similar water stress degree in two different environments (e.g. cool and warm) is followed by a similar plant metabolic response. This project is specifically designed to fill such gap, exploring the metabolic plasticity of grapevines under drought and different climatic conditions. The results would allow to better model the grapevine adaptation mechanisms to different environments as well as to possible climate change scenarios.

Project specific objectives are:

  1. To determine what is the response of primary and secondary metabolites in grapevine leaves and berries to prolonged and short water stress in a warm or in a cool climate.
  2. To determine possible markers of water stress in grapevine leaves and berries (e.g. green leaf volatiles GLV, amino acids, minor sugars, lipids….) and its relation to environment (climate).
  3. To determine what is the adaptation mechanisms to water stress adopted by the plants under warm or cool climates in terms of physiological parameters such as leaf osmoregulation, stomatal closure, leaf area reduction (extent of leaf shedding).
  4. To determine if/what morphological/anatomical traits are different as a result of plant development under two different climates and to what extent such traits influence the plant water relations (e.g. xylem architecture, leaf area, total biomass, etc.).

The proposed approach will allow us to answer open questions pivotal to assess the grapevine resilience to drought under different climatic scenarios such as: What is the maximum water stress intensity before detrimental effects are observed for winegrape production in a cool vs warm climate? What happens to key berry metabolites such as malate, anthocyanins or aroma compounds under drought in a climate with average maximum summer temperatures of 30°C (Vipava) vs one with 25°C (Tulln)? Is metabolic response to water stress in two distinctively different climates organ specific (grape berry and leaves)?

Expected outcomes:

i) The project will provide better understanding of a) grapevine adaptation physiology to the environmental stress and its irreversibility and b) reprogramming of grape berry and leaf primary and secondary metabolism as a consequence of water deficit, climate, or both in well characterized semi-controlled or fully controlled environments;

ii) New biomarkers from central C-N metabolism (minor sugars) or secondary metabolism (polyphenols or GLV), regulated either by limited water availability, climate or combination of both will be emphasized;

iii) Molecules strongly involved in plant response to water deficit conditions, independently and in relation to the environment (climate) in grapevine leaves and fruits, are expected to be identified; which is to date, still a poorly explored topic. We hypothesize that minor sugars, GLV or certain polyphenols, as well as glutathione and terpenoids, could play and important role.

The project expected results extend current knowledge on the genotype x environment interaction with focus on the response to drought, providing a valid basis to further study abiotic stressors interaction, possible consequences of climate change, and a general better modeling of vine metabolic regulation under drought.

Methods:

To achieve objectives, the project will be divided in three main experimental setups:

1) Water deficit experiments carried out in two different locations (Tulln, Austria and Vipava, Slovenia), using the same genotype previously grown during 2 years in one single location (Austria) to guarantee homogeneity among the plants.

2) Water deficit experiments carried out in fully controlled conditions inside a greenhouse (Figure 4a).

3) Phenotyping of a single genotype planted and grown in two different locations (Tulln, Austria and Vipava, Slovenia) from year 1, to characterize the vine phenotypic plasticity due to climate eliminating all other factors.

Partners: BOKU university, UNG, KIS

Duration: 2020-2023

Financers: FWWF and ARRS

Project leaders: Dr. Jose Carlos Herrera (BOKU) and Dr. Guillaume Antalick

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