Drought stress tolerance in grapevine involves activation of polyamine oxidation contributing to improved immune response and low susceptibility to Botrytis cinerea.
Environmental factors including drought stress may modulate plant immune responses and resistance to pathogens. However, the relationship between mechanisms of drought tolerance and resistance to pathogens remained unknown. In this study, the effects of drought stress on polyamine (PA) homeostasis and immune responses were investigated in two grapevine genotypes differing in their drought tolerance; Chardonnay (CHR), as sensitive and Meski (MSK), as tolerant. Under drought conditions, MSK plants showed the lowest leaf water loss and reduction of photosynthetic efficiency, and expressed a lower level of NCED2, a gene involved in abscisic acid biosynthesis, compared with CHR plants. The improved drought tolerance in MSK was also coincident with the highest change in free PAs and up-regulation of the genes encoding arginine decarboxylase (ADC), copper amine-oxidase (CuAO), and PA-oxidases (PAO) and their corresponding enzyme activities. MSK plants also accumulated the highest level of amino acids, including Arg, Glu, Gln, Pro, and GABA, emphasizing the participation of PA-related amino acid homeostasis in drought tolerance. Importantly, drought-tolerant plants also exhibited enhanced phytoalexin accumulation and up-regulation of PR genes, especially PR-2 and Chit4c, compared with the sensitive plants. This is consistent with a lower susceptibility of MSK than CHR to Botrytis cinerea. Data suggest a possible connection between water stress tolerance and immune response in grapevine. Pharmacological experiments revealed that under drought conditions CuAO and PAO pathways were involved in the regulation of photosynthetic efficiency, and also of immune response and resistance of grapevine to a subsequent pathogen attack. These results open new views to improve our understanding of crosstalk between drought tolerance mechanisms and immune response.
URVVC EA 4707, University of Reims, UFR Sciences, Campus Moulin de la Housse, 51687 Reims Cedex 02, France.
Saloua
S
Hatmi
URVVC EA 4707, University of Reims, UFR Sciences, Campus Moulin de la Housse, 51687 Reims Cedex 02, France.
Charlotte
C
Gruau
URVVC EA 4707, University of Reims, UFR Sciences, Campus Moulin de la Housse, 51687 Reims Cedex 02, France.
Patricia
P
Trotel-Aziz
URVVC EA 4707, University of Reims, UFR Sciences, Campus Moulin de la Housse, 51687 Reims Cedex 02, France.
Sandra
S
Villaume
URVVC EA 4707, University of Reims, UFR Sciences, Campus Moulin de la Housse, 51687 Reims Cedex 02, France.
Fanja
F
Rabenoelina
URVVC EA 4707, University of Reims, UFR Sciences, Campus Moulin de la Housse, 51687 Reims Cedex 02, France.
Fabienne
F
Baillieul
URVVC EA 4707, University of Reims, UFR Sciences, Campus Moulin de la Housse, 51687 Reims Cedex 02, France.
Philippe
P
Eullaffroy
URVVC EA 4707, University of Reims, UFR Sciences, Campus Moulin de la Housse, 51687 Reims Cedex 02, France.
Christophe
C
Clément
Institut des Régions Arides, Aridoculture and Oasis Cropping, 4119 Medenine, Tunisia.
Ali
A
Ferchichi
URVVC EA 4707, University of Reims, UFR Sciences, Campus Moulin de la Housse, 51687 Reims Cedex 02, France aziz.aziz@univ-reims.fr.
Aziz
A
Aziz
D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism; D020171:Botrytis / Q000502:physiology*; D055864:Droughts; D006706:Homeostasis; D010084:Oxidation-Reduction; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D057865:Plant Immunity; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology; D011073:Polyamines / Q000378:metabolism*; D013312:Stress, Physiological; D027843:Vitis / Q000235:genetics / Q000276:immunology / Q000382:microbiology* / Q000502:physiology*; D000097667:Polyamine Oxidase
D006631:Amine Oxidase (Copper-Containing); D000587:Oxidoreductases Acting on CH-NH Group Donors; D045332:Photosystem II Protein Complex; D011073:Polyamines; D000097667:Polyamine Oxidase
Drought stress; immune response; photosynthesis; phytoalexins; polyamines.