Role of Fungal Avirulent Pathogens in the Defence Response of Strawberry

CHALFOUN, NADIA REGINA; HAEL CONRAD, VERÓNICA; GRELLET BOURNONVILLE, CARLOS F.; MARTOS, GUSTAVO G.; MARTÍNEZ ZAMORA, MARTÍN GUSTAVO; DIAZ RICCI, JUAN C; TONELLO, URSULA; PERATO, SILVIA MARISA

Strawberry. Growth, Development and Diseases

CAB International

Lugar: London; Año: 2016; p. 53 - 70

Anthracnose disease, caused by fungal species of the genus Colletotrichum, representsone of the major fungal diseases of strawberry(Fragaria×ananassa Duch.), affecting all tissues of the plant: fruits, flowers, leaves, runners, roots and crowns. There are three principal Colletotrichum spp. involved in the disease: Colletotrichum acutatumJ.H. Simmonds, Colletotrichum fragariae A.N. Brooks and Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. Chemical control of the disease relies on foliar application of fungicides. However, the use of fungicides often yields por results when the weather conditions favor the disease development, or the treatment must be limited due to restrictions imposed on pesticide usage. Therefore, elicitor-induced plant resistanc represents one sustainable strategy to develop new methods to control anthracnose. However, to achieve reliable results, it is necessary to understand the mechanisms activated in plants during the interactionwith pathogens. Using double infection experiments, it was reported that an avirulent isolate of C. fragarie (F7) provided strawberry plantsof the cultivar ?Pájaro? with efficient protection against a virulent isolate of C. acutatum (M11); the protection was due to activationof a plant defence response. Later, it was demonstrated that the resistance acquired by strawberry plants treated with this avirulent isolate was of the SAR type and that it could be passed from mother to daughter plants through the runners. Recently, it was reported that this type of resistance could also be induced by other avirulent pathogens,namely: isolate M23 of C. fragariae and isolate SS71 of Acremonium strictum, suggesting that avirulent fungal pathogens may use a common mechanism of activation of the defence response. To analyse further the mechanisms involved in the establishment of a defence response against fungal pathogens in strawberries, the efforts of our group have beendirected towards studying the molecular and biochemical bases of the defence signalling and towards identifying putative elicitor molecules.