title: Expression of pathogenesis-related (PR) genes in avocados fumigated with thyme oil vapours and control of anthracnose.
abstract: Thyme oil (TO) fumigation (96μll(-1)) to cv. Hass and Ryan avocados significantly reduced anthracnose incidence compared to prochloraz and the untreated control. Also, enhanced activities of β-1,3-glucanase, chitinase were noted in both cultivars. TO fumigation induced the expression of both β-1,3-glucanase and chitinase genes in naturally infected fruit of both cultivars, during storage at 7 or 7.5°C for up to 21d and during subsequent simulated market shelf conditions at 20°C for 5d. However, the impact of TO fumigation on the β-1,3-glucanase gene expression was higher in both cultivars. Higher gene regulation and β-1,3-glucanase, chitinase activities were observed in cv. Ryan compared to Hass. Although TO fumigation significantly reduced anthracnose incidence in both naturally infected cultivars, the inhibitory effect was slightly higher in cv. Ryan than Hass. Thus, postharvest TO fumigation had positive effects on enhancing anthracnose disease resistance during storage and also gave a residual effect during the simulated shelf life.
authors.affiliation: Postharvest Technology Group, Department of Crop Sciences, Tshwane University of Technology, Private Bag X680, Pretoria West 0001, South Africa.
authors.forename: Malick
authors.initials: M
authors.lastname: Bill
authors.affiliation: Postharvest Technology Group, Department of Crop Sciences, Tshwane University of Technology, Private Bag X680, Pretoria West 0001, South Africa. Electronic address: SivakumarD@tut.ac.za.
authors.forename: Dharini
authors.initials: D
authors.lastname: Sivakumar
authors.affiliation: Postharvest Technology Group, Department of Crop Sciences, Tshwane University of Technology, Private Bag X680, Pretoria West 0001, South Africa; Department of Biochemistry, University of Pretoria, Private Bag X20, Hillcrest 0028, South Africa.
authors.forename: Mervyn
authors.initials: M
authors.lastname: Beukes
authors.affiliation: Department of Plant Sciences, University of Pretoria, Private Bag X20, Hillcrest 0028, South Africa.
authors.forename: Lise
authors.initials: L
authors.lastname: Korsten
mesh_terms: D063427:Food Quality; D005638:Fruit / Q000737:chemistry / Q000378:metabolism*; D005651:Fumigation / Q000379:methods*; D009822:Oils, Volatile / Q000737:chemistry*; D027421:Persea / Q000737:chemistry / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics*; D046930:Thymus Plant / Q000737:chemistry*
chemical_list: D009822:Oils, Volatile; D010940:Plant Proteins; C053376:pathogenesis-related proteins, plant
keywords: Colletotrichum gloeosporioides; Fruit quality; Persea americana; Postharvest decay; β-1,3-Glucanase and chitinase