Field and laboratory screening of anthurium cultivars for resistance to foliar bacterial blight and the induced activities of defence-related enzymes

Abstract

Bacterial blight (BB) caused by Xanthomonas axonopodis pv. dieffenbachiae (Xad) is the most destructive disease of ornamental anthurium. In the present study, foliar resistance of 21 anthurium cultivars were assessed under shaded field and laboratory conditions by injection inoculation of 3 × 10 8 cfu/ml Xad; disease severity was evaluated using a pretransformed rating scale after symptoms survey. Then six selected cultivars with different resistance levels were evaluated for the induced activities of six defence-related enzymes. The obtained results indicated that the same cultivar shared identical resistance under both conditions, but there was a great variation among the cultivars. Anthurium cv. Pink Champion and Manaka showed the highest resistance, and five other cultivars were highly susceptible. The activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) in the resistant cultivars increased much faster and reached much higher peak levels than those in susceptible cultivars. Further analyses revealed that the relative resistance index (RRI) significantly positively correlated with the activities of SOD, APX, POD and PAL, but not with catalase (CAT) and polyphenol oxidase (PPO), suggesting that early rapid accumulation of SOD, APX, PAL and POD might be an important mechanism of defence against Xad and could serve as one of the valuable physiological indices for the prediction of BB resistance in anthurium germplasm. Consequently, the identified resistant cultivars and the induced defence enzymes will facilitate the phytopathological research and enhance blight resistance selection in future breeding. Key word s: anthurium (Anthurium andreanum Lind), antioxidative enzymes, bacterial blight, enzyme activity, Xanthomonas axonopodis pv. dieffenbachiae Abbreviations:APX -ascorbate peroxidase, BB -Bacterial blight, CAT -catalase, CFU -colony forming units, dpi -days post-inoculation, DSI -disease severity index, PAL -phenylalanine ammonia-lyase, POD -peroxidase, ROS -reactive oxygen species, RRI -relative resistance index, SOD -superoxide dismutase, Xad -Xanthomonas axonopodis pv. dieffenbachiae

Comparative transcriptome analysis of resistant and susceptible Kentucky bluegrass varieties in response to powdery mildew infection

“…Superoxide dismutase (SOD), peroxidase (POD), hydroperoxidase (CAT) and ascorbate peroxidase (APX) together constitute the antioxidant system of plants to remove excess ROS under stress conditions [ 36 ]. With the increase of pathogen infection time, the SOD and APX activities of ‘BlackJack’ initially increased and then decreased, reached a maximum on the 5th day after inoculation, and were significantly higher on the 9th day than 0th day (Fig.…”

Differential Responses of Cucurbita pepo to Podosphaera xanthii Reveal the Mechanism of Powdery Mildew Disease Resistance in Pumpkin

“…Among all the phenylpropanoid pathway defense enzymes, PAL is the first enzyme that produces the precursors for lignin and phenolic secondary metabolites (Sticher et al, 1997). PPO is another key enzyme in the synthesis of phenolic compounds with antimicrobial activity (Babu et al, 2015;Jia et al, 2016;Niu et al, 2018). Muslim et al (2019) revealed that the lignin deposition in cucumber plants can prevent the pathogen Colletotrichum orbiculare infection, and also the level of total phenolics was increased in cucumber seedlings after being inoculated with the P. xanthii (Chen et al, 2014).…”

“…One of the earliest responses is the rapid generation of reactive oxygen species (ROS) such as hydrogen peroxide (H 2 O 2 ), hydroxyl radical (OH − ), and superoxide anion (O 2− ) (Patykowski and Urbanek, 2003). ROS scavenging enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) play an essential role in regulating ROS levels and the extent of oxidative damage (Niu et al, 2018). The phenylpropanoid pathway is another defense response in higher plants (Irisarri et al, 2016;Hou et al, 2019).…”

“…Phenylalanine ammonia-lyase (PAL) is the first enzyme that participates in the formation of a series of structurally different and defensive lignin and phenolic compounds (Vogt, 2010;Wang et al, 2013;Kamalipourazad et al, 2016;Han et al, 2017). Polyphenol oxidase (PPO) is another key enzyme in the synthesis of phenolic compounds for defending against pathogens in plants ( Niu et al, 2018). In addition, previous studies revealed that SA plays an important role in fighting biotrophic pathogen infection and establishing systemic acquired resistance (SAR) (Dong, 1998;Edgar et al, 2006;Vlot et al, 2008;Fu et al, 2012).…”

Rice-Magnaporthe oryzae interactions in resistant and susceptible rice cultivars under panicle blast infection based on defense-related enzyme activities and metabolomics

“…One of these is the generation of reactive oxygen species (ROS) and establishing a balance between ROS production and scavenging during pathogen-plant interactions [ 6 ]. ROS scavenging enzymes including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) are key components for regulating ROS levels and are also pertinent to plant disease resistance [ 7 ]. Furthermore, the phenylpropanoid pathway has been acknowledged to be important in higher plants [ 8 ].…”