The Physiological and Biochemical Responses of European Chestnut (Castanea sativa L.) to Blight Fungus (Cryphonectria parasitica (Murill) Barr)

Abstract

The most important disease of European chestnut (Castanea sativa Mill.) is chestnut blight caused by the fungus Cryphonectria parasitica (Murrill) Barr which induces yield reduction in Europe and North America. This study aimed to investigate the impacts of C. parasitica infection on the physiological and biochemical characteristics of European chestnut at two different growth stages, 3 and 6 weeks after the infection. The amount of photosynthetic pigments (chlorophyll-a, chlorophyll-b, and carotenoids), the relative chlorophyll content, and the photochemical efficiency of the photosystem II (PSII) were measured in the leaves above and below the virulent and hypovirulent C. parasitica infections. The highest values were measured in the control leaves, the lowest values were in the leaves of the upper part of virulent necrosis. Antioxidant enzyme activities such as ascorbate peroxidase (APX), guaiacol peroxidase (POD), and superoxide dismutase (SOD), proline, and malondialdehyde concentrations were also investigated. In each of these measured values, the lowest level was measured in the control leaves, while the highest was in leaves infected with the virulent fungal strain. By measuring all of these stress indicator parameters the responses of chestnut to C. parasitica infection can be monitored and determined. The results of this study showed that the virulent strain caused more pronounced defense responses of chestnut’s defense system. The measured parameter above the infection was more exposed to the blight fungus disease relative to the leaves below the infection.

Examination of Different Sporidium Numbers of Ustilago maydis Infection on Two Hungarian Sweet Corn Hybrids’ Characteristics at Vegetative and Generative Stages

“…The Cucumber Green Mottle Mosaic Virus infection induced higher APX, POX, and SOD activities in cucumber plants [ 84 ]. The results of Kovács et al [ 85 ] showed higher APX, POX, and SOD activities in European chestnut leaves infected with Cryphonectria parasitica . Barley plants infected with Blumeria graminis f. sp.…”

Plants interfere with non-self recognition of a phytopathogenic fungus via proline accumulation to facilitate mycovirus transmission

“…A previous explanation for this limited success is the complex structure of VCGs among C. parasitica strains in North America, which restricts CHV1 horizontal transmission. Previous studies have shown that C. parasitica infection increases proline production in chestnuts 65 , and that CHV1 transmission rates are higher in planta than in vitro 21,38,[66][67][68] . Therefore, we hypothesize that the enhanced transmission of CHV1 in chestnuts is mediated by plant proline, similarly to transmission of HAVs in S. sclerotiorum.…”

The Identification and Role of the Key Mycotoxin of Pestalotiopsis kenyana Causing Leaf Spot Disease of Zanthoxylum schinifolium

“…(a) Determination of SOD activity: SOD activity was determined using the NBT photoreduction method [50]. Absorbance at 560 nm was measured using a spectrophotometer, and the specific activity was calculated based on the 50% inhibition of NBT photoreduction.…”