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Anthracnose caused by Colletotrichum gloeosporioides is a destructive disease of Stylosanthes (stylo). Combination treatment of phloretin and pterostilbene (PP) has been previously shown to effectively inhibit the conidial germination and mycelial growth of C. gloeosporioides in vitro. In this study, the effects of PP treatment on the growth of C. gloeosporioides in vivo and the biocontrol mechanisms were investigated. We found that exogenous PP treatment could limit the growth of C. gloeosporioides and alleviate the damage of anthracnose in stylo. Comparative transcriptome analysis revealed that 565 genes were up-regulated and 239 genes were down-regulated upon PP treatment during the infection by C. gloeosporioides. The differentially expressed genes were mainly related to oxidative stress and chloroplast organization. Further physiological analysis revealed that application of PP after C. gloeosporioides inoculation significantly reduced the accumulation of O2•− level and increased the accumulation of antioxidants (glutathione, ascorbic acid and flavonoids) as well as the enzyme activity of total antioxidant capacity, superoxide dismutase, catalase, glutathione reductase, peroxidase and ascorbate peroxidase. PP also reduced the decline of chlorophyll a + b and increased the content of carotenoid in response to C. gloeosporioides infection. These results suggest that PP treatment alleviates anthracnose by improving antioxidant capacity and reducing the damage of chloroplasts, providing insights into the biocontrol mechanisms of PP on the stylo against anthracnose. [ABSTRACT FROM AUTHOR]

Anthracnose is a fungal disease caused by members of Colletotrichum that affect a wide range of crop plants. Strategies to improve crop resistance are needed to reduce the yield losses; and one strategy is to manipulate protein kinases that catalyze reversible phosphorylation of proteins regulating both plant immune responses and fungal pathogenesis. Hence, in this review, we present a summary of the current knowledge of protein kinase signaling pathways in plant- Colletotrichum interaction as well as the relation to a more general understanding of protein kinases that contribute to plant immunity and pathogen virulence. We highlight the potential of combining genomic resources and phosphoproteomics research to unravel the key molecular components of plant- Colletotrichum interactions. Understanding the molecular interactions between plants and Colletotrichum would not only facilitate molecular breeding of resistant cultivars but also help the development of novel strategies for controlling the anthracnose disease. [ABSTRACT FROM AUTHOR]

Anthracnose is a destructive disease that affects a wide range of crop plants especially in tropical and subtropical regions. Colletotrichum spp. are the major pathogens causing anthracnose. In this study, we collected and identified the pathogen from diseased samples of Stylosanthes, a major tropical forage crop. The ability of the pathogen to naturally infect Arabidopsis thaliana was examined. Sequence analysis of ITS, ACT, CHS, and GAPDH genes showed the pathogen to be Colletotrichum gloeosporioides sensu lato (s.l.), and this was supported further by morphological characterization of representative isolates. The disease symptoms and cellular infection process of aggressive isolates (DZ‐19 and HK‐04) and a weak isolate (CJ‐04) were compared. DZ‐19 and HK‐04 caused more severe disease symptoms on both young seedlings and adult plants of Col‐0 and Ws‐2 ecotypes compared to CJ‐04. Furthermore, the more aggressive isolates showed faster and earlier germination of conidia, formation of appressoria, and growth and development of hyphae during the infection. Genetic analysis of the defence response and expression profiling of defence marker genes demonstrated the involvement of MAP kinase, Ca2+‐dependent protein kinase, salicylic acid, ethylene, and jasmonic acid pathways in the resistance against anthracnose. These results suggest that the Arabidopsis–Colletotrichum gloeosporioides pathosystem should provide a valuable tool for exploring the resistance mechanisms against this pathogen. [ABSTRACT FROM AUTHOR]

Colletotrichum gloeosporioides sensu lato (s.l.) is one of the most economically and scientifically important fungal pathogens, causing serious diseases in tropical and subtropical region. The detection of C. gloeosporioides s.l. is of importance for disease control. In this study, an ACT-based real-time PCR assay was developed for quantification of C. gloeosporioides s.l., which reliably detected as little as 100 fg genomic DNA, 100 copies of target DNA and 20 conidia. This method could recognize all four tested C. gloeosporioides s.l. isolates, while no amplification was observed in other Colletotrichum species and Botrytis cinerea , indicating the specificity of this assay. Detection and quantification of C. gloeosporioides s.l. was demonstrated in artificially and naturally infected host leaves. First, the real-time PCR analysis was performed using leaf samples collected at different time points post inoculation to monitor the growth of C. gloeosporioides s.l. over time. Secondly, the method was used to compare the resistance in two Stylosanthes cultivars and two Arabidopsis cultivars. Finally, naturally infected and symptomless leaves of Stylosanthes in the fields were tested by the real-time PCR method. Overall, the real-time PCR assay could allow the detection at early symptomless phase of infection; and the results was well correlated with microscopic observation and later disease symptoms. Therefore, our studies have provided a rapid and effective detection method for studying the plant- Colletotrichum interaction as well as disease prediction and control. [Display omitted] • Established a detection method for C. gloeosporioides. • The specificity and sensitivity of the method. • Suitable for the detection in Stylosanthes and Arabidopsis. • Suitable for the natural infected host samples. [ABSTRACT FROM AUTHOR]

Colletotrichum , a hemibiotrophic fungal pathogen with a broad host range, causes a yield-limiting disease called anthracnose. Stylo (Stylosanthes) is a dominant pasture legume in tropics and subtropics, and anthracnose is one of its most destructive disease. Resistance mechanisms against anthracnose in stylo are poorly understood, thus hindering the development of resistant varieties. We performed time-resolved leaf transcriptomics, metabolomics and in vitro inhibition assay to investigate the defense responses against Colletotrichum gloeosporioides in stylo. Transcriptomics demonstrated that flavonoid biosynthetic genes were significantly induced during the infection. Consistently, metabolomics also showed the increased accumulation of flavonoid compounds. In vitro assays showed that phloretin and naringenin inhibited the mycelial growth, and apigenin, daidzein, quercetin and kaempferol suppressed conidial germination of Colletotrichum strains. Together, our results suggest that stylo plants cope with C. gloeosporioides by up-regulation of genes and compounds in flavonoid biosynthesis pathway, providing potential targets for resistance breeding. • An integrative analysis of transcriptomics and metabolomics was performed to investigate the molecular responses of Stylosanthes against Colletotrichum gloeosporioides. • Transcriptomics shows the induction of flavonoid biosynthetic genes in response to Colletotrichum. • Metabolomics reveals the increased accumulation of flavonoid compounds during the infection. • Some induced flavonoid compounds could inhibit the fungal growth in vitro. [ABSTRACT FROM AUTHOR]

Anthracnose caused by Colletotrichum gloeosporioides is one of the most destructive fungal diseases of many plants, including stylo ( Stylosanthes spp.), which is an important tropical forage legume. Although C. gloeosporioides -caused anthracnose is the major constraint limiting the growth and yield of stylo, little information is available regarding the responses of stylo during the infection process of this pathogen. This study investigated the changes in growth, the antioxidant system and gene expression in stylo in response to C. gloeosporioides treatment. Negative effects of C. gloeosporioides were observed in inoculated stylo plants, as reflected by the formation of necrotic disease lesions and the decrease in shoot fresh weight. Reactive oxygen species (ROS) accumulation increased in stylo leaves during the C . gloeosporioides infection process. The activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), glutathione peroxidase (GPX) and glutathione reductase (GR), as well as the concentrations of the antioxidant compounds ascorbate (AsA) and glutathione (GSH), increased in leaves under C. gloeosporioides treatment. Furthermore, transcriptional analysis showed that the expression of stress response genes, including NADPH oxidase ( Nox ), thioredoxin ( Thi ), pathogenesis related genes ( PR1 and PR5 ), phenylalanine ammonia lyase ( PAL ), polyphenol oxidase ( PPO ), chalcone synthase ( CHS ) and chitinase ( Cht ), was differentially enhanced in stylo leaves by C. gloeosporioides . Taken together, this study provides novel information regarding the alterations during the infection process of C. gloeosporioides in stylo at the levels of antioxidant system and gene expression. [ABSTRACT FROM AUTHOR]