First Report of Apiospora Mold on Sugarcane in China Caused by Apiospora arundinis (Arthrinium arundinis)

Abstract

Sugarcane (Saccharum officinarum L. cv. Badila) is a chewing cane cultivar in southern China. Since the first case of poisoning caused by the consumption of moldy sugarcane was confirmed in northern China in 1972, cases have occurred almost every year. It has been confirmed that Arthrinium is the pathogen that primarily occurs during improper postharvest storage (Liu xingjie, 1984). In 2019, ten moldy sugarcane stems (cv. Badila) were collected from Tang County, Baoding City, Hebei Province, China. The sugarcane flesh turned dark and was grayish-white, red, or reddish-brown. Some of them smelled musty. Symptomatic stems were surface disinfected using 75% ethanol and peeled aseptically. Small sections (3 mm3) were placed on potato dextrose agar amended with 0.01% chloramphenicol and incubated at 26 ± 2°C. Six fungal isolates were obtained from three sugarcane stems, a positive sample rate of 30%, and identified as the same fungus on the basis of morphological features owing to their formation of flat colonies that were initially white and later turned grayish white with moderate amounts of aerial mycelia. The mycelia consisted of smooth, hyaline, branched, and septate hyphae. The conidiophores were hyaline or pale brown and produced conidiogenous cells. The conidiogenous cells were pale brown, smooth, ampulliform, and 5.5 to 11.2 μm long (n=50). The conidia were brown, smooth, ellipsoidal to spherical, spherical in surface view, 4.5 to 7.4 μm in diameter, and 3.3 to 4.4 μm wide with a pale equatorial slit (n=50). The morphological characteristics of the one representative isolate, named LX1918, were identical to those of Arthrinium arundinis (Corda) Dyko & B. Sutton (Apiospora arundinis (Corda) Pintos & P. Alvarado) (Crous and Groenwald, 2013, Pintos and P. Alvarado, 2021). Genomic DNA was extracted from the mycelia to further identify the isolate. The internal transcribed spacer region (ITS rDNA), the translation elongation factor 1-alpha gene (TEF1) and the ß-tubulin gene (TUB2) were amplified using the primers ITS1/ITS4, EF1-728F/ EF-2 and T1/ Bt2b (White et al., 1990, O’Donnell et al. 1998, O’Donnell et al. 1997), respectively. BLASTn analysis of the ITS (556 bp, GenBank accession no. MW534386), TEF (434 bp, MW584370) and TUB2 (775 bp, MZ090019) sequences of isolate LX1918 showed that they were 99.43%, 99.52% and 99.74% similar to the published sequences of isolate CBS 106.12 (KF144883, KF145015 and KF144973), respectively. To confirm Koch’s postulates, pathogenicity tests were conducted in triplicate by inoculating the aseptic wounds with a conidial suspension (105/ml) of the isolate in healthy sugarcane stems. The controls were inoculated with sterile water. The sugarcane stems were incubated at 26 ± 2 °C and 86 % relative humidity in the dark. Obvious moldy symptoms appeared several days after the sugarcane stems had been inoculated. The sugarcane flesh turned reddish brown. In contrast, the control stems were asymptomatic. Ap. arundinis (Ar. arundinis) was reisolated from the inoculated and moldy sugarcane. In addition, 3-nitropropionic acid could be detected using HPLC-MS after the fungus had been cultured on potato yeast sucrose agar for 14 days. Previous studies had confirmed that 3-nitropropionic acid produced by Ar. sacchari, Ar. saccharicola and Ar. phaeospermum is the causal agent of poisoning caused by the consumption of moldy sugarcane (Hu wenjuan, 1986, Liu xingjie,1987). To our knowledge, this is the first report of Ap. arundinis (Ar. arundinis) as the causal agent of infected sugarcane and its production of 3-nitropropionic acid, which is toxic to humans. Therefore, the confirmation that Ap. arundinis(Ar. arundinis) infects sugarcane will expand our understanding of this pathogen and provide fundamental knowledge about the control of Apiospora mold to decrease the incidents of 3-nitropropionic acid poisoning.

Apiospora arundinis, a panoply of carbohydrate-active enzymes and secondary metabolites

“…Apiospora arundinis has been isolated from different plants (Martínez-Cano et al 1992 ; Bagherabadi et al 2014 ; Chen et al 2014 ; Thangaraj et al 2019 ; Liao et al 2022 ), suggesting it has the potential to produce high numbers of enzymes able to degrade complex carbohydrates, since these are major constituents of plant material. This also indicates that they are generalists rather than specialists.…”

“…One species belonging to the Apiospora genus that has been linked to infections in various crops is Apiospora arundinis . This association has led to significant crop losses annually (Martínez-Cano et al 1992 ; Bagherabadi et al 2014 ; Chen et al 2014 ; Thangaraj et al 2019 ; Liao et al 2022 ). It is crucial to note that a potent neurotoxin, 3-nitropropionic acid, has been identified in several Apiospora species.…”

Morphological and phylogenetic analyses reveal three new species of Apiospora in China

“… arundinis and Brunfelsia brasiliensis as a new host record for this species. Apiospora arundinis was introduced from Phyllostachys praecox , Castanea mollissima and Saccharum officinarum in China ( Chen et al 2014 ; Jiang et al 2021 ; Liao et al 2022 ). Comparing with the description from Chen et al (2014) (5–7 × 2–4 µm), Jiang et al (2021) (3–4 µm) and Liao et al (2022) (4.5–7.4 × 3.3–4.4 µm), the conidia in this study show larger sizes (6.4–10.4 × 5.2–8.3 µm).…”

Surveillance of Landraces’ Seed Health in South Italy and New Evidence on Crop Diseases

“…In Italy, it was found in the Florence Cathedral to cause the blackening of white marble [ 43 ] and it was isolated also from the environment in a library in Veneto [ 44 ]. The pathogenicity of this species was reported to cause different symptoms, such as a reddish stem in sugarcane and necrosis in bamboo in China, and necrotic lesions in rosemary in Iran [ 45 , 46 , 47 ]. This is the first report of A. arundinis on the common bean worldwide.…”