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Amorphophallus konjac, commonly called voodoo lily, is a cash crop widely cultivated in southwest China (Gao et al. 2022). In August 2022, leaf spot symptoms were observed in a field (1 ha) located at Fuyuan (25.67°N; 104.25°E), Yunnan, China, resulting in substantial economic losses. Brown lesions, with an incidence ranging from 20 to 40%, typically had a whitish or gray center and were surrounded by yellow halos. Microscopic observations of the spots revealed anamorphic species Cercospora chevalieri. Conidiophores were 50-150 × 4-7 µm, cylindrical, unbranched, smooth-walled, pale brown and aggregated in dense fascicles arising from a brown stroma. The conidiogenous cells were integrated, terminal or intercalary, pale brown to brown and proliferated sympodially. The conidiogenous loci were thickened and darkened, and 2-3 µm in diam. The conidia were formed singly, obclavate-cylindrical, 90-160 × 5-7 µm, with an average of 130 × 6 µm (n = 30), 6-11 septa, thin-walled, smooth, hyaline or subhyaline, straight or curved with an obtuse apex and obconically truncate base, with thickened and darkened hilum. These morphological characteristics matched those of C. chevalieri, the causal agent of leaf spot on A. paeoniifolius (Braun et al. 2014; Saccardo et al. 1913). A conidial suspension in sterile water from lesions was used to inoculate water agar, and germinated conidia were transferred to potato dextrose agar（PDA) and incubated at 27°C for 7 days. Induction of sporulation was unsuccessful using PDA, as well as malt extract agar, potato sucrose agar and synthetic nutrient-poor agar. Two out of ten isolates were selected for molecular identification and pathogenicity assay. Genomic DNA from two pure isolates (KUNCC22-12536 and KUNCC22-12537) was extracted for PCR and amplified with primers for the internal transcribed spacers (ITS: ITS1/ITS4), calmodulin (CMD: CAL228F/CAL2Rd), translation elongation factor 1-alpha (TEF1-α: 728F/986R), actin (ACT: 512F/783R), histone H3 (HIS3: CYLH3F/CYLH3R), beta-tubulin gene (TUB2: BT-1F/BT-1R) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH: Gpd1/Gpd2), respectively (Vaghefi et al. 2021). The newly generated sequences for ITS (OP719153/OP719154), CMD(OP740904/OP740905), TEF1-α (OP740910/OP740911), ACT (OP740902/OP740903), HIS3 (OP740908/OP740909), TUB2 (OP740912/OP740913), GAPDH (OP740906/OP740907) of C. chevalieri were submitted to GenBank. So far, no sequence data of C. chevalieri were available in the GenBank database. As expected, most genes (TEF1-α, ACT, CMD, HIS, TUB2 and GAPDH) showed 91 to 95% identity to their best hits within species of the genus Cercospora. The phylogenetic tree showed that sequences retrieved from two isolates obtained from the A. konjac leaf spots clustered together within Cercospora forming a strongly supported clade. To test Koch's postulates, ten four-month-old healthy A. konjac plants grown in pots were used for a pathogenicity test in a greenhouse. One leaf of each plant was inoculated with mycelial plugs, and one leaf was inoculated with a sterile PDA plug. These plants were enclosed in plastic bags for 72 h. Only leaves inoculated with mycelium plugs produced brown lesions, which appeared after 10 to 14 days on inoculated leaves. Control plants treated with sterile PDA plugs remained asymptomatic. This experiment was repeated twice with the same results. C. chevalieri was reisolated from infected leaves and identified based on morphology and Sanger sequencing of the ITS region. To our knowledge, this is the first report of C. chevalieri causing leaf spot on A. konjac and the first report of this species from China (Braun et al. 2014), which provides key information for diagnosis and management of this disease.

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Amorphophallus albus P. Y. Liu & J. F. Chen is a typical cash crop widely planted in southwest China (Gao et al., 2022). In early August of 2021, a peculiar leaf spot disease was first detected on A. albus in Ankang Academy of Agricultural Sciences manufacturing base (32°69'N, 109°02'E), Shaanxi, China. Small irregular yellow-brown spots (1 to 2 mm) were observed on the surface of A. albus leaf. Following infection of the leaf, it expanded (3 to 5 mm) and became necrotic. Nine planting bases were investigated, and approximately 75% of plants were symptomatic during the rapid expansion period of bulb growth in Hanyin, Langao and Hanbin counties, Ankang City, Shaanxi, China. Higher disease incidence was observed at temperatures above 30℃ and humidity above 80%. Twenty-seven symptomatic tissues of infected leaves were first surface sterilized by immersion in 75% ethanol for 1 minute, followed by rinsing three times in sterile distilled water. The tissues were then cut into 4-5 mm pieces, plated on 1.5% potato dextrose agar (PDA), and incubated at 28±2°C. The hyphal tip from the growing edge of colonies cultured for three days at 28±2℃ was transferred to PDA to obtain pure cultures. Fungal colonies were white, then grey to black with an unevenly distributed, fast-growing aerial mycelium covering the petri dish within five days at 28±2℃. The colony turned dark brown when maintained in the dark at 28±2℃ after seven days, then grayish brown upon sporulation after 15 days (Fig.1f-g). Conidia were brown or black, smooth, spherical to sub-spherical, single-celled (8-12 µm × 10-13µm, average 9-11.5 µm in diameter, n=5µm). The nutritional hyphae exhibited septa, and a portion of the aerial hyphae formed a long, rough conidium, giving rise to a nearly spherical apical sac (Fig.1h). The surface gave rise to several small peduncles bearing clusters of surfaced spherical conidia (Fig.1i). Surfaced spherical conidia were generated on the surface of the small peduncle (Fig.1j). These morphological features were consistent with Nigrospora oryzae (Li et al., 2017). Genomic DNA was extracted from mycelia of the pathogen using an Ezup column fungal genomic DNA extraction kit (Sangon Biotech, Shanghai, China). To confirm the identity of the pathogen, the genomic fragments for the internal transcribed spacer (ITS), LSU (28S) and BenA gene of the isolate were amplified by PCR (Wang et al., 2017) and sent for sequencing. The resultant sequence (GeneBank ID of gene ITS, LSU, BenA are OR723825, OR775345, OR277316, respectively) were compared with the voucher specimens. BLAST results showed >99% identity with those of N.oryzae (GeneBank ID of N.oryzae strain LC2707 ITS, LSU, BenA are KX985954, KY806242, KY019481, respectively). A neighbor joining phylogenetic tree with the concatenated sequences of these genes showed that A-pb169 had the closest match with N. oryzae (Fig. 2). For pathogenicity testing, fifty plants in a period of rapid expansion of bulb growth were selected. Four leaves per plant were inoculated by sprayed till runoff with a conidial suspension of the pathogen (50 µL, 1×106 conidia/ml sterile water), and incubated at 30±2℃ and 80 ± 5% humidity. Control plants received sterile water. On the third day after inoculation, a yellow-brown spot appeared on leave surfaces, the spot gradually expanded; the infection rate was 90 to 95%. Fifteen days after inoculation, infected leaves showed symptoms like those observed in the field, whereas 100 control leaves sprayed with sterile water remained symptomless (Fig.1 a-e). The pathogen was reisolated from infected leaves and confirmed as N. oryzae by morphology and molecular identification. To our knowledge, this is the first report of leaf spot disease of A. albus caused by N. oryzae in China. Since its one of the major cash crops of the southeastern China, further work is necessary to determine its spread and economic impact as well as developing sustainable disease management options.

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Amorphophallus paeoniifolius (Dennst.) Nicolson, 1885, often known as elephant foot yam, is a tropical tuber crop that originates from south-east Asia and belongs to the Araceae family. It is known for its high production potential and popularity as a medicinal plant. However, the phylogeny and genes for this species are still unavailable. In this study, the first complete chloroplast genome of A. paeoniifolius was reported and phylogenetic analysis was conducted with Araceae species. The chloroplast genome was 176,258 bp in length with 34.80% overall GC content and includes a large single-copy (LSC) region (93,951 bp), a small single-copy (SSC) region (15,013 bp), and a pair of inverted repeat (IRs) regions (33,647 bp). The chloroplast genome has 130 genes, which include 85 protein-coding genes, 37 tRNA genes, and eight rRNA genes. A maximum-likelihood (ML) phylogenetic analysis indicated that all Amorphophallus species formed a single monophyletic clade with a high bootstrap value and A. paeoniifolius was closely related to A. konjac, A. albus, A. krausei, and A. titanum. The chloroplast genome reported in this study will be useful for further taxonomic and evolutionary studies of Amorphophallus.

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Amorphophallus is a perennial monocotyledonous herbaceous plant native to the southwestern region of China, widely used in various fields such as food processing, biomedicine and chemical agriculture. However, Amorphophallus is a typical thermolabile plant, and the continuous high temperature in summer have seriously affected the growth, development and economic yield of Amorphophallus in recent years. Calmodulin (CaM), a Ca2+ sensor ubiquitous in eukaryotes, is the most important multifunctional receptor protein in plant cells, which affects plant stress resistance by participating in the activities of a variety of signaling molecules. In this study, the key gene AaCaM3 for the Ca2+-CaM regulatory pathway was obtained from A. albus, the sequence analysis confirmed that it is a typical calmodulin. The qRT-PCR results demonstrated that with the passage of heat treatment time, the expression of AaCaM3 was significantly upregulated in A. albus leaves. Subcellular localization analysis revealed that AaCaM3 localized on the cytoplasm and nucleus. Meanwhile, heterologous transformation experiments have shown that AaCaM3 can significantly improve the heat tolerance of Arabidopsis under heat stress. The promoter region of AaCaM3 was sequenced 1,338 bp by FPNI-PCR and GUS staining assay showed that the promoter of AaCaM3 was a high-temperature inducible promoter. Yeast one-hybrid analysis and Luciferase activity reporting system analysis showed that the AaCaM3 promoter may interact with AaHSFA1, AaHSFA2c, AaHSP70, AaDREB2a and AaDREB2b. In conclusion, this study provides new ideas for further improving the signal transduction network of high-temperature stress in Amorphophallus.

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Amorphophallus muelleri BI was included in the Araceae family, which is a type of tuber. It is a tuber with high potential due to its abundant bioactive compounds. Amorphophallus muelleri BI flour (AF) contains a high glucomannan and carbon compounds that serve as nutrients for probiotic bacteria. Although Amorphophallus muelleri BI thrives in Indonesia, its utilization rate in the country remains relatively low and haven't been any studies conducted regarding synbiotic powder from AF. The primary objective of this research is to develop a synergistic beverage enriched with varying concentrations of Amorphophallus muelleri BI as a prebiotic and LA as probiotic (synbiotic). The process starts with culture preparation, synbiotic drink process, synbiotic and microencapsulation, includes the examination of solubility, proximate analysis, calorie content, viability, and shelf life. Results showed that the proximate and solubility had no significant effect. Synbiotic drink powder from AF can be produced using spray dry technology. The highest LA growth was observed when augmenting the AF quantity at a 0.4% concentration, which can be seen from the viability parameter with a value of 7.29 log CFU/g. Samples shelf life at -21 and 3 °C with LA viability critical parameter was determined to be 4 days.

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Diabetes mellitus is a chronic condition defined by elevated blood sugar levels (hyperglycemia). This condition can lead to complications such as nephropathy, which is histologically shown with glomerulosclerosis. Glucomannan, a component of Amorphophallus muelleri, offers numerous health benefits, but its direct therapeutic effect on glomeruli remains uncertain. Male Wistar rats which were taken with random sampling (n = 30) were distributed into six distinct groups. All groups, excluding Group N, received 125 mg/kg BW single intraperitoneal dose of alloxan. Group N received a single dose of PBS 125 mg/kg BW. After 7 days, Group K + was induced with acarbose at a dose of 50 mg/70 kg BW (adjusted using a factor of 0.018) orally per day. Groups N and K - induced with 1% CMC Na at 0.2 mL/0.1 kg orally per day. While Group P1, P2, and P3 were orally given A. muelleri ethanolic extract orally per day at a dose of 100, 200, and 400 mg/kg BW. The following 50 days of treatment, the Wistar rats were euthanized, and their kidney was preserved for histological slides that were stained with hematoxylin and eosin. The oral administration of A. muelleri ethanolic extract in alloxan-induced diabetic rats led to a significant decrease in the average of glomerulosclerosis instances when compared to the K - group. The most effective dose was observed at 400 mg/kg BW per day. A. muelleri administration leads to a reduction in glomerulosclerosis occurrences, suggesting its potential as a therapeutic approach for reducing complications probability linked to hyperglycemia.

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Starch-based biofilms are biodegradable, but their application is limited by lower mechanical strength and absence of antimicrobial properties. In this context, the present study attempted to unleash the potential of nanotechnology for synthesizing nano-starch (NS) and tannic acid-coated nano-starch (T-NS) for augmenting the tensile strength and antimicrobial properties of starch-based biofilms. Moreover, this study reports one of the first such attempts to improve the commercial viability of starch extracted from the corms of Amorphophallus paeoniifolius. In this study, NS and T-NS samples were first synthesized by the physical and chemical modification of the native starch (S) molecules. The NS and T-NS samples showed significantly smaller granule size, lower moisture content, and swelling power. Further, amendments with NS and T-NS samples (25 % and 50 %) to the native starch molecules were performed to obtain biofilm samples. The NSB (NS amended) and T-NSB (T-NS amended) biofilms showed comparatively higher tensile strength than SB films (100 % starch-based). The T-NSB showed greater antimicrobial activity against gram-positive and gram-negative bacteria. All the biofilms showed almost complete biodegradation in soil (in 10 days). Therefore, it can be concluded that additives like NS and T-NS can improve starch-based biofilms' mechanical strength and antimicrobial properties with considerable biodegradability.

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Species in the Amorphophallus genus are important cash crops in many tropical and subtropical Asian countries. Although several molecular markers have been employed to determine relationships and assess genetic variation in the Amorphophallus genus, some conflicts remain in infrageneric classification and evolution. To aid in the phylogenetic research of the Amorphophallus genus, we collected one sample of Amorphophallus tonkinensis Engler and Gehrmann 1911 from southwestern China. We assembled the first chloroplast genome of this species using high-throughput sequencing. The assembled genome was 169,341 bp long with a typical quadripartite structure (GenBank accession number: PP234804). The lengths of the large single-copy region, small single-copy region, and two inverted repeats were 90,705 bp, 15,640 bp, 31,498 bp, and 31,498 bp, respectively. We annotated 129 genes across the chloroplast genome of A. tonkinensis. The phylogenetic trees suggested that the Amorphophallus species distributed in continental Asia split into two main clades. The chloroplast genome reported in our study provided valuable genomic resources for the future phylogenetic research of the Amorphophallus genus.

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Amorphophallus muelleri is an Araceae plant with perennial tuber, widely used in food, pharmaceutical and chemical industry due to its richness in glucomannan. In April 2022, an outbreak of a target spot on A. muelleri plantlets was observed in a nursery in Ruili, Yunnan, China. The leafstalks of the diseased plantlets in the nursery turned brown and decayed (Fig.1 A-B), then gradually some water-soaked spots on the true leaves developed along the veins (Fig.1 A). Subquencely, the spots on the true leaves turned dark green to white-grayish in the center, which formed light to dark brown concentric rings with a target-like appearance surrounded by a yellow halo (Fig.1 C). When the temperature was 20-34℃ and the relatively humidity was 25-80%, dark-green to black sporodochia with white hypha appeared on the lower and upper leaf surfaces. Finally, 5-8% of the plants surveyed on 800 m2 of one-year-old plantlets in the nursery showed the symptoms and some plants with infected leafstalks would be death. Similar symptoms were also observed on about 10% of the transplanted plants surveyed on 12000 m2 (1.2 ha) of two-year-old plantlets in the field. Five diseased leaves from five distinct plantlets in the nursery were collected for pathogen isolation. Leaf pieces(5 x 5 mm) were cut from the edge of necrotic lesions, and surface-sterilized with 2.5% sodium hypochlorite for 1 min, 75% ethanol for 30 s, then rinsed 5 times by sterilized distilled water, finally put the leaf pieces on sterilized filter paper for 3-5 minutes to dry them and transferred onto potato dextrose agar (PDA) in petri dishes at 25℃ for three days. Five pure cultures identical to colony and conidial characteristics were isolated from five individual plants. The representative pure culture (M1) was grayish-white and circular colonies were 7.50 cm in diamter after 15 days at 25℃, with dark green concentric rings of sporodochia, the dorsal view of the colonies were yellowish. Conidia were aseptate, smooth, cylindrical, 5.00-6.25 (5.71) x 1.25-1.67 (1.63) µm (n = 20) rounded at both ends. A spore suspension (1 x 106 spores/ml) was prepared by harvesting spores from 15-day-old cultures grown in the dark at 25℃, then a thirty-ml of spore suspension was sprayed on the healthy leaves of 10 two-year-old plantlets. Thirty-ml of sterile water was sprayed on the healthy leaves of another 10 seedlings and used as the control. All seedlings were placed in a nursery at 20 to 34℃ and a relative humidity of 25 to 80%. Similar symptoms (Fig.1 D-F) to those observed in the nursery and field developed on all the 10 seedlings inoculated with M1 after two days, but not on the control leaves. The pathogenicity tests were repeated for three times. Fungal cultures reisolated from the infected leaves were identical to the original colonies and conidia, completing Koch's postulates. The internal transcribed spacer (ITS, primers ITS1 and ITS4) region of ribosomal DNA (OQ553785), calmodulin (cmdA, primers CAL-228F and CAL2Rd)(OQ559103), RNA polymerase II second largest subunit (rpb2, primers RPB2-5F2 and RPB2-7cR) (OQ559104) and ß-tubulin (tub2, primers Bt2a and Bt2b) (OQ559105) of M1 had 100%, 98.52%, 98.98% and 98.98% identity with the sequences of Paramyrothecium breviseta CBS544.75 (KU846289 for ITS, KU846262 for cmdA, KU846351 for rpb2, and KU846406 for tub2), respectively. In the phylogenic tree based on ITS, cmdA, rpb2 and tub2 gene sequences, the pure culture M1 clustered with P. breviseta CBS544.75, SDBR-CMU387, DRL4 and DRL3, which has been reported as the pathogen of leaf spot of Coffea arabica in China, C. canephora in China and Thailand (Wu et al. 2021; Withee et al. 2022). Molecular and morphological observations showed the pure culture M1 were P. breviseta (Withee et al. 2022), in addition the disease was named as target spot dueing to the typical target symptom on the leaves. To our knowledge, this is the first report of P. breviseta on A. muelleri from Yunnan, China, as well as worldwide. This disease can caused serious economic losses of A. muelleri dueing to that it can result 5-8% death of the plants in the nursery.

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Konjac glucomannan consists of D-mannose and D-glucose units and is a hydrocolloid obtained from the corm of Amorphophallus species. Due to its bioactive properties, biodegradability, and hydrophilic ability, glucomannan is widely used in the fields of food, medicine, and industry. Amorphophallus species have been cultivated as cash crops in many Asian countries. Amorphophallus kachinensis Engler & Gehrmann 1911 is naturally distributed in southwestern China, Laos, and northern Thailand. To help the genetic assessment and conservation of this species, the first chloroplast genome of A. kachinensis was sequenced on the Illumina sequencing platform. We assembled the chloroplast genome using the software GetOrganelle and annotated the genome by Geseq and Cpgavas 2. The assembled chloroplast genome was 173,330 bp long, and the average GC content was 35% (GenBank accession number: PP072244). The chloroplast genome of A. kachinensis contained one large single copy, one small single copy, and two inverted repeats, with lengths of 92,030 bp, 15,118 bp, 33,091 bp, and 33,091 bp, respectively. We successfully annotated 132 genes across the genome, which was consistent with other Amorphophallus species. The phylogenetic tree indicates a sub-divergence in the Amorphophallus genus with two main genetic groups detected among eight species. The two genetic groups should be treated as distinct evolutionarily significant units when making conservation strategies. Our study enriched the chloroplast genome resources of the Amorphophallus genus and could help future phylogeographic studies, protection, and utilization of wild resources.

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The mountainous region of southern China has been characterized by its complicated environment and topography. Amorphophallus kiusianus Makino 1913 is a representative species of extreme habitat preference that resides mainly in this region. To help study the genetic differentiation mechanisms of A. kiusianus populations, we sequenced the first chloroplast genome of this species using next-generation sequencing. The chloroplast genome was 166,269 bp in length with an average GC content of 36% (GenBank accession number: PP072243). The lengths of the large single-copy region (LSC), small single-copy region (SSC), and two inverted repeats (IRs) were 90,701 bp, 14,802 bp, 31,383 bp, and 31,383 bp, respectively. One hundred and twenty-nine genes were annotated in the chloroplast genome, including 84 protein-coding genes, 8 rRNA genes, and 37 tRNA genes. The phylogenetic tree suggested a close relationship among A. kiusianus, A. yunnanensis, and A. coaetaneus. The chloroplast genome reported in this study provides valuable genomic resources for the future phylogeographic research of A. kiusianus.

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This work determined and analyzed the complete chloroplast genome sequence of Amorphophallus konjac K. Koch ex N.E.Br 1858 from Yunnan, China. The genome size was 167,470 bp, of which contains a large single-copy region (LSC 93,443 bp), a small single-copy region (SSC 21,575 bp), and a pair of inverted repeat regions (IR 26,226 bp). The chloroplast genome has 131 genes, including 86 protein-coding genes, 37 tRNAs, and eight rRNAs. A previous study reported deletion of accD, psbE, and trnG-GCC genes in the A. konjac chloroplast genome. Our study supports the conservative structure of A. konjac and does not support the gene deletion mentioned above. Phylogenetic analysis indicated that A. konjac shares a close relationship with another A. konjac (collected from Guizhou) and A. titanium by forming a clade in the genus Amorphophallus. Our results provide some useful information to the evolution of the family Araceae.

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The role of geographical isolation and environmental adaptation in driving the differentiation and radiation of species has been a hotspot in evolutionary biology. The extremely complicated and fragmented geography of the mountainous region of Southwest China provides an excellent system for investigating the process of species divergence in heterogeneous habitats. Amorphophallus yunnanensis is a species of extreme habitat preference that resides mainly in the mountainous region of Southwest China. Here, we used restriction site-associated DNA sequencing (RAD-seq) to characterize the geographic pattern of genetic variation among 19 populations of A. yunnanensis as well as the genomic basis of environmental adaptation. A pattern of low population genetic diversity and high level of genetic differentiation was observed. The genomic data revealed a clear east-west genetic differentiation, with two distinct genetic lineages corresponding to the Guizhou plateau and Yunnan plateau, respectively. However, we discovered demographic expansion of the Guizhou Plateau lineage and recent hybridization in populations at the contact region. Significant levels of isolation by distance along with isolation by environment were detected. Outlier tests and genome-environment association analyses identified 89 putatively adaptive loci that might play a role in environmental adaptation. Our results suggest that the genetic divergence of A. yunnanensis is attributed to geographical isolation together with divergent selection in the mountainous region of Southwest China.

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The genus Amorphophallus belongs to the family Araceae. Plants belonging to this genus are available worldwide and have been used in traditional medicines since ancient times, mainly in Ayurveda and Unani medical practices. Amorphophallus species are an abundant source of polyphenolic compounds; these are accountable for their pharmacological properties, such as their analgesic, neuroprotective, hepatoprotective, anti-inflammatory, anticonvulsant, antibacterial, antioxidant, anticancer, antiobesity, and immunomodulatory effects, as well as their ability to prevent gastrointestinal disturbance and reduce blood glucose. Moreover, Amorphophallus species contain numerous other classes of chemical compounds, such as alkaloids, steroids, fats and fixed oils, tannins, proteins, and carbohydrates, each of which contributes to the pharmacological effects for the treatment of acute rheumatism, tumors, lung swelling, asthma, vomiting, abdominal pain, and so on. Additionally, Amorphophallus species have been employed in numerous herbal formulations and pharmaceutical applications. There has been no extensive review conducted on the Amorphophallus genus as of yet, despite the fact that several experimental studies are being published regularly discussing these plants' pharmacological properties. So, this review discusses in detail the pharmacological properties of Amorphophallus species. We also discuss phytochemical constituents in the Amorphophallus species and their ethnomedicinal uses and toxicological profiles.

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The type and content of carbohydrates in konjac corms are an essential factors in determining the quality of konjac; however, the pattern of carbohydrate changes and the mechanism regulating the development of mother and daughter corms in the "relay growth" process of Amorphophallus muelleri remain unclear. This study aimed to investigate changes in corm carbohydrates during the growth cycle of A. muelleri and to compare the carbohydrate composition and the expression of related genes between mother and daughter corms. Integrated metabolome and RNA-seq analyses identified 37 differential metabolites as well as 8074 genes that were differentially expressed between mother and daughter corms, the majority of which were involved in starch and sucrose metabolism. More than 80% of the differential metabolites, including sucrose and starch, tended to accumulate in the mother corms; however, konjac glucomannan (KGM), as one of the most important carbohydrates and its major component of the corm, accumulated in higher amounts in the daughter corms. In addition, the expression of invertase and alpha-amylase that promote the breakdown of sucrose and starch was 351.78- and 15.63-fold higher, respectively, in the daughter corm, whereas that of the starch synthesis gene AkWAXY was only 0.096 times as high as in the mother corms. Furthermore, the level of cellulose synthase-like protein G, which promotes KGM synthesis, was 3.85 times higher in daughter corms compared to mother corms. Thus, we inferred that the daughter and mother corms had two distinct carbohydrate utilization strategies. This study provides insights into temporal changes in carbohydrates during the growth cycle of A. muelleri.

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Konjac (Amorphophallus konjac) is a perennial herbaceous plant of the Araceae family, cultivated mainly in south-western China and used extensively for weight loss (Chua et al. 2010). In June 2022, leaf blight was detected on a 2,00 ha A. konjac plantation in Chenxi County, Huaihua City, Hunan Province. It infected almost 20% of the area under cultivation and tends to occur each year during warm, humid weather from May to July, causing significant economic losses to A. konjac production. There were small brown spots on the leaves which gradually spread to form irregular brown lesions. In severe cases the entire plant turned yellow and died. Nine samples were collected randomly from different plants in three plantation forests to isolate the pathogens. They were washed with sterile water and the lesions were excised. They were subsequently disinfected with 3% hydrogen peroxide for 30 s, 75% ethanol for 90 s and rinsed three times with sterile water. The cut sections were then placed on water agar plates and grown in the dark in a constant temperature incubator at 28℃ for 3-5 days, when mycelia grew they were transferred to potato dextrose agar medium and grown in the dark at 28℃ for 3-5 days. Eleven purified fungal isolates were obtained, ten of which looked like Fusarium (90.9% isolation rate), and three representative isolates (MY5, MY7 and MY9) were chosen for further study. The fungal colonies initially appeared white and gradually turnned dark red. Macroconidia were crescent-shaped, elongated, slightly curved and had 2 to 4 septations, with a predominance of 3 septations. They measured 15.540 to 42.083 × 2.760 to 4.558 µm (n=100). Microconidia were oval or pyriform, with a maximum of one septum and measured 6.135 to 24.990 × 2.158 to 4.412 µm (n=100). Two genetic regions, the translation elongation factor-1 (TEF1-α) and RNA polymerase II largest subunit (RPB1) genes, were amplified and sequenced to verify the identity of the fungus (Qiu et al. 2023). The universal primers TEF1-F/R, G2R/Fa were used for amplification and sequencing, and the sequences were submitted to GenBank (TEF1-α: OR545395, OR545397, OR545399; RPB1: OR545394, OR545396, OR545398). A joint phylogenetic tree of the two genes was constructed and analysis showed that the three isolates were significantly clustered with Fusarium tricinctum. Based on the results of morphological identification and phylogenetic tree analysis, the three isolates were identified as F. tricinctum. Pathogenicity tests were carried out on 12 uniformly growing leaf expansion stages of konjac plants，each inoculated with five young leaves. Mycelial blocks of 6 × 6 mm grown on PDA media for 5 days were placed on the surface of the leaves, while sterile PDA blocks were placed on the control plant. After 10 days of rearing the treated plants in a constant temperature chamber at 28°C and 90% relative humidity, the lesions appeared and the pathogens re-isolated from the diseased tissues had the same morphological characteristics as representative isolates. F. tricinctum has been shown to be the major pathogenic fungus causing leaf blight in wheat (Triticum aestivum L.) (Castañares et al. 2011) and orchardgrass (Dactylis glomerata L.) (Wu et al. 2020). To our knowledge, this is the first time in the world that F. tricinctum has been reported to cause leaf blight in A. konjac. This research could provide a foundation for future control of leaf blight disease.

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Amorphophallus coaetaneus S. Y. Liu & S. J. Wei 1986 is a perennial herb belonging to the Araceae family in southwestern China (Guangxi and Yunnan provinces). Although this species have not been list in the red list of International Union for Conservation of Nature (IUCN), the populations are declining due to human over exploitation. To help to genetic diversity studies, we sequenced and assembled the complete chloroplast (cp) genome of A. coaetaneus (GenBank accession number of national center for biotechnology information (NCBI): OQ404947). The assembled genome revealed 175,465 bp in length with a GC content of 34.90%, including a large single-copy (LSC) region (98,561 bp), a small single-copy (SSC) region (16,504 bp) and two inverted repeat regions (IRs) (30,200 bp each). A total of 133 genes were annotated, of which 85 are protein-coding genes, 40 are tRNA genes and 8 are rRNA genes. As an output of this study, a maximum likelihood (ML) phylogenetic inference of 16 Araceae species clustered all four Amorphophallus species in one clade, and showed a relatively close relationship between the tribes Pythonieae and Colocasieae. The cp genome will serve as a basis in a more extensive molecular works covering all possible extant population of Amorphophallus, as well as conservation, breeding, and other ethnobotanical utilization of this species.

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Combined with the Konjac transcriptome database of our laboratory and internal reference genes commonly used in plants, the eight candidate internal reference genes were screened and detected. They are the 25S ribosomal RNA gene (25S rRNA), 18S ribosomal RNA gene (18S rRNA), actin gene (ACT), glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH), ubiquitin gene (UBQ), ß-tubulin gene (ß-TUB), eukaryotic elongation factor 1-αgene(eEF-1α), and eukaryotic translation initiation factor 4α-1 gene (eIF-4α). The results of GeNorm, Normfinder, and BestKeeper were analyzed comprehensively. The data showed that the expression levels of 25S rRNA, 18S rRNA, and ACT at the reproductive periods, eEF-1α and eIF-4α at the nutritional periods, and eEF-1α, UBQ, and ACT at different leaf developmental periods were stable. These identified and stable internal reference genes will provide the basis for the subsequent molecular biology-related studies of Konjac.

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Introduction: Amorphophallus albus is an herbaceous, cormous, perennial plant used as a food source and traditional medicine in Asia. Methods: In this study, we assembled and annotated the complete mitochondrial genome (mitogenome) of A. albus. Then we analyzed the repeated elements and mitochondrial plastid sequences (MTPTs), predicted RNA editing sites in mitochondrial protein-coding genes (PCGs). Lastly, we inferred the phylogenetic relationships of A. albus and other angiosperms based on mitochondrial PCGs, and designed two molecular markers based on mitochondrial DNA. Results and discussion: The complete mitogenome of A. albus consists of 19 circular chromosomes. And the total length of A. albus mitogenome is 537,044 bp, with the longest chromosome measuring 56,458 bp and the shortest measuring 12,040 bp. We identified and annotated a total of 36 protein-coding genes (PCGs), 21 tRNA genes, and 3 rRNA genes in the mitogenome. Additionally, we analyzed mitochondrial plastid DNAs (MTPTs) and identified 20 MTPTs between the two organelle genomes, with a combined length of 22,421 bp, accounting for 12.76% of the plastome. Besides, we predicted a total of 676 C to U RNA editing sites on 36 protein-coding genes of high confidence using Deepred-mt. Furthermore, extensive genomic rearrangement was observed between A. albus and the related mitogenomes. We conducted phylogenetic analyses based on mitochondrial PCGs to determine the evolutionary relationships between A. albus and other angiosperms. Finally, we developed and validated two molecular markers, Ai156 and Ai976, based on two intron regions (nad2i156 and nad4i976) respectively. The discrimination success rate was 100 % in validation experiments for five widely grown konjac species. Our results reveal the multi-chromosome mitogenome of A. albus, and the developed markers will facilitate molecular identification of this genus.

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The rhizosphere is a narrow soil area directly affected by plant root exudates. Microbes inhabiting the rhizosphere have been widely studied for their beneficial effects on plant nutrition, growth, and disease prevention. Many factors affect the rhizosphere microbial composition, including plant pathogen infection. Here, we analyzed the bacterial community structure in the rhizosphere of fungi-infected Amorphophallus titanum. Soil samples were collected from rhizosphere and non-rhizosphere areas of fungi-infected A. titanum. The 16S metagenomic analysis was conducted to investigate the bacterial community of the samples by amplifying the V3-V4 region. The results showed that the phylum Firmicutes was prevalent in the rhizosphere, whereas the phyla Proteobacteria, Acidobacteria, and Actinobacteria were limited. Some major fungal genera were isolated from infected tubers and rhizosphere soil of A. titanum, including Trichoderma sp., Aspergillus sp., Perenniporia sp., and Cerrena sp. The fungal-isolate Aspergillus spp. is a well-known agricultural pest in several reports. While Cerrena sp. was reported to be pathogenic in plants, including the family of Arecaceae. Overall, the data revealed a potential relationship between fungal infections and the dominant bacterial community in the rhizosphere of A. titanum. Additionally, this research may contribute to the development of microbe-based technology to mitigate diseases in A. titanum.

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