Morphological and Phylogenetic Analyses Reveal Three New Species of Didymella (Didymellaceae, Pleosporales) from Jiangxi, China.

Didymella contains numerous plant pathogenic and saprobic species associated with a wide range of hosts. Over the course of our mycological surveys of plant pathogens from terrestrial plants in Jiangxi Province, China, eight strains isolated from diseased leaves of four host genera represented three new species of Didymella, D. bischofiae sp. nov., D. clerodendri sp. nov., and D. pittospori sp. nov. Phylogenetic analyses of combined ITS, LSU, RPB2, and TUB2 sequence data, using maximum-likelihood (ML) and Bayesian inference (BI), revealed their taxonomic placement within Didymella. Both morphological examinations and molecular phylogenetic analyses supported D. bischofiae, D. clerodendri, and D. pittospori as three new taxa within Didymella. Illustrations and descriptions of these three taxa were provided, along with comparisons with closely related taxa in the genus.

Multi-locus phylogenetic analyses reveal eight novel species of Distoseptispora from southern China.

IMPORTANCE: Distoseptispora as a single genus in Distoseptisporaceae was introduced by morphological and phylogenetic analyses. Members of this genus occur mainly as asexual morphs, forming effuse, hairy colonies on decaying wood, plant stems, bamboo culms, and fallen leaves and shafts in terrestrial and freshwater habitats. In the present study, saprobic hyphomycetes from plant debris were investigated, and eight new Distoseptispora species were introduced based on morphology and phylogenetic analyses of LSU, ITS, TEF1, and RPB2 sequence data. This study provides important data on the species diversity, ecological environment, and geographical area of Distoseptispora, greatly updates the classification of Distoseptispora, and improves our understanding of the taxonomy of Distoseptispora.

First Report of Colletotrichum fructicola Causing Anthracnose on Punica granatum in China.

Punica granatum L. (Pomegranate), a deciduous shrub, is widely cultivated as a fruit tree and decorative plant in China. Its flowers, leaves, roots and fruit bark also has been widely used for the treatment of different types of human disease because of the high anti-inflammatory and antibacterial activitiy (Tehranifar et al. 2011). In October 2022, leaf spot symptoms were observed on P. granatum leaves in a landscaped area on the campus of Jiangxi Agricultural University (28.75°N, 115.83°E), Nanchang, Jiangxi Province, China. A survey of 40 P. granatum of 300 m2 found that up to 20% of the foliage was infected. Infection normally starts at the tip or edge of the leaves, with the initial symptoms of lesions usually being small dark brown spots (0.8 to 1.5 mm) that gradually expand into irregular spots with grayish white central parts, and brown margins (2.3 to 3.8 mm). Ten freshly infected leaves from three different plants were collected and cut into small slices, disinfected with 75% ethanol for 30 seconds followed by 5% NaClO for 1 minute, rinsed 3 times with sterile water, and then plated on potato dextrose agar (PDA) and incubated in the dark at 25°C. After 7 days, all incubated samples produced similar morphology of aerial mycelium pale grey, dense, and cottony. Conidia were hyaline, smooth-walled, cylindrical, aseptate and measuring 12.28 to 21.05 × 3.51 to 7.37 µm (n = 50). Morphological characteristics were consistent with those of Colletotrichum gloeosporioides species complex (Weir et al. 2012; Park et al. 2018). For molecular identification, we used two representative isolates (HJAUP CH005 and HJAUP CH006) for genomic DNA extraction and amplification, using primers for ITS4/ITS5 (White et al. 1990), Bt2a/Bt2b, GDF1/GDR1, ACT-512F/ACT-783R and CL1C /CL2C (Weir et al. 2012), respectively. The sequenced loci (GenBank accession nos. ITS: OQ625876, OQ625882; TUB2: OQ628072, OQ628073; GAPDH: OQ628076, OQ657985; ACT: OQ628070, OQ628071; CAL: OQ628074, OQ628075) exhibited 98 to 100% homology with corresponding sequences of C. fructicola strains (GenBank accession nos. OQ254737, MK514471, MZ133607, MZ463637, ON457800, respectively). A phylogenetic tree was constructed using the maximum-likelihood method in MEGA7.0 for the sequences of five concatenated genes (ITS-TUB2-GAPDH-ACT-CAL). Our two isolates clustered together with three strains of C. fructicola with 99% bootstrap support values in the bootstrap test (1000 replicates). The isolates were identified as C. fructicola based on morpho-molecular approach. The pathogenicity of HJAUP CH005 was tested indoors by inoculating the wounded leaves of four healthy P. granatum plants. Four leaves from each of two healthy plants were punctured with flamed needles and sprayed with a spore suspension (1 × 106 spores/ml), and four wounded leaves from each of other two plants were inoculated with mycelial plugs (5 × 5 mm3), respectively. Mock inoculations with sterile water and PDA plugs on four leaves each were used as controls. Treated plants were incubated in a greenhouse at high relative humidity, 25°C, and a photoperiod of 12 h. After 4 days, typical anthracnose symptoms similar to natural infection appeared on the inoculated leaves, whereas the control leaves remained asymptomatic. Based on morphological and molecular data, the fungus isolated from the inoculated and symptomatic leaves was identical to the original pathogen, confirming Koch's hypothesis. Anthracnose caused by C. fructicola has been reported to affect numerous plants worldwide, including cotton, coffee, grapes and citrus (Huang et al. 2021; Farr and Rossman 2023). This is the first report of C. fructicola causing anthracnose on P. granatum in China. This disease seriously affects the quality and yield of the fruit and should be of wide concern to us.

First Report of Anthracnose Caused by Colletotrichum siamense on Hydrangea macrophylla in China.

Hydrangea macrophylla (Thunb.) Ser. (Hydrangeaceae), a shrubby perennial plant, is widely used as an ornamental flowering plant because of its showy inflorescences and colorful sepals. In October 2022, leaf spot symptom was observed on H. macrophylla in Meiling Scenic Spot, which covers an area of about 143.58 km2 in Nanchang, Jiangxi Province, China (28.78°N, 115.83°E). An investigation was carried out in a 500 m2 mountain area with 60 H. macrophylla plants in a residential garden, the incidence of disease observed was 28~35%. The symptoms were visible as nearly round dark brown spots on the leaves in the early stages of infection. At later stages, the spots gradually developed grayish white center with dark brown margins. To isolate the pathogen, seven leaves randomly selected from 30 infected leaves were cut into 4-mm2 pieces, surface disinfected with 75% ethanol for 30s followed by 5% NaClO for 1 min, rinsed in sterile water three times, placed on potato dextrose agar (PDA), and cultured at 25 °C in the dark for 7 days, and four strains with similar morphological characteristics were obtained from 7 diseased samples. Conidia were aseptate, cylindrical, hyaline, obtuse at both ends, and measured 13.31 to 17.53 × 4.43 to 7.45 µm (15.47 ± 0.83 × 5.91 ± 0.62 µm, n = 60). Morphological characteristics matched Colletotrichum siamense (Weir et al. 2012; Sharma et al. 2013). For molecular identification, two representative isolates (HJAUP CH003 and HJAUP CH004) were used for genomic DNA extraction, and the internal transcribed spacer (ITS), partial sequences of actin (ACT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ß-tubulin (TUB2) and partial calmodulin (CAL) were amplified, using primer pairs ITS4/ITS5 (White et al. 1990), ACT-512F/ACT-783R, GDF1/GDR1, Bt2a/Bt2b and CL1C/CL2C (Weir et al. 2012), respectively. The sequences were deposited in GenBank (accessions nos. ITS: OQ449415, OQ449416; ACT: OQ455197, OQ455198; GAPDH: OQ455203, OQ455204; TUB2: OQ455199, OQ455200; CAL: OQ455201, OQ455202). Concatenated sequences of the five genes were used to conduct phylogenetic analyses using the maximum-likelihood method in MEGA7.0 (Sudhir et al. 2016) and Bayesian inference analysis in MrBayes 3.2 (Ronquist et al. 2012). Our two isolates cluster together with four strains of C. siamense with 93%ML/1.00BI bootstrap support. The isolates were identified as C. siamense based on the morpho-molecular approach. Pathogenicity of HJAUP CH003 was tested indoors by inoculating detached wounded leaves of six healthy H. macrophylla plants. Three healthy plants with three leaves were punctured with flamed needles and sprayed with a 1 × 106 spores/ml spores suspension, and another three healthy plants were wounded inoculated with mycelial plugs (5 × 5 mm3). Mock inoculations were used as controls with sterile water and PDA plugs on three leaves each. Treated plant tissue were incubated in an artificial climate box at 25°C, 90% relative humidity and a photoperiod of 12 h. After 4 days, symptoms similar to those of natural infection were observed on all wounded inoculated leaves, while no symptoms appeared on mock-inoculated leaves. The fungus isolated from inoculated leaves was identical to the original pathogen based on morphological and molecular data, confirming Koch's hypothesis. It has been reported that C. siamense can cause anthracnose on numerous plants (Rong et al. 2021; Tang et al. 2021; Farr and Rossman 2023). This is the first report of C. siamense causing anthracnose on H. macrophylla in China. The disease is of major concern to the horticultural community as it seriously affects the aesthetic value of ornamentals.

Morphological and Phylogenetic Analyses Reveal Three New Species of Distoseptispora (Distoseptisporaceae, Distoseptisporales) from Yunnan, China.

Three new species of Distoseptispora, viz. D. mengsongensis, D. nabanheensis, and D. sinensis, are described and illustrated from specimens collected on dead branches of unidentified plants in Yunnan Province, China. Phylogenetic analyses of LSU, ITS, and TEF1 sequence data, using maximum-likelihood (ML) and Bayesian inference (BI), reveal the taxonomic placement of D. mengsongensis, D. nabanheensis, and D. sinensis within Distoseptispora. Both morphological observations and molecular phylogenetic analyses supported D. mengsongensis, D. nabanheensis, and D. sinensis as three new taxa. To extend our knowledge of the diversity of Distoseptispora-like taxa, a list of recognized species of Distoseptispora with major morphological features, habitat, host, and locality is also provided.

Improvement of Salinity Tolerance in Water-Saving and Drought-Resistance Rice (WDR).

Rice is one of the most economically important staple food crops in the world. Soil salinization and drought seriously restrict sustainable rice production. Drought aggravates the degree of soil salinization, and, at the same time, increased soil salinity also inhibits water absorption, resulting in physiological drought stress. Salt tolerance in rice is a complex quantitative trait controlled by multiple genes. This review presents and discusses the recent research developments on salt stress impact on rice growth, rice salt tolerance mechanisms, the identification and selection of salt-tolerant rice resources, and strategies to improve rice salt tolerance. In recent years, the increased cultivation of water-saving and drought-resistance rice (WDR) has shown great application potential in alleviating the water resource crisis and ensuring food and ecological security. Here, we present an innovative germplasm selection strategy of salt-tolerant WDR, using a population that is developed by recurrent selection based on dominant genic male sterility. We aim to provide a reference for efficient genetic improvement and germplasm innovation of complex traits (drought and salt tolerance) that can be translated into breeding all economically important cereal crops.

First Report of Corynespora cassiicola Causing Leaf Spot on Jasminum nudiflorum in China.

Winter jasmine (Jasminum nudiflorum Lindl.), a trailing, deciduous shrub, is widely used as an ornamental plant. Its flowers and leaves also has great medicinal value for treatment of inflammatory swelling, purulent eruptions, bruises and traumatic bleeding (Takenaka et al. 2002). In October 2022, leaf spot symptoms were observed on J. nudiflorum distributed in Meiling Scenic Spot (28.78°N, 115.83°E) and Jiangxi Agricultural University (28.75°N, 115.83°E), Nanchang, Jiangxi Province, China. In a week-long series of investigations, the incidences of disease could range up to 25%. Initially, the symptoms of the lesions were small yellow circular spots (0.5 to 1.8 mm), and gradually developing irregular spots (2.8 to 4.0 mm) with grayish white central parts, a dark brown inner ring, and outer yellow halo. To identify the pathogen, sixty symptomatic leaves from fifteen different plants were collected, of which twelve were randomly selected, cut into 4-mm2 pieces, and surface sterilized with 75% ethanol for 30s followed by 5% NaClO for 1 min, rinsed four times with sterile water, and then placed on potato dextrose agar (PDA) medium at 25 °C in the dark for 5 to 7 days. Six isolates with similar morphological characteristics were obtained. Aerial mycelium was vigorous, downy and exhibited white to grayish-green coloration. Conidia were solitary or catenate, pale brown, obclavate to cylindrical, apex obtuse, one to 11 pseudosepta, 24.9 to 125.7 × 7.9 to 12.9 µm (n = 50). Morphological characteristics matched Corynespora cassiicola (Ellis 1971). For molecular identification, two representative isolates (HJAUP C001 and HJAUP C002) were selected for genomic DNA extraction, and the ITS, TUB2 and TEF1-α gene were amplified, using the primer ITS4/ITS5 (White et al. 1990), Bt2a/Bt2b (Lousie and Donaldson 1995) and EF1-728F/EF-986R (Carbone and Kohn 1999), respectively. The sequenced loci (GenBank accession nos. ITS: OP957070, OP957065; TUB2: OP981639, OP981640; TEF1-α: OP981637, OP981638) of the isolates were 100, 99 and 98% similar to the corresponding sequences of C. cassiicola strains (GenBank accession nos. OP593304, MW961419, MW961421, respectively). Phylogenetic analyses of combined ITS and TEF1-α sequences was performed using maximum-likelihood method in MEGA 7.0 (Kuma et al. 2016). The result showed that our isolates (HJAUP C001 and HJAUP C002) clustered with four strains of C. cassiicola at 99% bootstrap values in the bootstrap test (1000 replicates). Based on the morpho-molecular approach, the isolates were identified as C. cassiicola. The pathogenicity of one representative strain (HJAUP C001) was tested by inoculating the wounded leaves of six healthy J. nudiflorum plants under natural condition. Three leaves from each of three plants were punctured with flamed needles and sprayed with a conidial suspension (1 × 106 conidia/ml), and three wounded leaves from each of other three plants were inoculated with mycelial plugs (5 × 5 mm3). Mock inoculations were used as controls with sterile water and PDA plugs on three leaves each, respectively. Leaves from all treatments were incubated in a greenhouse at high relative humidity, 25°C, and 12-hour photoperiod. After one week, all wounded inoculated leaves appeared similar symptoms as described above, whereas the mock inoculated leaves were still healthy. Similar isolates with grayish white and vigorous aerial mycelium were reisolated from inoculated and symptomatic leaves and identified as C. cassiicola by DNA sequencing, fulfilling Koch's postulates. It has been reported that C. cassiicola can cause leaf spots on numerous plant species (Tsai et al. 2015; Lu et al. 2019; Farr and Crossman 2023). However, to our knowledge, this is the first report of C. cassiicola causing leaf spots on J. nudiflorum in China. This finding aids in protection of J. nudiflorum, a medicinal and ornamental plant with high economic value.

Molecular Phylogeny and Morphology Reveal Four Novel Species of Corynespora and Kirschsteiniothelia (Dothideomycetes, Ascomycota) from China: A Checklist for Corynespora Reported Worldwide.

Plant debris are habitats favoring survival and multiplication of various microbial species. During continuing mycological surveys of saprobic microfungi from plant debris in Yunnan Province, China, several Corynespora-like and Dendryphiopsis-like isolates were collected from dead branches of unidentified perennial dicotyledonous plants. Four barcodes, i.e., ITS, LSU, SSU and tef1-α, were amplified and sequenced. Morphological studies and multigene phylogenetic analyses by maximum likelihood and Bayesian inference revealed three new Corynespora species (C. mengsongensis sp. nov., C. nabanheensis sp. nov. and C. yunnanensis sp. nov.) and a new Kirschsteiniothelia species (K. nabanheensis sp. nov.) within Dothideomycetes, Ascomycota. A list of identified and accepted species of Corynespora with major morphological features, host information and locality was compiled. This work improves the knowledge of species diversity of Corynespora and Kirschsteiniothelia in Yunnan Province, China.

Molecular Breeding of Water-Saving and Drought-Resistant Rice for Blast and Bacterial Blight Resistance.

Rice production is often affected by biotic and abiotic stressors. The breeding of resistant cultivars is a cost-cutting and environmentally friendly strategy to maintain a sustainable high production level. An elite water-saving and drought-resistant rice (WDR), Hanhui3, is susceptible to blast and bacterial blight (BB). This study was conducted to introgress three resistance genes (Pi2, xa5, and Xa23) for blast and BB into Hanhui3, using marker-assisted selection (MAS) for the foreground selection and a whole-genome single-nucleotide polymorphism (SNP) array for the background selection. As revealed by the whole-genome SNP array, the recurrent parent genome (RPG) recovery of the improved NIL was 94.2%. The resistance levels to blast and BB of the improved NIL and its derived hybrids were higher than that of the controls. In addition, the improved NIL and its derived hybrids retained the desired agronomic traits from Hanhui3, such as yield. The improved NIL could be useful to enhance resistance against biotic stressors and produce stable grain yields in Oryza sativa subspecies indica rice breeding programs.

Three novel species of Helminthosporium (Massarinaceae, Pleosporales) from China.

Three new species of Helminthosporium, H.nabanhensis, H.sinensis and H.yunnanensis collected on dead branches of unidentified plants in Xishuangbanna, China, were proposed by morphological and molecular phylogenetic analysis. Phylogenetic analysis of the combined data of ITS-SSU-LSU-TEF1-RPB2 sequences was performed using Maximum-Likelihood and Bayesian Inference, although H.nabanhensis and H.sinensis lack the RPB2 sequences. Both molecular analyses and morphological data supported H.nabanhensis, H.sinensis and H.yunnanensis as three independent taxa within the Massarinaceae.

Molecular Breeding of a Novel PTGMS Line of WDR for Broad-Spectrum Resistance to Blast Using Pi9, Pi5, and Pi54 Genes.

BACKGROUND: The two-line method based on the photoperiod and thermo-sensitive genic male sterile (PTGMS) lines is more cost-effective, simple, and efficient than the three-line system based on cytoplasmic male-sterility. Blast and drought are the most prevalent biotic and abiotic stress factors hampering rice production. Molecular techniques demonstrate higher efficacy in the pyramiding of disease resistance genes, providing green performance under the background of water-saving and drought-resistance rice. RESULTS: This study employed molecular marker-assisted selection, conventional hybridization, and high-intensity stress screening to integrate three broad-spectrum blast resistance genes Pi9, Pi5, and Pi54 into Huhan 1S. Subsequently, a novel water-saving and drought-resistance rice (WDR) PTGMS line Huhan 74S was developed. The drought resistance of the new PTGMS line Huhan 74S was comparable to that of Huhan 1S. Pathogenicity assays involving the inoculation of 14 blast prevalent isolates in the glasshouse showed that the blast resistance frequency of Huhan 74S was 85.7%. Further evaluation under natural blast epidemic field conditions showed that Huhan 74S and its hybrids were resistant to leaf and neck blast. The critical temperature point of fertility-sterility alteration of Huhan 74S was 23 °C daily mean temperature. The complete male sterility under natural growth conditions in 2017 at Shanghai lasted for 67 days. Also, both the agronomic and grain quality traits met the requirement for two-line hybrid rice production. CONCLUSION: These results indicate that the newly bred PTGMS line Huhan 74S can be used to breed high-yielding, good-quality, disease-resistant two-line hybrid water-saving and drought-resistance rice (WDR), hence promoting sustainable rice production in China.

Fine mapping a quantitative trait locus, qSER-7, that controls stigma exsertion rate in rice (Oryza sativa L.).

BACKGROUND: Stigma exsertion rate (SER) is a key determinant of outcrossing in hybrid rice seed production. A quantitative trait locus (QTL) for stigma exsertion rate in rice, qSER-7, has previously been detected on chromosome 7 by using a F2 population derived from two indica cytoplasmic male sterility (CMS) maintainers, Huhan 1B and II-32B. RESULTS: The chromosomal location of qSER-7 was precisely delimited by fine-scale mapping. Near-isogenic lines (NILs) were established, one of which isolated the locus in the qSER-7II-32B line, which contains an introgressed segment of II-32B in the Huhan 1B genetic background, and exhibits a significantly higher stigma exsertion rate than that of the recurrent parent. Using 3192 individuals from the BC4F2 segregation population, the QTL qSER-7 was narrowed down to a 28.4-kb region between the markers RM3859 and Indel4373 on chromosome 7. According to the rice genome annotation database, three genes were predicted within the target region. Real-time PCR analysis showed significantly higher expression levels of LOC_Os07g15370 and LOC_Os07g15390 in II-32B than in Huhan 1B. LOC_Os07g15370(OsNRAMP5) was a previously reported gene for Mn and Cd transporter. The stigma exertion rates of OsNRAMP5-overexpressing plants were significantly higher than that of wild type plants, in contrast, a T-DNA insertion mutant osnramp5 showed a lower stigma exertion rate. CONCLUSIONS: In the present study, the QTL qSER-7 was isolated to a region between the markers RM3859 and Indel4373. Two candidate genes were selected based on the expression difference between the two parents, which can facilitate the further cloning of the gene underlying the quantitative trait associated with qSER-7 as well as the marker-assisted transfer of desirable genes for stigma exsertion rate improvement in rice.

Suppressive effects of Momordin Ic on HepG2 cell migration and invasion by regulating MMP-9 and adhesion molecules: Involvement of p38 and JNK pathways.

Momordin Ic was previously found to induce liver cancer cell apoptosis and autophagy. To further elucidate the anti-cancer activity of Momordin Ic, we analyzed the suppressive effects of Momordin Ic on cell migration and invasion. We also investigated the mechanisms associated with MMP-9, adhesion molecules and signaling transductions. The results demonstrated that Momordin Ic effectively prevented cell attachment, migration and invasion. E-cadherin, mediation of homotypic adhesion was induced while VCAM-1 and ICAM-1 and MMP-9 were inhibited. Momordin Ic influenced phosphorylations of p38, JNK and Erk with VEGF. p38 effectively regulated expressions of E-cadherin, VCAM-1 and ICAM-1. JNK greatly contributed to E-cadherin alteration. Erk hardly modified E-cadherin, VCAM-1, ICAM-1 and MMP-9 although Erk phosphorylation decreased by Momordin Ic. These results revealed Momordin Ic prevent cell invasion by inhibiting VCAM-1, ICAM-1, MMP-9 but inducing E-cadherin expression via p38 and JNK pathways. Thus momordin Ic may be a promising candidate with anti-cancer bioactivity.

Enhanced rice salinity tolerance via CRISPR/Cas9-targeted mutagenesis of the OsRR22 gene.

Salinity is one of the most important abiotic stress affecting the world rice production. The cultivation of salinity-tolerant cultivars is the most cost-effective and environmentally friendly approach for salinity control. In recent years, CRISPR/Cas9 systems have been widely used for target-site genome editing; however, their application for the improvement of elite rice cultivars has rarely been reported. Here, we report the improvement of the rice salinity tolerance by engineering a Cas9-OsRR22-gRNA expressing vector, targeting the OsRR22 gene in rice. Nine mutant plants were identified from 14 T0 transgenic plants. Sequencing showed that these plants had six mutation types at the target site, all of which were successfully transmitted to the next generations. Mutant plants without transferred DNA (T-DNA) were obtained via segregation in the T1 generations. Two T2 homozygous mutant lines were further examined for their salinity tolerance and agronomic traits. The results showed that, at the seedling stage, the salinity tolerance of T2 homozygous mutant lines was significantly enhanced compared to wild-type plants. Furthermore, no significantly different agronomic traits were found between T2 homozygous mutant lines and wild-type plants. Our results indicate CRISPR/ Cas9 as a useful approach to enhance the salinity tolerance of rice.

Enhanced saccharide sensing based on simple phenylboronic acid receptor by coupling to Suzuki homocoupling reaction.

Substantially enhanced monosaccharide fluorescent sensing in aqueous solutions using a simple phenylboronic acid receptor is achieved by coupling the classic strategy based on saccharide-boronic acid interaction with catalytic Suzuki homocoupling reaction.

N-(Acetamido)thiourea based simple neutral hydrogen-bonding receptors for anions.

N-(Acetamido)-N'-phenylthioureas (4-6) were found to be efficient anion receptors with higher anion affinity than their N-benzamido-N'-phenylthiourea counterparts (1 and 2). The N'-phenylthiourea moiety in 4-6 was shown to be the chromophore with an absorption maximum at ca. 270 nm. It was found that, in the presence of anions, the absorption at ca. 270 nm of 4-6 (except 5f) in acetonitrile (MeCN) was blue shifted and enhanced while a red-shifted shoulder appeared at ca. 295 nm, together with an isosbestic point at ca. 240 nm. The 1:1 anion binding constants of 4-6, for example at 10(6)-10(7) M(-1) order of magnitude for AcO(-) in MeCN, were found to be higher than those of 1 and 2, although the acidity of the thioureido -NH protons in 4-6 is lower than that in 1 and 2. (1)H NMR data indicates that the N-N single bond in 4-6 is twisted but less than that in 1 and 2. A conformation change at the N-N single bond of 4-6 was suggested to occur upon anion binding which leads to a planar hydrogen-bonding network in the anion binding complex in which a charge transfer takes place with the N-acyl moiety being the electron acceptor. Variations in the CD signals of a proline derivative 6 bearing a chiral center in the N-amido moiety provide direct evidence for this conformation change upon its binding with anions in MeCN. The amplified effect of substituent X at the N'-phenyl ring of 5 on the anion binding constant supports the conclusion of anion-binding switched charge transfer in the anion binding complex. (1)H NMR and absorption titrations for 5 indicated that the anion-receptor interaction was of a hydrogen-bonding nature until the N'-phenyl substituent X is as electron-withdrawing as m-CF(3) (5e). With X being the more electron-withdrawing p-NO(2) (5f), deprotonation of the thioureido -NH occurs in the presence of anion. Results reported here confirm that N-amidothioureas derived from both N-aliphatic and N-aromatic amides can in general be a family of efficient hydrogen-bonding receptors, with the aliphatic N-amido derivatives being more efficient. This provides a wider structural diversity for designing thiourea-based functional molecules such as anion receptors and organocatalysts. Preliminary experiments confirm that 6 could catalyse efficiently the reduction of nitrostyrene in CH(2)Cl(2) and MeCN.