Yan Peng’s research while affiliated with Guizhou University and other places

Adlay (Coix lacryma-jobi L.), a crop closed related to maize (Zea mays L.) and sorghum (Sorghum bicolor L.), originated in tropical/subtropical regions of Asia and Africa; southwest China primary center of this plant’s origin, evolution and migration. Adlay is a traditional high-value minor crop used for both medicinal and dietary purposes. Adlay has anti-tumor, anti-bacterial, anti-inflammatory, analgesic, blood sugar-lowering, and blood lipid-lowering effects. To clarify the main bioactive components and phytochemical compounds and to fully explore their utility, this review summarizes the research done on the main functional ingredients of adlay, including amino acids and proteins, oils, vitamins and minerals, polysaccharides, and polyphenols. This study also highlighted the application of genome sequencing to tailor nutrient-rich adlay cultivars and nutraceutical product development. Additionally, the acquisition of high-density genomic data combined with next-generation phenotypic analysis will undoubtedly improve our understanding of the potential genetic regulation of adlay nutraceutical traits. This review provides new insights and ideas for the research of adlay in comparison and evolutionary genomics, and a useful reference for molecular breeding and genetic improvement of this important minor crop.

We aimed to elucidate the physiological and biochemical mechanism by which exogenous hydrogen peroxide (H2O2) alleviates salt stress toxicity in Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn). Tartary buckwheat “Chuanqiao-2” under 150 mmol·L−1 salt (NaCl) stress was treated with 5 or 10 mmol·L−1 H2O2, and seedling growth, physiology and biochemistry, and related gene expression were studied. Treatment with 5 mmol·L−1 H2O2 significantly increased plant height (PH), fresh and dry weights of shoots (SFWs/SDWs) and roots (RFWs/RDWs), leaf length (LL) and area (LA), and relative water content (LRWC); increased chlorophyll a (Chl a) and b (Chl b) contents; improved fluorescence parameters; enhanced antioxidant enzyme activity and content; and reduced malondialdehyde (MDA) content. Expressions of all stress-related and enzyme-related genes were up-regulated. The F3′H gene (flavonoid synthesis pathway) exhibited similar up-regulation under 10 mmol·L−1 H2O2 treatment. Correlation and principal component analyses showed that 5 mmol·L−1 H2O2 could significantly alleviate the toxic effect of salt stress on Tartary buckwheat. Our results show that exogenous 5 mmol·L−1 H2O2 can alleviate the inhibitory or toxic effects of 150 mmol·L−1 NaCl stress on Tartary buckwheat by promoting growth, enhancing photosynthesis, improving enzymatic reactions, reducing membrane lipid peroxidation, and inducing the expression of related genes.

Oats (Avena sativa L.) are a widely consumed functional cereal grain worldwide and have recently gained increasing attention due to their numerous health benefits. Oats are an excellent natural source of bioactive compounds, including β-glucan, and have broad application prospects for the development of functional foods or health products to prevent and treat of diabetes. In this review, oat bioactive compounds, including proteins, peptides, amino acids, β-glucans, resistant starch, dietary fibers, polyunsaturated fatty acids, vitamins, minerals, polyphenols, avenanthramides, oat saponins, and β-sitosterol are summarized, and their important biological functions are discussed, focusing on the relevant mechanisms of action. Due to their various bioactive ingredients, oats exhibit antioxidant, anti-diabetic, anti-microbial, anti-cancer, anti-hypertensive, immunomodulatory, anti-hyperlipidemic, anti-obesity, and cardioprotective properties.

Soil salinization is one of the main abiotic stress factors impacting the growth of crops and the agricultural industry today. Thus, we aimed to investigate the effects of H2O2 pretreatment on seed germination in Tartary buckwheat (Fagopyrum tataricum) seeds under salt stress and to evaluate this species’ salt tolerance. Through the preliminary experiment, this study used 50 mmol L−1 NaCl solution to induce seed stress. After soaking for 12 h in different H2O2 concentrations, seeds were laid in Petri dishes with 50 mmol L−1 NaCl for seven days and the germination parameters and physiological indicators were measured to screen the optimal H2O2 pretreatment concentration and the salt tolerance index. Our results indicated that pretreatment with 5–10 mmol L−1 H2O2 was most effective in alleviating NaCl’s impacts on the seeds’ germination parameters. Furthermore, the growth and material accumulation of seedlings was promoted; catalase, superoxide dismutase activity, and proline content were enhanced; and malondialdehyde content was reduced. Principal component analysis and stepwise regression revealed six key indicators that had a significant impact on the salt tolerance characteristics of F. tataricum, namely, germination potential, shoot fresh weight, root surface area, root average diameter, catalase activity, and superoxide dismutase activity.

Tartary buckwheat (Fagopyrum tataricum, Polygonaceae) is an annual plant originating in Southwest China. It has a short growth cycle, barren soil tolerance, and strong stress resistance (Zhang et al. 2021). Because of its high content of proteins, starch, trace elements, phenols, and dietary fiber, Tartary buckwheat is beneficial to the human body and hence has received widespread attention (Joshi et al. 2019; Dc ja, B, et al. 2020). In the period from September to November 2020, a diseased plant infected with gray mold was found among M2 generation plants treated using ethyl methanesulfonate (EMS) in a location with potted Tartary buckwheat plants in Huaxi District, Guiyang City, Guizhou Province, China. The diseased plant started to show symptoms during the initial flowering stage; water-soaked spots appeared at first, that the spots increased in size and turned into light brown patches, with the leaf edges scorched brown. In severe cases, the leaves turned yellow, the diseased spots became dry, and finally the leaves necrotic (Figure 1A). Among the leaves that showed disease symptoms, severely susceptible leaves were selected; a piece of tissue (2×2 mm) was removed at the junction of the diseased and healthy tissues. The tissue was then soaked in 75% ethanol for 2 to 3 s, transferred to 1% sodium hypochlorite solution and soaked for 3 min, rinsed three times with sterile water, and placed on sterilized filter paper to dry. Sterile tweezers were used to transfer the tissue blocks to Potato Dextrose Agar medium (Bio-Rad Ltd. Com, USA) containing a Streptomyces–Penicillium mixture (100 μg/mL), and they were incubated on this medium for 7 to 10 days at 25°C and 70% humidity under 16 h light and 8 h dark conditions. The colonies were white at the early stages, with developed aerial hyphae; subsequently, they gradually turned gray-green (Figure 1B). In the later stages, the back of the colony was black and piles of conidia could be seen (Figure 1C). The conidia are scattered, which were colorless and transparent, fusiform or fusiform, with a size of 8.02–11.13 μm×2.06–3.22 μm (average=9.51 μm×2.69 μm, n=50) (Figure 1D). Based on their morphological characteristics, These cultural and morphological characteristics were consistent with the descriptions of as B. dothidea (Fan et al. 2021). The ITS1/ITS4 (Mills et al. 1992), Bt-2a/Bt-2b primers (Glass and Donaldson 1995), and EF1-728F/EF1-986R (Slippers et al. 2004) were amplified and sequenced to analyze the ITS region, β-tubulin genes translation elongation factor 1-α (TEF1-α), and translation elongation factor 1-α (TEF1-α), respectively. According to BLAST search in GenBank, the sequences of ITS (MZ326853), TUB2 (MZ399162) and TEF1-α (MZ399163) had 99.40%, 100% and 100% similarity to sequences NR111146.1, AY236927.1, and AY236898.1 of B. dothidea ex-type strain CMW8000, respectively. The three nucleotide sequences were concatenated together, and MEGA-X (with the neighbor-joining method) with 1,000 bootstraps was used to construct a phylogenetic tree. The results showed that our isolate was closely related to B. dothidea (Figure 2). Healthy Tartary buckwheat from the M2 generation was used for the pathogenicity test. Disinfect with 75% alcohol and 1×105 mL-1 of spore suspension was sprayed on the leaves. Each treatment included three plants, and it was repeated three times with sterile water as control. The treatments were kept in a houseat25°C for 24 h, then transferred it to the natural environment of 22℃ to 28℃,and sterile water was sprayed every morning and evening to keep the leaves moist. After 10 days, the symptoms seen in the field appeared on the treated plants (Figure 1E), but the control plants did not show any symptoms (Figure 1F). The diseased parts of the leaves were isolated and cultured again, and the isolates were consistent with the original inoculum. Thus, the study conformed to Koch’s postulates. B. dothidea is a fungus with no host preference in the genus Botryosphaeria (Botryosphaeriaceae, Botryosphaeriales). It can cause canker, leaf spots, trunk diseases, fruit rot and die-back of many important wood plants all over the world (Marsberg et al.2017). Recently, it was reported that B. dothidea caused soybean canker in China (Chen et al.2021), but there have been no reports of B. dothidea causing Tartary buckwheat gray mold. To the best of our knowledge, this is the first report of B. dothidea causing gray mold on Tartary buckwheat. This finding will provide a basis for the prevention and treatment of Tartary buckwheat gray mold.

Phytopathogenic fungi decrease crop yield and quality and cause huge losses in agricultural production. To prevent the occurrence of crop diseases and insect pests, farmers have to use many synthetic chemical pesticides. The extensive use of these pesticides has resulted in a series of environmental and ecological problems, such as the increase in resistant weed populations, soil compaction, and water pollution, which seriously affect the sustainable development of agriculture. This review discusses the main advances in research on plant-pathogenic fungi in terms of their pathogenic factors such as cell wall-degrading enzymes, toxins, growth regulators, effector proteins, and fungal viruses, as well as their application as biocontrol agents for plant pests, diseases, and weeds. Finally, further studies on plant-pathogenic fungal resources with better biocontrol effects can help find new beneficial microbial resources that can control diseases.