Mikania micrantha is one of the first invasive species in China, which poses a big threat to the ecological security of subtropical regions. Soil enzyme activity inhibitors and plant growth regulators play central roles in plant growth regulation. In this paper, the effects of different concentrations of soil enzyme activity inhibitors [1 g/L and 15 g/L NBPT, N-(N-butyl) thiophosphate triamide, 1 g/L and 15 g/L nitrification inhibitor DMPP] and exogenous plant regulators (25 mg/L and 50 mg/L ABA, abscisic acid, 1 g/L and 10 g/L CCC, chlormequat) on the growth of M. micrantha during its vigorous growth period, budding period, flowering period, peak flowering period, and seed setting period were studied through a 7-month continuous pot culture experiment. The results showed that high and low concentrations of soil enzyme activity inhibitors and plant growth regulators had different effects on the growth status of chamomile and the content of alkaline hydrolyzed nitrogen and available phosphorus in the soil. Among them, chloramphenicol and DMPP had a significant inhibitory effect on chamomile, while 15 g/L NBPT had a promoting effect on chamomile growth. In summary, 10 g/L chloramphenicol had an inhibitory effect on the vigorous growth of chamomile, while 15 g/L DMPP had an inhibitory effect on the vigorous flowering period of chamomile. The combined application of the two could provide a theoretical basis for the comprehensive prevention and control of chamomile throughout its lifecycle.

In order to provide technical support for risk management, risk analysis and risk assessment of pests carried by citrus seedlings in China were carried out. Through consulting domestic and foreign literature, a total of 259 species of pests that may be transmitted to banana seedlings exported to China were determined, including 53 fungus, 9 bacteria,9 viruses, 11 nematodes, 167 insects, 1 mollusc, 1 weed, 8 mites (including spiders). According to the distribution of pests in China (not distributed or not widely distributed), whether it is officially controlled, and the possibility of carrying with banana seedlings, 18 potential quarantine pests were determined to be further evaluated, including 4 fungus, 7 bacteria, 4 viruses, 2 nematodes and 1 insect. The 18 potential quarantine pests were qualitatively and quantitatively analyzed one by one in terms of entry, colonization, possibility of spread, economic impact and comprehensive evaluation of multiple indicators, and 14 high-risk pests and 4 extremely high-risk pests were identified. The quarantine risk of citrus seedlings imported to China was determined to be extremely high based on the highest risk level among all quarantine pests. Finally, 18 types pests including Bisifusarium dimeru on citrus seedlings imported to China were identified, and corresponding risk management measures were proposed.

In order to enhance the antifungal activity of Streptomyces samsunensis 17-7 strain and effectively utilize its secondary metabolites, this study focused on optimizing the fermentation medium formula. Orthogonal and single factor experiments were conducted based on the original medium, with Phellinus noxious as the indicator. The optimal formulation for producing active substances from the strain was determined to include 25 g/L soy powder, 10 g/L corn meal,10 g/L glucose, 2 g/L yeast extract, 1 g/L K₂HPO₄, 0.5 g/L NaCl, and 0.5 g/L CaCO₃. Following a 500 times dilution, the relative antifungal activity of the fermentation solution increased to 51.37%, a 17.66% improvement compared to the previous optimization, demonstrating a broad spectrum of antifungal activity. The stability of the antifungal substance was evaluated in response to various conditions such as temperature, pH, protease, UV-irradiation, and storage. Results indicated that the fermentation broth of strain 17-7 exhibited high temperature resistance, a significant decrease in antifungal activity after one hour of UV irradiation, but retained its activity after long-term exposure to UV light. Furthermore, the broth demonstrated good acid-base tolerance, effective antibacterial activity in the pH range of 3-10, and resistance to trypsin and pepsin. The fermentation broth of strain 17-7 maintained its antifungal activity for 120 days at both 4 ℃ and room temperature (25 ℃). This study on the stability and storage conditions of strain 17-7’s fermentation broth offers valuable data for potential future applications of the strain as a biocontrol agent.

The biological macromolecules such as polysaccharides and terpenes in Sanghuangporus spp. aqueous extract have inhibitory effects on tumor cells, but the function was not yet clear. This study obtained small molecule compounds of Sanghuangporus sanghuang Sheng H. Wu, L. W. Zhou & Y. C. Dai and Phellinus baumii aqueous extracts through 3000 D ultrafiltration, and studied the inhibitory activities on mouse hepatocarcinoma cells Hepa 1-6 using dual fluorescence labeling. The anticancer active ingredients were analyzed using metabolomics analysis. The results showed that the small molecule compounds of S. sanghuang Sheng H. Wu and P. baumii could induce injury and apoptosis of Hepa 1-6, with inhibition rates of (38.64±4.35)% and (32.52±3.57)%, respectively. Meanwhile, the inhibition rates of small molecule compounds reached (77.27±6.21)% and (76.92±5.45)%, respectively, after mixing with crude polysaccharides. Metabolomic analysis showed that anti-cancer small molecular agents such as ellipticine, betonicine, cerebroside-B etc., were identified in the aqueous extract of Sanghuangporus spp. Antitumor related substances such as heterocyclic compounds (6-fluoroindole, 2,4,6-trimethylpyridine, 1'-naphthoyl-2-methylindole, etc.), nucleoside and bases (1-methyladenosine, N6-methyladenosine, 2'-O-methyladenosine, etc.), dipeptides (leucine+*, isoleucine+*, γ-glutamine+*, etc.), sugar alcohols (xylitol, ribose, mannitol, erythritol, etc.), were identified too. The results indicate that the aqueous extract of Sanghuangporus spp. contains multiple small molecular agents against tumor cells, which have a synergistic anti-cancer effect with biological macromolecules such as polysaccharides. This would provide a scientific basis for understanding the mechanism of anti-tumor of Sanghuangporus spp. and the development and application of functional substances.

The bottom fraction of the latex from the Brazilian rubber tree (Hevea brasiliensis), specifically the biological membranes that includes lutoids and the Frey-Wyssling complex, may undergo changes in its membrane lipids and membrane proteins. The changes could affect the coagulation rate of the latex during the tapping process and the speed of blockage of the incision of the latex vessels, thereby preventing the flow of latex and reducing yield. Two types of rubber trees with rapid and normal coagulation rates of latex were selected. Liquid chromatography-mass spectrometry technology (with both positive and negative ion detection modes) was used to qualitatively and quantitatively analyze the lipids in the bottom fraction of the two types of latex, obtaining information on differential lipids. In the bottom fraction of the latex from trees with normal coagulation rates, phosphatidylethanolamine was the most abundant phospholipid subclass (accounting for about 22% of total lipids in negative ion mode and about 5.9% in positive ion mode); it was greater than phosphatidylcholine (about 12% in positive ion mode and about 4% in negative ion mode); phosphatidic acid had a high abundance (about 4% in positive ion mode and about 12% in negative ion mode), comparable to phosphatidylcholine; cardiolipin was abundant in the bottom fraction (about 6% in negative ion mode) and may be present in the Frey-Wyssling complex. In the rubber trees prone to rapid coagulation, cardiolipin in the bottom fraction significantly decreased to about 3.4% in negative ion mode. The phospholipids in the bottom fraction accounted for 31%-56%, neutral lipids 35%-54%, and glycolipids only 1%-2%. The bottom fraction contained a high abundance and quantity of non-bilayer phospholipids, namely phosphatidylethanolamine, phosphatidic acid, and cardiolipin, showing a highly dynamic nature of the latex bottom fraction. The significant downregulation of cardiolipin in the latex prone to rapid coagulation may affect the stability of the bottom fraction, thereby affecting latex coagulation, laticifer blockage, and latex flow. The discovery of high abundant non-bilayer phospholipids in bottom fraction in this study introduces a new perspective into the research of latex coagulation and laticifer blockage mechanisms.

Starch sodium octenyl succinate is a food additive produced by the process of esterification using starch and octenyl succinic anhydride. In this study, the tapioca starch sodium octenyl succinate was prepared and characterized with non-alcohol esterification by substituting the organic reagent-dispersed OSA with the OSA emulsification technique. The results showed that OSA emulsion prepared with soybean phospholipid (SP) as an emulsifier had good stability and dispersibility. The octenyl succinic acid group content, degree of substitution, and substitution efficiency of 1.00% SP-SSOS made using OSA emulsions with 1.00% SP emulsifiers were found to be greater compared to IPA-SSOS made using isopropanol-dispersed OSA. FT-IR showed that 1.00% SP-SSOS and IPA-SSOS had two new characteristic peaks at 1572 cm^–1 and 1726 cm^–1, with 1.00% SP-SSOS having a stronger peak intensity. Confocal laser scanning microscopy confirmed that the fluorescence intensity of the fluorescence-labeled OS group was slightly stronger in 1.00% SP-SSOS, and a few starch particles contained OS groups inside. The results indicated that the use of high-pressure homogenization and emulsifiers to disperse OSA into micron-sized oily droplets for esterification could increase the contact area between OSA and starch, improving the efficiency of the esterification reaction. To summarize, it is possible to produce SSOS by utilizing the OSA emulsification technique as an alternative to organic reagents for dispersing OSA. This study would provide a reference for the application of an alcohol-free esterification reaction system in the large-scale industrial production of SSOS.

Coconut oil residue (COR) and coconut milk residue (CMR) are the two main by-products of coconut meat, which are produced during the processing of coconut oil and coconut milk, respectively. In order to explore the processing suitability of the two by-products, the nutritional and physicochemical properties of the two by-products were comprehensively analyzed. The results showed that the fat content of COR (19.37 g/100 g) was lower than that of CMR, while the nutrients such as protein (11.32 g/100 g), total dietary fiber (63.92 g/100 g), soluble dietary fiber (4.42 g/100 g), polysaccharides (25.67 mg/g), flavonoids (4.21 mg/g), total phenols (1.15 mg/g) and other active ingredients were higher than those of CMR. The hydrolyzed amino acids of COR and CMR were similar, but the content was significantly different, which was 94.955 mg/g and 56.975 mg/g, respectively. COR showed better hydration properties nificantly different, which was 94.955 mg/g and 56.975 mg/g, respectively. COR showed better hydration properties than CMR at different temperatures, but the fluidity of both was poor. COR had relatively higher thermal stability, more complete crystal structure and higher group activity than CMR. In conclusion, compared with CMR, COR has more nutrients and active ingredients, hydration properties and fluidity, and has higher thermal stability and stable crystal structure, which is an ideal raw material for low-fat, low-sugar and high-fiber food processing. The results of this study could provide theoretical guidance for the high-value utilization of coconut meat processing by-products in the food industry.

Phytochelatin synthase (PCS) is a key enzyme that catalyzes the synthesis of phytochelatin (PC). PC can reduce the toxicity of heavy metals to plants through complexation. Heavy metal pollution in soil increases the risk of cassava food safety. It is of great significance to study the reduction and control of heavy metals in cassava by analyzing the function of MePCS1 gene. In this study, the coding region of MePCS1 gene in cassava variety SC8 was cloned by PCR. The full length was 1512 bp, encoding 503 amino acids. Protein sequence analysis showed that MePCS1 protein was a hydrophilic protein, containing 41 phosphorylation sites and 2 glycosylation sites, without signal peptide. The phylogenetic tree showed that the cassava MePCS1 protein had the closest relationship with the PCS protein of the rubber tree. The qPCR analysis showed that the MePCS1 gene had the highest expression level in the stem. During the development of cassava roots, the expression level of MePCS1 gene was the highest in the root enlargement period. Lead (Pb) stress induced MePCS1 gene expression. MePCS1 gene can improve the tolerance of BY4741 yeast to Pb. The results of this study provide new information for further analysis of the functional characteristics of the MePCS1 gene and its mechanism for reducing Pb in cassava tuber roots.

Cassava (Manihot esclenta Crantz) has excellent planting characteristics such as drought resistance, barren tolerance and strong adaptability, and is the main food crop for more than 1 billion people in the world. CMLs (calmodulin-like proteins) are plant calmodulin-like receptors in cells. They interact with other calmodulin-binding proteins to regulate cellular physiological processes and participate in plant stress response. MeCML42 gene in cassava is induced by drought stress. In order to study the drought stress response pathway involved in this gene, yeast two-hybridization was used to screen the interacting proteins of MeCML42. Firstly, the decoy vector pGBKT7-MeCML42 was constructed by homologous recombination technique, and the self-activation experiment showed that MeCML42 protein had no self-activation activity. The toxicity test showed that MeCML42 protein was not toxic to yeast and did not affect the normal growth of yeast. The cDNA library was screened by yeast two-hybridization and 7 candidate interacting proteins were obtained. The interaction between MeCML42 and thioredoxin MeCDSP32 was verified by yeast double heterogyclic experiment. Mannitol simulation of drought stress showed that the expressions of MeCML42 and MeCDSP32 were both induced by drought, and the expression levels were the highest at 48 h under stress. These results indicated that MeCML42 and MeCDSP32 were synergistically involved in cassava's response to drought stress. The results of this study provide a new basis for MeCML42 to participate in cassava response to drought stress.

The level of cyanogenic glucosides content is an important trait for the edible quality of cassava, and Me-CYP79D2 is one of the key enzyme genes regulating cassava cyanogenic glucosides synthesis. This study used the edible variety SC9 as the material, cloned the MeCYP79D2 gene in the cytochrome P450 enzyme family of cassava, analyzed it using bioinformatics software, and detected its expression characteristics in different cassava germplasm tubers using real-time quantitative PCR. The cyanogenic glucosides content was measured using HPLC, and its correlation with the expression level of MeCYP79D2 gene was analyzed. The results showed that the length of the coding region sequence of MeCYP79D2 gene was 1625 bp, encoding 528 amino acids. It belonged to an unstable lipophilic hydrophilic protein with 38 phosphorylation sites. Sequence alignment indicated that the gene was highly conserved, and phylogenetic analysis showed that MeCYP79D2 was closely related to rubber and leprosy trees. There was a significant positive correlation between the expression of MeCYPD2 gene and the content of cyanogen glycosides in cassava roots of germplasms with different levels of cyanogen glycosides. After treatment with methyl jasmonate, the expression of MeCYP79D2 gene in roots was significantly upregulated and the content of cyanogenic glucosides was significantly increased. The results of this study indicates that MeCYP79D2 is involved in cyanogenic glucosides synthesis, providing a theoretical basis for studying the molecular mechanism of cassava cyanogenic glucosides biosynthesis.