Nervilia plicata is a rare southern Chinese herb. The study on the plant at molecular level is hardly seen. Real-time quantitative PCR (qRT-PCR) has been widely used in plant gene expression analysis, but there is a lack of research on it in N. plicata, which limits the progress of related work. Based on the previous researches, nine candidate reference genes, including Actin, GAPDH, TUA, UBC, UBQ, EF-1α, EF-1β, CYP and RPL, were screened out from the transcriptomic sequencing data. In order to select suitable reference gene in N. plicata, qRT-PCR technique was employed to detect the expression levels of the candidate reference genes in leaf, petiole and corm tissues of the plant. After analyzing the expression levels, the stability and comprehensive analysis of nine genes in different tissues, the most suitable reference gene was obtained. Finally, the most suitable reference gene was validated using NpDFR, Np3GT that related to anthocyanin synthesis. Results showed that the expression stability of EF-1 α and CYP was similar, with the best overall stability. When using either EF-1α or CYP, or the combination of them, as reference, the expression patterns of NpDFR and Np3GT in different tissues were consistent with the transcriptome sequencing results. This indicates that both EF-1 α and CYP can be used as reference genes in N. plicata for qRT-PCR. This study would provide a basis for further research on the molecular mechanism of genes related to the pharmacological effects of N. plicata.

Knowledge on germplasm resource information is the foundation for the genetic improvement of Aquilaria sinensis, and genome resequencing is a powerful tool for analyzing the genetic diversity of germplasm resources. However, there is no research on the genetic diversity of A. sinensis using genome resequencing. Based on the collection of A. sinensis germplasm resources in the early stages, this study utilized genome resequencing to obtain 1284 Gb of resequencing data from 60 samples of A. sinensis. Using the agarwood genome, 6 716 166 high-quality variation sites were detected, including 6 284 344 SNP sites and 428 658 Indel sites. Principal component analysis, phylogenetic analysis, and genetic structure analysis all indicated that A. sinensis could be divided into three distinct groups (Pop1, Pop2 and Pop3), with two of the groups further subdivided into multiple subgroups. Population selection signals were detected in all the groups, with Pop3 showing the highest frequency of selection signals. However, nucleotide polymorphism calculations indicated that Pop3 had the lowest nucleotide polymorphism. This study would provide valuable information for exploring the genetic resource diversity of A. sinensis and lay a theoretical foundation for genome-based genetic breeding of A. sinensis.

Phosphorus is one of the essential nutrients for plant growth, and plays a crucial role in determining crop yield and quality. Due to the combined pressure of decreased arable land quality and soil phosphorus deficiency or low bioavailability, the improvement of soil phosphorus availability has become a global concern. The rotation of two or more crops has positive effects on soil improvement, crop production efficiency and the restoration of agricultural ecosystem function. This study reviews the research progress on the effects of crop rotation on soil physiochemical properties, soil phosphorus transformation, and soil micro-food web. Firstly, the relationship between soil properties and phosphorus transformation is analyzed to assess the impact of crop rotation on phosphorus availability. Secondly, from the perspective of soil micro-food web and gene regulation, the transformation and biogeochemistry cycle of soil phosphorus was analyzed at the molecular level. It is summarized that crop rotation can affect soil phosphorus transformation through altering soil physiochemical properties and micro-food network structure, which can improve soil phosphorus availability, and ultimately promote crop yield and quality. We indicate that crop rotation is an important agricultural management measure for improving soil phosphorus availability. It is suggested to strengthen the related research and explore the combination model of crop rotation in the future. It would provide powerful support for food security and crop quality, and is of great significance in social economy and ecological environment.

Papaya ringspot virus (PRSV) is one of the most serious diseases in papaya production, with high incidence rate, rapid transmission and serious harm. To detect papaya plants infected with PRSV in a timely manner, this study established methods for detecting papaya plants infected with PRSV using enzyme-linked immunosorbent assay (ELISA) and fluorescence quantitative reverse transcription PCR (qRT-PCR). The two methods were used to detect the PRSV content of multiple transgenic and non transgenic papaya plants, and the results were compared. The results showed that the standard curve established using PRSV peptide antigen as the standard and antibodies prepared from it had good fitting, and could be used for ELISA detection of PRSV; The reference gene Cpa03g018830 selected in qRT-PCR method was stably expressed at different growth stages of papaya and could be used as a reference gene for PRSV content determination; The detection results of PRSV content in multiple transgenic and non transgenic papaya plants using ELISA and qRT-PCR methods were basically consistent, indicating that both methods can be used for the detection of PRSV content in papaya plants. By using thee two detection methods, papaya plants infected with PRSV can be detected and eradicated in a timely manner, effectively preventing and controlling the spread of PRSV.

Lysophosphatidyl acyltransferase (LPAT), a key enzyme which controls the production of lysophosphatidic into phosphatidic, plays an important role in phospholipid biosynthesis in plants. Hevea brasiliensis is an important source for the production of natural rubber, which has an irreplaceable role in the fields of national defense, medical treatment, high-end products, and has high social and economic value. Cloning and analysis of HbLPAT2 in H. brasiliensis would provide scientific basis for further exploration of its phospholipid biosynthesis function and the effect of phospholipid on nature rubber. In this study HbLPAT2 was cloned from the latex of the H. brasiliensis by molecular biology techniques, and the bioinformatics analysis, expression analysis and subcellular localization analysis were performed. In this study, two key genes responsible for phospholipid biosynthesis in the HbLPAT gene family were successfully cloned from the latex of the H. brasiliensis, named HbLPAT2a and HbLPAT2b, the full length coding sequence of HbLPAT2a and HbLPAT2b genes was 1161 bp and 939 bp, encoding 386 and 312 amino acids. Both HbLPAT2a and HbLPAT2b contained a PLN02380 lysopyatidyl acyltransferase functional domain and contained a highly conserved NH(X)₄D motif; HbLPAT2a protein had 3 transmembrane domains, and HbLPAT2b protein had 1 transmembrane domain, both of which had no signal peptide, were hydrophilic proteins, and contained multiple phosphorylation sites. The subcellular localization analysis showed that both HbLPAT2a and HbLPAT2b proteins were located in the endoplasmic reticulum. In different organs, the highest expression level of HbLPAT2a and HbLPAT2b was found in seeds, suggesting that they have a lipid biosynthesis function. However, in the latex of H. brasiliensis, the first and second expression level of whole HbLPAT gene family were HbLPAT2a and HbLPA2b. The result is helpful to understanding that HbLPAT2a and HbLPAT2b play an important role in the phospholipid biosynthetic pathway in latex of H. brasiliensis and to providing a scientific basis for genetic improvement of latex quality of H. brasiliensis.

Plant peroxidase (POD) plays a role in plant development, hormone signaling, and stress response, but there are few research reports on the POD gene in mango. This study used mango genome data as a reference and employed bioinformatics methods to identify members of the POD gene family from multiple aspects, including protein characteristics, phylogenetic relationships, gene structure, promoter cis acting elements, and gene expression patterns. The expression patterns of POD gene family members under enhanced UV-B irradiation through transcriptome and quantitative real-time PCR (qPCR) experiments were analyzed. The mango POD (MiPOD) gene family had a total of 77 family members, and the genes were then mapped to 17 chromosomes and 2 scaffolds, encoding amino acids with a number of 206~500 aa, Stable proteins were accountted for the majority, most of them were hydrophilic proteins. Most MiPOD were predicted to localize in subcellular within chloroplasts, and classified into seven subgroups using phylogenetic analysis. The gene structure among members of the subgroup were similar. The results of collinearity analysis indicated that the proportion of MiPOD genes involved in segmental duplication was relatively high. It was speculated that it may be related to the expansion of the MiPOD family. The selection pressure analysis indicated that the K_a/K_s values of collinear genes were far less than 1, indicating that MiPODs may be mainly subjected to purifying selection during the evolutionary process. The MiPODs promoter region contained a large number of light responsive, hormone responsive, and stress responsive elements. MiPOD had different expression patterns, which may be related to its different protein functions. MiPOD exhibited different expression patterns during fruit growth and development under enhanced UV-B irradiation, with only MiPOD7 showing significant differences in expression levels among the highly expressed members. MiPOD7 expression levels were significantly higher than those of the control under UV-B stress, suggesting that it may play an important role in the response of mango fruit to UV-B stress. In summary, members of the MiPOD gene family may have evolved through segmental duplication and intron reduction patterns, and perform different functions by sensing different types of signals, thus forming different expression patterns. This research would lay the foundation for further studying the response mechanism of mango POD genes to different signals.

As an imported crop, date palm lacks planting management experience in China. It is imperative for the development of Chinese date palm industry to select suitable nutrients, construct the date palm rooting system quickly and efficiently, ensure the full absorption of nutrients by the roots during the field planting period, and shorten the growth cycle of date palm. In order to study the effects of different microalgae fertilizer on the growth of date palm seedlings of “Mabroom” and “Sillege” varieties, fresh microalgae (M₁), fermented microalgae solution (M₂), microalgae nutrient solution (M₃) and microalgae circulation solution (M₄) were selected to treat the seedlings. The growth and physiological indexes (leaf length, relative permeability of cell membrane, malondialdehyde MDA, peroxidase POD, catalase CAT, glutathione reductase GR) of date palm seedlings were measured. The results showed that the leaf length of “Mabroom” seedlings was significantly higher than that of the control group after treatment with microalgae nutrient solution (M₃) and microalgae circulation solution (M₄), and the microalgae nutrient solution (M₃) and microalgae circulation solution (M₄) could promote the growth of “Mabroom” seedlings. The osmotic regulation ability of leaf cells was strong. The contents of catalase, peroxidase and malondialdehyde were lower than those of the control. After treatment with fresh microalgae (M₁) and fermented microalgae solution (M₂), the leaf elongation length of “Sillege” seedlings was significantly higher than that of the control, and fresh microalgae (M₁) and fermented microalgae solution (M₂) were more suitable for the growth of “Sillege” seedlings, with fresh microalgae (M₁)>fermented microalgae solution (M₂). The osmotic regulation ability of leaf cells was higher than that of the control. The change of catalase content was lower than that of the control. This study showed that during the cultivation of microalgae, the microalgae nutrient solution (M₃) and microalgae circulation solution (M₄) could synthesize related active substances to produce primary metabolites. Such bioactive substances were absorbed by seedling roots and promoted the elongation and growth of date palm leaves. The “Mabroom” seedlings were more suitable to apply the secondary metabolites of microalgae as fertilizer. “Sillege” date palm seedlings are more suitable for fresh and fermented microalgae.

Grapefruit of Guipuyou No. 1 planted in Guangxi has high and stable yield, and the flesh is juicy, suitably acidic and sweet. The widely targeted metabolisms of flesh was determined, the differential metabolites were screened and the metabolic pathway was analyzed to understand the difference of flesh composition at different maturity stages. A total of 529 metabolites were detected from grapefruit of Guipuyou No. 1, including 159 flavonoids, 64 Phenolic acids,64 amino acids and derivatives, 53 others (saccharides and alcohols, vitamin, others), 51 lipids, 40 lignans and coumarins,34 nucleotides and derivatives, 29 alkaloids, 28 organic acids, 5 terpenoids and 2 tannins. The differential metabolites at different maturity stages mainly included flavonoids, phenolic acids, amino acids and their derivatives, lipids, lignans and coumarins, and most of them were down-regulated. The down-regulated types of phenolic acids, amino acids and their derivatives, lipids and other types increased, and most of them showed a continuous downward trend with the increase of fruit ripeness. Most of the down-regulated flavonoids showed a sharp decline in the early stage of fruit ripening, and then increased in the late stage of fruit ripening. The types of down-regulated flavonoids first increased and then decreased, with the most in the middle stage of fruit ripening. The relative contents of synephrine, spermidine, betaine, shikimic acid were consistently decreasing. The relative content of limonin increased in the early stage of fruit ripening, and decreased significantly in the middle and late stage of fruit ripening. The most significant enrichment pathway of differential metabolites was flavonoid biosynthesis in the early stage of fruit ripening, but it was phenylpropanoid biosynthesis during the whole ripening process. The fruit of G₂ had the best taste, with soluble solids of 12% and solid-acid ratio of 23.24, which was suitable for fresh eating. However, phenolic acids such as caffeic acid and ferulic acid, flavonoids such as isoquercitrin and hyperoside decreased significantly during this period. There were many kinds of metabolites in the pulp of grapefruit of Guipuyou No. 1, which was rich in nutritional and functional components. The best picking time for fresh food is from late October to middle November. Fruits used for health care or medicinal purposes should be picked in advance according to the efficacy requirements. This study would provide a theoretical basis for the study on the nutritional and functional components of grapefruit of Guipuyou No.1, and provide a reference for the best harvest maturity of its different uses.

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.

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.