Yuanyuan Li

Protected cultivation, as a core model of modern agriculture, holds a crucial strategic position in alleviating the shortage of arable land resources and increasing farmers’ income. However, due to the closed environment of protected cultivation, suitable temperature and humidity conditions for pathogen reproduction, serious continuous cropping obstacles, disease transmission easily caused by irrigation, and the lack of natural ultraviolet inhibition and crop rotation conditions, soil-borne pathogens accumulate year by year, resulting in early onset, rapid spread, and great difficulty in control. Traditional pesticide formulations often have limitations such as environmental hazards, low utilization rate, unstable active ingredients, excessive use, and short persistence in the control process. In recent years, pesticide slow-release carriers developed based on nanotechnology to regulate the slow-release behavior of pesticide active ingredients have shown great potential in improving pesticide efficacy and safety. This article reviews several commonly used materials for mineral carriers, metal oxide carriers, organic polymer carriers, and organic–inorganic hybrid carriers. With their high specific surface area, high drug loading rate, environmental friendliness, and stimulus-responsive properties, these materials can significantly improve the effective utilization rate of pesticides, extend the persistence period, and enhance targeting, thus providing strong technical support for solving the problem of soil-borne disease control in protected cultivation and promoting the green and sustainable development of protected cultivation.

Background: Changes in gene expression in plant hybrids are closely related to heterosis. Currently, few reports on key genes that promote yield advantage formation in Chinese cabbage hybrids exist.Methods: We conducted a comparative transcriptomic analysis between a Chinese cabbage hybrid (weichunbaiNo.3) and its parents using RNA sequencing, and the differentially expressed genes between the Chinese cabbage hybrid and its parents were confirmed in the rosette and the mature stages. The expression patterns of the differentially expressed genes were examined. The weighted gene coexpression network analysis and virus-induced gene silencing technology were employed to assess the key gene function in yield advantage formation of the Chinese cabbage hybrid.Results: In total, 3652 and 2768 genes were differentially expressed between the Chinese cabbage hybrid and its parents in the rosette and mature stages, respectively. These differentially expressed genes among the hybrid and its parents presented diverse expression patterns, and the expression levels of the most differentially expressed genes in the hybrid were higher than one of the parents but lower than another. The horticultural characteristics showed that weichunbai No. 3 hybrid had a greater yield advantage compared with parents. A vital hub gene related to yield, BraA09g035160.3C (an LHCB1 gene), was identified by weighted gene coexpression network analysis. Through virus-induced gene silencing technology, the expression level of the BraA09g035160.3C gene in the hybrid was dramatically decreased, which slowed hybrid growth.Discussion: BraA09g035160.3C gene could play an important regulatory role in the yield advantage formation of weichunbai No. 3. These results will provide an important reference for in-depth research on the molecular mechanism underlying the yield advantage formation of Chinese cabbage hybrids.

The hollowness phenomenon of radish (Raphanus sativus L.) root is very easy to occur during the storage, which seriously affects its quality. “Weixian radish” was used as the test material, and metabolomics technology and multivariate statistical analysis were employed to explore the underlying mechanism. The results revealed 384 differential metabolites in VL0 vs VL1 (174 up-regulated, 210 down-regulated), 440 differential metabolites in VL0 vs VL4 (279 up-regulated, 161 down-regulated), and 298 differential metabolites in VL1 vs VL4 (226 up-regulated, 72 down-regulated). The KEGG enrichment analysis indicated that a total of four metabolic pathways were significantly enriched in the process of radish hollowness. Notably, only cysteine and methionine metabolism was significantly enriched in the comparisons of VL0 vs VL1 and VL0 vs VL4 positive ions. Therefore, the cysteine and methionine metabolism could be the most critical metabolic pathway involved in the response of radish taproots to the hollowness phenomenon. The study suggested that a decrease in homocysteine content may lead to reducing glutathione levels, impacting the antioxidant capacity of radish taproots. In conclusion, hollowness may indirectly influence the anabolism of glucosinolates in radish taproots by affecting the metabolism of cysteine and methionine, as well as the biosynthetic pathways of phenylalanine, tyrosine, and tryptophan, thereby impacting the antioxidant capacity of radish taproots.

A series of hybrid hydrogels of poly(ethylene glycol) (PEG) were synthesized using gelatin as a crosslinker and investigated for controlled delivery of the first-generation cephalosporin antibiotic, Cefazedone sodium (CFD). A commercially available 4-arm-PEG–OH was first modified to obtain four-arm-PEG–succinimidyl glutarate (4-arm-PEG–SG), which formed the gelatin–PEG composite hydrogels (S_nN_m) through crosslinking with gelatin. To regulate the drug delivery, S_nN_m hydrogels with various solid contents and crosslinking degrees were prepared. The effect of solid contents and crosslinking degrees on the thermal, mechanical, swelling, degradation, and drug release properties of the hydrogels were intensively investigated. The results revealed that increasing the crosslinking degree and solid content of S_nN_m could not only enhance the thermal stability, swelling ratio (SR), and compression resistance capacity of S_nN_m but also prolong the degradation and drug release times. The release kinetics of the S_nN_m hydrogels were found to follow the first-order model, suggesting that the transport rate of CFD within the matrix of hydrogels is proportional to the concentration of the drug where it is located. Specifically, S₁N₁-III showed 90% mass loss after 60 h of degradation and a sustained release duration of 72 h. The cytotoxicity assay using the MTT method revealed that cell viability rates of S₁N₁ were higher than 95%, indicating excellent cytocompatibility. This study offers new insights and methodologies for the development of hydrogels as biomedical composite materials.

Background: Green-fleshed radish (Raphanus sativus L.) is an economically important root vegetable of the Brassicaceae family, and chlorophyll accumulates in its root tissues. It was reported that the basic helix-loop-helix (bHLH) transcription factors play vital roles in the process of chlorophyll metabolism. Nevertheless, a comprehensive study on the bHLH gene family has not been performed in Raphanus sativus L. Results: In this study, a total of 213 Raphanus sativus L. bHLH (RsbHLH) genes were screened in the radish genome, which were grouped into 22 subfamilies. 204 RsbHLH genes were unevenly distributed on nine chromosomes, and nine RsbHLH genes were located on the scaffolds. Gene structure analysis showed that 25 RsbHLH genes were intron-less. Collineation analysis revealed the syntenic orthologous bHLH gene pairs between radish and Arabidopsis thaliana/Brassica rapa/Brassica oleracea. 162 RsbHLH genes were duplicated and retained from the whole genome duplication event, indicating that the whole genome duplication contributed to the expansion of the RsbHLH gene family. RNA-seq results revealed that RsbHLH genes had a variety of expression patterns at five development stages of green-fleshed radish and white-fleshed radish. In addition, the weighted gene co-expression network analysis confirmed four RsbHLH genes closely related to chlorophyll content. Conclusions: A total of 213 RsbHLH genes were identified, and we systematically analyzed their gene structure, evolutionary and collineation relationships, conserved motifs, gene duplication, cis-regulatory elements and expression patterns. Finally, four bHLH genes closely involved in chlorophyll content were identified, which may be associated with the photosynthesis of the green-fleshed radish. The current study would provide valuable information for further functional exploration of RsbHLH genes, and facilitate clarifying the molecular mechanism underlying photosynthesis process in green-fleshed radish.

The flesh of the taproot ofRaphanus sativusL. is rich in chlorophyll (Chl) throughout the developmental process, which is why the flesh is green. However, little is known about which genes are associated with Chl accumulation in this non-foliar, internal green tissue and whether the green flesh can perform photosynthesis. To determine these aspects, we measured the Chl content, examined Chl fluorescence, and carried out comparative transcriptome analyses of taproot flesh between green-fleshed “Cuishuai” and white-fleshed “Zhedachang” across five developmental stages. Numerous genes involved in the Chl metabolic pathway were identified. It was found that Chl accumulation in radish green flesh may be due to the low expression of Chl degradation genes and high expression of Chl biosynthesis genes, especially those associated with Part Ⅳ (from Protoporphyrin Ⅸ to Chl a). Bioinformatics analysis revealed that differentially expressed genes between “Cuishuai” and “Zhedachang” were significantly enriched in photosynthesis-related pathways, such as photosynthesis, antenna proteins, porphyrin and Chl metabolism, carbon fixation, and photorespiration. Twenty-five genes involved in the Calvin cycle were highly expressed in “Cuishuai”. These findings suggested that photosynthesis occurred in the radish green flesh, which was also supported by the results of Chl fluorescence. Our study provides transcriptome data on radish taproots and provides new information on the formation and function of radish green flesh.