Involvement of glucosinolates and phenolics in the promotion of broccoli seedling growth through the modulation of primary and secondary metabolism

Secondary metabolites play an essential role in plant defense. However, the role of glucosinolates and phenols in brassica crop yield in the context of environmentally friendly agricultural practices has not been established. Our study investigated the effects of a Brassica extract, rich in these metabolites, on the physiology and metabolism of broccoli (Brassica oleracea L. var. italica) seedlings and the subsequent development of the plants in adult stages. The results showed an increase in growth in the extract-treated seedlings, which was associated with an alteration of primary and secondary metabolism. In particular, there was an increase in the levels of amino acids, phenolic compounds and hormones, while the levels of glucosinolates decreased. Lipid peroxidation diminished in treated plants, indicating improved membrane integrity. Treated plants subsequently grown in hydroponically showed increased water use efficiency, transpiration, and internal carbon, which contributed to the improved growth of these plants. Overall, our findings underscore the potential of the glucosinolates and phenols ratio as essential to improve crop growth and stress tolerance, as well as revealed the interest of studying the mechanisms involved in the possible uptake and integration of GSLs by broccoli seedlings after external application.

Selection of pollution-safe head cabbage: Interaction of multiple heavy metals in soil on bioaccumulation and transfer

Screening for pollution-safe cultivars (PSCs) is a cost-effective strategy for reducing health risks of crops in heavy metal (HM)-contaminated soils. In this study, 13 head cabbages were grown in multi-HMs contaminated soil, and their accumulation characteristics, interaction of HM types, and health risks assessment using Monte Carlo simulation were examined. Results showed that the edible part of head cabbage is susceptible to HM contamination, with 84.62% of varieties polluted. The average bio-concentration ability of HMs in head cabbage was Cd> > Hg > Cr > As>Pb. Among five HMs, Cd and As contributed more to potential health risks (accounting for 20.8%-48.5%). Significant positive correlations were observed between HM accumulation and co-occurring HMs in soil. Genotypic variations in HM accumulation suggested the potential for reducing health risks through crop screening. G7 is a recommended variety for head cabbage cultivation in areas with multiple HM contamination, while G3 could serve as a suitable alternative for heavily Hg-contaminated soils.

Cloning and functional verification of the male sterile gene BrQRT3 in Chinese cabbage

Chinese cabbage is a cross-pollinated crop with significant heterosis, and male sterile lines are an important way to produce hybrid seeds. In this study, a male sterile mutant msm0795 was identified in an EMS-mutagenized population of Chinese cabbage. Cytological observations revealed that the microspores failed to separate after the tetrad stage, and thus developed into abnormal pollen grains, resulting in anther abortion. MutMap combined with Kompetitive Allele Specific PCR genotyping showed that BraA01g011280.3.5 C was identified as the candidate gene, which encodes polygalacturonase QRT3 and plays a direct role in the degradation of pollen mother cell wall during microspore development, named BrQRT3. Subcellular localization and expression analyses demonstrated that BrQRT3 was localized in the cell membrane and was ubiquitously expressed in roots, stems, leaves, flower buds, and flowers, but the expression of BrQRT3 was gradually suppressed with the anther development. Ectopic expression confirmed that over-expression of BrQRT3 in qrt3 background Arabidopsis mutant can rescue the pollen defects caused by loss of AtQRT3 function. It is the first time to achieve a male sterile mutant caused by the mutation of BrQRT3 in Chinese cabbage. These findings contribute to elucidate the mechanism of BrQRT3 in regulating stamen development of Chinese cabbage.

Selenium alleviates the adverse effects of microplastics on kale by regulating photosynthesis, redox homeostasis, secondary metabolism and hormones

Kale is a functional food with anti-cancer, antioxidant, and anemia prevention properties. The harmful effects of the emerging pollutant microplastic (MP) on plants have been widely studied, but there is limited research how to mitigate MP damage on plants. Numerous studies have shown that Se is involved in regulating plant resistance to abiotic stresses. The paper investigated impact of MP and Se on kale growth, photosynthesis, reactive oxygen species (ROS) metabolism, phytochemicals, and endogenous hormones. Results revealed that MP triggered a ROS burst, which led to breakdown of antioxidant system in kale, and had significant toxic effects on photosynthetic system, biomass, and accumulation of secondary metabolites, as well as a significant decrease in IAA and a significant increase in GA. Under MP supply, Se mitigated the adverse effects of MP on kale by increasing photosynthetic pigment content, stimulating function of antioxidant system, enhancing secondary metabolite synthesis, and modulating hormonal networks.

Transcriptomics Reveals the Pathway for Increasing Brassica chinensis L. Yield under Foliar Application of Titanium Oxide Nanoparticles

In this study, Brassica chinensis L seedlings after 6 weeks of soil cultivation were treated with foliar application of TiO2 NPs (20 mg/L) for different times. Transcriptomics analysis was employed to investigate the impact of TiO2 NPs on the physiology, growth, and yield of B. chinensis L. Results showed that TiO2 NPs' exposure significantly increased the biomass, total phosphorus, and catalase enzyme activity by 23.60, 23.72, and 44.01%, respectively, compared to the untreated ones (not bulk or ion).TiO2 NPs increased the leaf chlorophyll content by 4.9% and photosynthetic rate by 16.62%, which was attributed to the upregulated expression of seven genes (PetH, PetF, PsaF, PsbA, PsbB, PsbD, and Lhcb) associated with electron transport in photosystem I and light-harvesting in leaves. The water balance of B. chinensis was improved correlating with the altered expressions of 19 aquaporin genes (e.g., PIP2;1 and NIP6;1). The expressions of 58 genes related to plant hormone signaling and growth were dysregulated, with notable downregulations in GA20, SnRK2, and PP2C and upregulations of DELLAs, SAM, and ETR. Moreover, the 11 tricarboxylic acid cycle genes and 13 glycolysis genes appear to stimulate pathways involved in promoting the growth and physiology of B. chinensis. This research contributes valuable insights into new strategies for increasing the yield of B. chinensis.

Priestia aryabhattai MBM3-Mediated Enhancement of Sulphur Metabolism in Brassica campestris

Sulphur, an essential element for plant growth, is vital for synthesizing various crucial components such as amino acids and enzymes. Its limited availability in acidic soil inhibits crop development and yield. Our research identified low pH tolerance sulphur-metabolizing bacterial isolate Priestia aryabhattai MBM3, with plant growth-promoting traits. Key sulphur-metabolizing genes viz., cysK, cysE, luxS, and a hypothetical gene, BG04-4883 were increasingly upregulated during the lag phase in acidic environments, indicating to the isolates ability to accumulate sulphur through increased activity of these essential genes. Microcosm experiment revealed bioprimed Brassica campestris L seeds with Priestia aryabhattai MBM3 had improved performance in acidic conditions, as demonstrated by agronomic and physiological, and no metabolic demand for sulphur, unlike control untreated plants which showed requirement for sulphur with significant expression of sulfate transporters, as revealed by molecular studies.

Longifolene-Derived Primary Amine Carboxylates for Sustainable Weed Management: Synthesis and Herbicidal Activity

Twelve novel longifolene-derived primary amine carboxylates were synthesized and evaluated for herbicidal activity. The structures of title compounds were confirmed by Fourier-transform infrared spectroscopy, 1H nuclear magnetic resonance (NMR), 13C NMR, and high-resolution mass spectrometry. The results showed that all the synthesized compounds exhibited higher herbicidal activity than the corresponding carboxylic acids involved in the reaction and the commercial herbicide glyphosate; some of them even possessed inhibition rates of 100% against Lolium multiflorum Lam. and Brassica campestris at low concentrations (0.039-0.313 mmol/L). Moreover, structural factors, including types of carboxylates and carbon chain length, had a great influence on the herbicidal performance. The herbicidal activity of dicarboxylates was similar to or much higher than that of corresponding monocarboxylates and glyphosate. Furthermore, compound 5l was found to be the most active candidate against the root and shoot growth of L. multiflorum Lam. and B. campestris with half maximal inhibitory concentrations (IC50) of around 0.010 and 0.023 mmol/L. The present work indicated that those prepared compounds have great potential to serve as high-performance botanical herbicides used at low doses.

Biodegradation of phenol-contaminated soil and plant growth promotion by Myroides xuanwuensis H13

Physicochemical methods for remediating phenol-contaminated soils are costly and inefficient, making biodegradation an environmentally friendly alternative approach. This study aims to screen for potential phenol-degrading bacteria and to verify the removal capacities of a selected strain in a bioaugmentation experiment at the greenhouse level using Brassica chinensis L. (Chinese cabbage) as the model plant and phenol-contaminated soil. In parallel, pot experiments were conducted using a collaborative approach based on this model system. We found that Myroides xuanwuensis strain H13 showed a high degradation capability, with a 97.67% efficiency in degrading 100 mg/L phenol. Under shaking flask conditions, H13 facilitated the solubilization of tricalcium phosphate and potassium feldspar powder. Pot experiments suggested a phenol removal percentage of 89.22% and enhanced availability of soil phosphorus and potassium for plants with H13 inoculation. In this case, the abundance of soil microbes and the activity of soil enzymes significantly increased as well. Furthermore, both photosynthesis and the antioxidant system in Chinese cabbage were enhanced following H13 inoculation, resulting in its increased yield and quality. Partial least squares path modeling revealed that H13 can primarily affect plant root growth, with a secondary impact on photosynthesis. These findings highlight the potential of biodegradation from phenol-degrading bacteria as a promising strategy for efficient phenol removal from soil while promoting plant growth and health.IMPORTANCEThis study is significant for environmental remediation and agriculture by its exploration of a more environmentally friendly and cost-effective bio-strategy in treating phenol-contaminated soil. These findings have essential implications for environmental remediation efforts and sustainable agriculture. By utilizing the biodegradation capabilities of Myroides xuanwuensis strain H13, it is possible to remove phenol contaminants from the soil efficiently, reducing their negative effects. Furthermore, the enhanced growth and health of the Chinese cabbage plants indicate the potential of this approach to promote sustainable crop production.

Bioregenerative dietary supplementation in space: Brassica rapa var. nipposinica and other Brassica cultivars

Despite the precise environmental manipulation enabled by controlled environment agriculture (CEA), plant genotype remains a key factor in producing desirable traits. Brassica rapa var. nipposinica (mizuna) is a leading candidate for supplementing deficiencies in the space diet, however, which cultivar of mizuna will respond best to the environment of the international space station (ISS) is unknown. It is also unclear if there are more inter-varietal (mizuna - mustards) or intra-varietal (mizuna - mizuna) differences in response to the ISS environment. Twenty-two cultivars of mustard greens, including 13 cultivars of mizuna, were grown under ISS-like conditions to determine which would provide the greatest yield and highest concentrations of carotenoids, anthocyanins, calcium, potassium, iron, magnesium, ascorbic acid, thiamine, and phylloquinone. The experiment was conducted thrice, and data were analyzed to determine which cultivar is most suited for further optimization of space-based cultivation. It was found that phylloquinone and β-carotene concentrations did not vary between cultivars, while all other metrics of interest showed some variation. 'Amara' mustard (B. carinata) provided the best overall nutritional profile, despite its low biomass yield of 36.8 g, producing concentrations of 27.85, 0.40, and 0.65 mg·g - 1 of ascorbic acid, thiamine, and lutein, respectively. Of the mizuna cultivars evaluated, open pollinated mibuna provided the best profile, while 'Red Hybrid' mizuna provided a complimentary profile to that of 'Amara', minimally increasing dietary iron while providing beneficial anthocyanins lacking in 'Amara'.

Granulation compared to co-application of biochar plus mineral fertilizer and its impacts on crop growth and nutrient leaching

Mechanized biochar field application remains challenging due to biochar's poor flowability and bulk density. Granulation of biochar with fertilizer provides a product ready for application with well-established machinery. However, it's unknown whether granulated biochar-based fertilizers (gBBF) are as effective as co-application of non-granulated biochar with fertilizer. Here, we compared a gBBF with a mineral compound fertilizer (control), and with a non-granulated biochar that was co-applied at a rate of 1.1 t ha-1 with the fertilizer in a white cabbage greenhouse pot trial. Half the pots received heavy rain simulation treatments to investigate nutrient leaching. Crop yields were not significantly increased by biochar without leaching compared to the control. With leaching, cabbage yield increased with gBBF and biochar-co-application by 14% (p > 0.05) and 34% (p < 0.05), respectively. Nitrogen leaching was reduced by 26-35% with both biochar amendments. Biochar significantly reduced potassium, magnesium, and sulfur leaching. Most nitrogen associated with gBBF was released during the trial and the granulated biochar regained its microporosity. Enriching fertilizers with biochar by granulation or co-application can improve crop yields and decrease nutrient leaching. While the gBBF yielded less biomass compared to biochar co-application, improved mechanized field application after granulation could facilitate the implementation of biochar application in agriculture.

Effects of particle size on toxicity, bioaccumulation, and translocation of zinc oxide nanoparticles to bok choy (Brassica chinensis L.) in garden soil

The indiscriminate use of zinc oxide nanoparticles (ZnO NPs) in daily life can lead to their release into soil environment. These ZnO NPs can be taken up by crops and translocated to their edible part, potentially causing risks to the ecosystem and human health. In this study, we conducted pot experiments to determine phytotoxicity, bioaccumulation and translocation depending on the size (10 - 30 nm, 80 - 200 nm and 300 nm diameter) and concentration (0, 100, 500 and 1000 mg Zn/kg) of ZnO NPs and Zn ion (Zn2+) in bok choy, a leafy green vegetable crop. After 14 days of exposure, our results showed that large-sized ZnO NPs (i.e., 300 nm) at the highest concentration exhibited greater phytotoxicity, including obstruction of leaf and root weight (42.5 % and 33.8 %, respectively) and reduction of chlorophyll a and b content (50.2 % and 85.2 %, respectively), as well as changes in the activities of oxidative stress responses compared to those of small-sized ZnO NPs, although their translocation ability was relatively lower than that of smaller ones. The translocation factor (TF) values decreased as the size of ZnO NPs increased, with TF values of 0.68 for 10 - 30 nm, 0.55 for 80 - 200 nm, and 0.27 for 300 nm ZnO NPs, all at the highest exposure concentration. Both the results of micro X-ray fluorescence (μ-XRF) spectrometer and bio-transmission electron microscopy (bio-TEM) showed that the Zn elements were mainly localized at the edges of leaves exposed to small-sized ZnO NPs. However, the Zn elements upon exposure to large-sized ZnO NP were primarily observed in the primary veins of leaves in the μ-XRF data, indicating a limitation in their ability to translocate from roots to leaves. This study not only advances our comprehension of the environmental impact of nanotechnology but also holds considerable implications for the future of sustainable agriculture and food safety.

Comprehensive elucidation of the differential physiological kale response to cytokinins under in vitro conditions

BACKGROUND

Kale, a versatile cruciferous crop, valued for its pro-health benefits, stress resistance, and potential applications in forage and cosmetics, holds promise for further enhancement of its bioactive compounds through in vitro cultivation methods. Micropropagation techniques use cytokinins (CKs) which are characterized by various proliferative efficiency. Despite the extensive knowledge regarding CKs, there remains a gap in understanding their role in the physiological mechanisms. That is why, here we investigated the effects of three CKs - kinetin (Kin), 6-benzylaminopurine (BAP), and 2-isopentenyladenine (2iP) - on kale physiology, antioxidant status, steroidal metabolism, and membrane integrity under in vitro cultivation.

RESULTS

Our study revealed that while BAP and 2iP stimulated shoot proliferation, they concurrently diminished pigment levels and photosynthetic efficiency. Heightened metabolic activity in response to all CKs was reflected by increased respiratory rate. Despite the differential burst of ROS, the antioxidant properties of kale were associated with the upregulation of guaiacol peroxidase and the scavenging properties of ascorbate rather than glutathione. Notably, CKs fostered the synthesis of sterols, particularly sitosterol, pivotal for cell proliferation and structure of membranes which are strongly disrupted under the action of BAP and 2iP possibly via pathway related to phospholipase D and lipoxygenase which were upregulated. Intriguingly, both CKs treatment spurred the accumulation of sitostenone, known for its ROS scavenging and therapeutic potential. The differential effects of CKs on brassicasterol levels and brassinosteroid (BRs) receptor suggest potential interactions between CKs and BRs.

CONCLUSION

Based on the presented results we conclude that the effect evoked by BAP and 2iP in vitro can improve the industrial significance of kale because this treatment makes possible to control proliferation and/or biosynthesis routes of valuable beneficial compounds. Our work offers significant insights into the nuanced effects of CKs on kale physiology and metabolism, illuminating potential avenues for their application in plant biotechnology and medicinal research.

High expression of ethylene response factor BcERF98 delays the flowering time of non-heading Chinese cabbage

MAIN CONCLUSION

BcERF98 is induced by ethylene signaling and inhibits the expression of BcFT by interacting with BcNF-YA2 and BcEIP9, thereby inhibiting plant flowering. Several stresses trigger the accumulation of ethylene, which then transmits the signal to ethylene response factors (ERFs) to participate in the regulation of plant development to adapt to the environment. This study clarifies the function of BcERF98, a homolog of AtERF98, in the regulation of plant flowering time mediated by high concentrations of ethylene. Results indicate that BcERF98 is a nuclear and the cell membrane-localized transcription factor and highly responsive to ethylene signaling. BcERF98 inhibits the expression of BcFT by interacting with BcEIP9 and BcNF-YA2, which are related to flowering time regulation, thereby participating in ethylene-mediated plant late flowering regulation. The results have enriched the theoretical knowledge of flowering regulation in non-heading Chinese cabbage (NHCC), providing the scientific basis and gene reserves for cultivating new varieties of NHCC with different flowering times.

Effects of different sizes of microplastic particles on soil respiration, enzyme activities, microbial communities, and seed germination

Microplastics (MPs) are emerging pollutants of terrestrial ecosystems. The impacts of MP particle size on terrestrial systems remain unclear. The current study aimed to investigate the effects of six particle sizes (i.e., 4500, 1500, 500, 50, 5, and 0.5 μm) of polyethylene (PE) and polyvinyl chloride (PVC) on soil respiration, enzyme activity, bacteria, fungi, protists, and seed germination. MPs significantly promoted soil respiration, and the stimulating effects of PE were the strongest for medium and small-sized (0.5-1500 μm) particles, while those of PVC were the strongest for small particle sizes (0.5-50 μm). Large-sized (4500 μm) PE and all sizes of PVC significantly improved soil urease activity, while medium-sized (1500 μm) PVC significantly improved soil invertase activity. MPs altered the soil microbial community diversity, and the effects were especially pronounced for medium and small-sized (0.5-1500 μm) particles of PE and PVC on bacteria and fungi and small-sized (0.5 μm) particles of PE on protists. The impacts of MPs on bacteria and fungi were greater than on protists. The seed germination rate of Brassica chinensis decreased gradually with the decrease in PE MPs particle size. Therefore, to reduce the impact of MPs on soil ecosystems, effective measures should be taken to avoid the transformation of MPs into smaller particles in soil environmental management.

Effect of iodine species on biofortification of iodine in cabbage plants cultivated in hydroponic cultures

Iodine is an essential trace element in the human diet because it is involved in the synthesis of thyroid hormones. Iodine deficiency affects over 2.2 billion people worldwide, making it a significant challenge to find plant-based sources of iodine that meet the recommended daily intake of this trace element. In this study, cabbage plants were cultivated in a hydroponic system containing iodine at concentrations ranging from 0.01 to 1.0 mg/L in the form of potassium iodide or potassium iodate. During the experiments, plant physiological parameters, biomass production, and concentration changes of iodine and selected microelements in different plant parts were investigated. In addition, the oxidation state of the accumulated iodine in root samples was determined. Results showed that iodine addition had no effect on photosynthetic efficiency and chlorophyll content. Iodide treatment did not considerably stimulate biomass production but iodate treatment increased it at concentrations less than 0.5 mg/L. Increasing iodine concentrations in the nutrient solutions increased iodine content in all plant parts; however, the iodide treatment was 2-7 times more efficient than the iodate treatment. It was concluded, that iodide addition was more favourable on the target element accumulation, however, it should be highlighted that application of this chemical form in nutrient solution decreased the concetrations of selected micoelement concentration comparing with the control plants. It was established that iodate was reduced to iodide during its uptake in cabbage roots, which means that independently from the oxidation number of iodine (+ 5, - 1) applied in the nutrient solutions, the reduced form of target element was transported to the aerial and edible tissues.

Co-hydrothermal carbonization of municipal sludge and agricultural waste to reduce plant growth inhibition by aqueous phase products: Molecular level analysis of organic matter

The organic matter molecular mechanism by which combined hydrothermal carbonization (co-HTC) of municipal sludge (MS) and agricultural wastes (rice husk, spent mushroom substrate, and wheat straw) reduces the inhibitory effects of aqueous phase (AP) products on pak choi (Brassica campestris L.) growth compared to HTC of MS alone is not clear. Fourier-transform ion cyclotron resonance mass spectrometry was used to characterize the differences in organic matter at the molecular level between AP from MS HTC alone (AP-MS) and AP from co-HTC of MS and agricultural waste (co-Aps). The results showed that N-bearing molecules of AP-MS and co-Aps account for 70.6 % and 54.2 %-64.1 % of all molecules, respectively. Lignins were present in the highest proportion (56.3 %-78.5 %) in all APs, followed by proteins and lipids. The dry weight of co-APs hydroponically grown pak choi was 31.6 %-47.6 % higher than that of the AP-MS. Molecules that were poorly saturated and with low aromaticity were preferentially consumed during hydroponic treatment. Molecules present before and after hydroponics were defined as resistant molecules; molecules present before hydroponics but absent after hydroponics were defined as removed molecules; and molecules absent before hydroponics but present after hydroponics were defined as produced molecules. Large lignin molecules were broken down into more unsaturated molecules, but lignins were the most commonly resistant, removed, and produced molecules. Correlation analysis revealed that N- or S-bearing molecules were phytotoxic in the AP. Tannins positively influenced the growth of pak choi. These results provide new insights into potential implementation strategies for liquid fertilizers produced from AP arising from HTC of MS and agricultural wastes.

Native desert plants have the potential for phytoremediation of phytotoxic metals in urban cities: implications for cities sustainability in arid environments

Arid regions can benefit from using native desert plants, which require minimal freshwater and can aid in remediating soil phytotoxic metals (PTMs) from traffic emissions. In this study, we assessed the ability of three native desert plants-Pennisetum divisum, Tetraena qatarensis, and Brassica tournefortii-to accumulate phytotoxic metals (PTMs) in their different plant organs, including leaves, stems, and roots/rhizomes. The PTMs were analyzed in soil and plant samples collected from Dubai, United Arab Emirates (UAE). The results indicated significantly higher levels of PTMs on the soil surface than the subsurface layer. Brassica exhibited the highest concentrations of Fe and Zn, measuring 566.7 and 262.8 mg kg-1, respectively, while Tetraena accumulated the highest concentration of Sr (1676.9 mg kg-1) in their stems. In contrast, Pennisetum recorded the lowest concentration of Sr (21.0 mg kg-1), while Tetraena exhibited the lowest concentrations of Fe and Zn (22.5 and 30.1 mg kg-1) in their leaves. The roots of Pennisetum, Brassica, and Tetraena demonstrated the potential to accumulate Zn from the soil, with concentration factors (CF) of 1.75, 1.09, and 1.09, respectively. Moreover, Brassica exhibited the highest CF for Sr, measuring 2.34. Pennisetum, however, could not translocate PTMs from its rhizomes to other plant organs, as indicated by a translocation factor (TF) of 1. In contrast, Brassica effectively translocated the studied PTMs from its roots to the stem and leaves (except for Sr in the leaves). Furthermore, Pennisetum exclusively absorbed Zn from the soil into its leaves and stems, with an enrichment factor (EF) greater than 1. Brassica showed the ability to uptake the studied PTMs in its stem and leaves (except for Fe), while Tetraena primarily absorbed Sr and Zn into its stems. Based on the CF and TF results, Pennisetum appears to be a suitable species for phytostabilization of both Fe and Zn, while Brassica is well-suited for Sr and Zn polluted soils. Tetraena shows potential for Zn phytoremediation. These findings suggest that these plants are suitable for PTMs phytoextraction. Furthermore, based on the EF results, these plants can efficiently sequester PTMs.

[Effects of Rosa roxburghii Pomace Biochar on Yield and Quality of Chinese Cabbage and Soil Properties]

In order to explore the effect of Rosa roxburghii pomace biochar on the yield and quality of Chinese cabbage and soil properties and realize the resource utilization of R. roxburghii pomace, a pot experiment was conducted to study the effect of R. roxburghii pomace biochar on the yield and quality of Chinese cabbage and soil properties by setting five biochar application rates of 0 % (CK), 1 % (T1), 3 % (T2), 5 % (T3), and 7 % (T4). The results showed that:① The application of R. roxburghii pomace biochar could significantly improve the yield and quality of Chinese cabbage, and the effect was the best at a 5 % biochar application rate. The yield, soluble solids, soluble sugar, vitamin C, total nitrogen, total phosphorus, and total potassium content of Chinese cabbage increased by 71.51 %, 40.14 %, 33.65 %, 38.08 %, 9.03 %, 28.85 %, and 35.38 %, respectively, compared with those in CK. ② The application of biochar from R. roxburghii pomace could significantly improve soil properties and increase soil nutrient content and availability. The effect was better at a 5 % biochar application rate. The soil pH, organic matter, total nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, and available potassium content increased by 41.06 %, 134.84 %, 157.48 %, 140.79 %, 341.75 %, and 627.13 %, respectively, compared with those in CK. The contents of available Fe, Mn, Cu, and Zn and exchangeable Ca and Mg increased by 37.68 %, 61.69 %, 400.00 %, 4 648.84 %, 617.17 %, and 351.42 %, respectively, compared with those in CK. ③ The application of biochar from R. roxburghii pomace could significantly enhance soil enzyme activity. Compared with those in the CK treatment, soil urease, acid phosphatase, catalase, and sucrase increased by 51.43 %-362.86 %, 90.63 %-134.14 %, 21.40 %-85.12 %, and 82.92 %-218.43 %, respectively. ④ Redundancy analysis showed that soil AK; exchangeable Ca, SOM, and AP; and available Zn were the main factors affecting the yield and quality of Chinese cabbage, and there was a significant positive correlation between them. In summary, the application of R. roxburghii pomace biochar can significantly increase the yield and quality of Chinese cabbage and improve soil properties. The preparation of R. roxburghii pomace into biochar can provide a theoretical reference for the rational utilization of R. roxburghii pomace resources.

Greenhouse gas emissions and their driving factors among different flowering Chinese cabbage (Brassica campestris L.) varieties

Crop cultivars have an influence on greenhouse gas (GHG) emissions, and there is variation between varieties. However, there are few reports available on the differences in GHG emissions and their driving factors among vegetable varieties. In this study, we conducted a field experiment to examine the variances in GHG emissions and their contributing factors among eight flowering Chinese cabbage varieties (considering growth period, leaf shape, and colour). The results showed significant differences in GHG emissions within varieties; early-maturing varieties exhibited GHG by 25.6% and 15.3%, respectively, when compared to mid- and late-maturing varieties. Among the different leaf types and color classifications, light-colored and sharp-leafed varieties had the lower global warming potential (GWP) overall. Cumulative CO2 emissions were influenced by leaf SPAD values and biomass, while cumulative N2O emissions were driven mainly by stem thickness, carbon accumulation, leaf SPAD values, and biomass. In summary, the selection of light-colored varieties with pointed leaves and shorter growth periods in actual production contributed positively to the reduction of carbon emissions from flowering Chinese cabbage production. Through efficient variety screening, this study provides a win-win strategy for achieving efficient vegetable production while also addressing the global climate challenge.

Physicochemical properties and fractal characterizations of the functionalized porous clinoptilolites for controlling alginate delivery in growing cauliflower and leaf mustard

Using natural clinoptilolite (NCP) as a carrier and alginate (Alg)-calcium as an active species, the porous silicon calcium alginate nanocomposite (Alg-Ca-NCP) was successfully fabricated via adsorption-covalence-hydrogen bond. Its structural features and physicochemical properties were detailed investigated by various characterizations. The results indicated that Alg-Ca-NCP presented the disordered lamellar structures with approximately uniform particles in size of 300-500 nm. Specially, their surface fractal evolutions between the irregular roughness and dense structures were demonstrated via the SAXS patterns. The results elucidated that the abundant micropores of NCP were beneficial for unrestricted diffusing of Alg-Ca, which was conducive to facilitate a higher loading and sustainable releasing. The Ca content of leaf mustard treated with Alg-Ca-NCP-0.5 was 484.5 mg/100g on the 21st day, higher than that by water (CK) and CaCl2 solution treatments, respectively. Meanwhile, the prepared Alg-Ca-NCPs presented the obvious anti-aging effects on peroxidase drought stress of mustard leaves. These demonstrations provided a simple and effective method to synthesize Alg-Ca-NCPs as delivery nanocomposites, which is useful to improve the weak absorption and low utilization of calcium alginate by plants.

Evaluation of two deep learning-based approaches for detecting weeds growing in cabbage

BACKGROUND

Machine vision-based precision weed management is a promising solution to substantially reduce herbicide input and weed control cost. The objective of this research was to compare two different deep learning-based approaches for detecting weeds in cabbage: (1) detecting weeds directly, and (2) detecting crops by generating the bounding boxes covering the crops and any green pixels outside the bounding boxes were deemed as weeds.

RESULTS

The precision, recall, F1-score, mAP0.5, mAP0.5:0.95 of You Only Look Once (YOLO) v5 for detecting cabbage were 0.986, 0.979, 0.982, 0.995, and 0.851, respectively, while these metrics were 0.973, 0.985, 0.979, 0.993, and 0.906 for YOLOv8, respectively. However, none of these metrics exceeded 0.891 when detecting weeds. The reduced performances for directly detecting weeds could be attributed to the diverse weed species at varying densities and growth stages with different plant morphologies. A segmentation procedure demonstrated its effectiveness for extracting weeds outside the bounding boxes covering the crops, and thereby realizing effective indirect weed detection.

CONCLUSION

The indirect weed detection approach demands less manpower as the need for constructing a large training dataset containing a variety of weed species is unnecessary. However, in a certain case, weeds are likely to remain undetected due to their growth in close proximity with crops and being situated within the predicted bounding boxes that encompass the crops. The models generated in this research can be used in conjunction with the machine vision subsystem of a smart sprayer or mechanical weeder. © 2024 Society of Chemical Industry.

Carane-3,4-diol Derivatives as Potential Water-Based Herbicides

Twelve novel carane-3,4-diol derivatives were designed, synthesized, and evaluated for their herbicidal activities against Lolium multiflorum Lam. and Brassica campestris for the first time. The relationships between the chemical structural factors, including types, the number or the carbon chain length of functional groups, associated with the lipophilicity and the herbicidal activity of the tested compounds were also discussed. The results showed that most of newly synthesized compounds had a dose-dependent, herbicidal activity against the root and shoot growths of Lolium multiflorum Lam. and Brassica campestris. Compared to carane-3,4-diol, most of the target derivatives possessed improved lipophilicity and certain solubilities in representative solvents with different polarities. Particularly, ester derivatives 3a-3b and 3e can be dissolved or dispersed in water, but also displayed higher herbicidal activity against Lolium multiflorum Lam. and Brassica campestris than other ester derivatives. The 50 % inhibitory concentration (IC50) value of compound 3e against shoot growth of Brassica campestris (0.485 mmol/L) was superior to that of commercial herbicide glyphosate (1.14 mmol/L), indicating that the potential application as a water-based herbicide for Brassica campestris control.

Identification of YUC genes associated with leaf wrinkling trait in Tacai variety of Chinese cabbage

Chinese cabbage (Brassica campestris L. ssp. chinensis (L.) Makino) stands as a widely cultivated leafy vegetable in China, with its leaf morphology significantly influencing both quality and yield. Despite its agricultural importance, the precise mechanisms governing leaf wrinkling development remain elusive. This investigation focuses on 'Wutacai', a representative cultivar of the Tacai variety (Brassica campestris L. ssp. chinensis var. rosularis Tsen et Lee), renowned for its distinct leaf wrinkling characteristics. Within the genome of 'Wutacai', we identified a total of 18 YUCs, designated as BraWTC_YUCs, revealing their conservation within the Brassica genus, and their close homology to YUCs in Arabidopsis. Expression profiling unveiled that BraWTC_YUCs in Chinese Cabbage exhibited organ-specific and leaf position-dependent variation. Additionally, transcriptome sequencing data from the flat leaf cultivar 'Suzhouqing' and the wrinkled leaf cultivar 'Wutacai' revealed differentially expressed genes (DEGs) related to auxin during the early phases of leaf development, particularly the YUC gene. In summary, this study successfully identified the YUC gene family in 'Wutacai' and elucidated its potential function in leaf wrinkling trait, to provide valuable insights into the prospective molecular mechanisms that regulate leaf wrinkling in Chinese cabbage.

The RNA-Binding Protein BoRHON1 Positively Regulates the Accumulation of Aliphatic Glucosinolates in Cabbage

Aliphatic glucosinolates are an abundant group of plant secondary metabolites in Brassica vegetables, with some of their degradation products demonstrating significant anti-cancer effects. The transcription factors MYB28 and MYB29 play key roles in the transcriptional regulation of aliphatic glucosinolates biosynthesis, but little is known about whether BoMYB28 and BoMYB29 are also modulated by upstream regulators or how, nor their gene regulatory networks. In this study, we first explored the hierarchical transcriptional regulatory networks of MYB28 and MYB29 in a model plant, then systemically screened the regulators of the three BoMYB28 homologs in cabbage using a yeast one-hybrid. Furthermore, we selected a novel RNA binding protein, BoRHON1, to functionally validate its roles in modulating aliphatic glucosinolates biosynthesis. Importantly, BoRHON1 induced the accumulation of all detectable aliphatic and indolic glucosinolates, and the net photosynthetic rates of BoRHON1 overexpression lines were significantly increased. Interestingly, the growth and biomass of these overexpression lines of BoRHON1 remained the same as those of the control plants. BoRHON1 was shown to be a novel, potent, positive regulator of glucosinolates biosynthesis, as well as a novel regulator of normal plant growth and development, while significantly increasing plants' defense costs.

Widely-targeted metabolomics and transcriptomics identify metabolites associated with flowering regulation of Choy Sum

Choy Sum, a stalk vegetable highly valued in East and Southeast Asia, is characterized by its rich flavor and nutritional profile. Metabolite accumulation is a key factor in Choy Sum stalk development; however, no research has focused on metabolic changes during the development of Choy Sum, especially in shoot tip metabolites, and their effects on growth and flowering. Therefore, in the present study, we used a widely targeted metabolomic approach to analyze metabolites in Choy Sum stalks at the seedling (S1), bolting (S3), and flowering (S5) stages. In total, we identified 493 metabolites in 31 chemical categories across all three developmental stages. We found that the levels of most carbohydrates and amino acids increased during stalk development and peaked at S5. Moreover, the accumulation of amino acids and their metabolites was closely related to G6P, whereas the expression of flowering genes was closely related to the content of T6P, which may promote flowering by upregulating the expressions of BcSOC1, BcAP1, and BcSPL5. The results of this study contribute to our understanding of the relationship between the accumulation of stem tip substances during development and flowering and of the regulatory mechanisms of stalk development in Choy Sum and other related species.