Sugars are involved in plant growth, fruit quality, and signaling perception. Therefore, understanding the mechanisms involved in soluble sugar accumulation is essential to understand fruit ...development. Here, we report that MdPFPβ, a pyrophosphate‐dependent phosphofructokinase gene, regulates soluble sugar accumulation by enhancing the photosynthetic performance and sugar‐metabolizing enzyme activities in apple (Malus domestica Borkh.). Biochemical analysis revealed that a basic helix‐loop‐helix (bHLH) transcription factor, MdbHLH3, binds to the MdPFPβ promoter and activates its expression, thus promoting soluble sugar accumulation in apple fruit. In addition, MdPFPβ overexpression in tomato influenced photosynthesis and carbon metabolism in the plant. Furthermore, we determined that MdbHLH3 increases photosynthetic rates and soluble sugar accumulation in apple by activating MdPFPβ expression. Our results thus shed light on the mechanism of soluble sugar accumulation in apple leaves and fruit: MdbHLH3 regulates soluble sugar accumulation by activating MdPFPβ gene expression and coordinating carbohydrate allocation.
In apple leaves and fruits, the basic helix‐loop‐helix transcription factor MdbHLH3 regulates sugar accumulation by activating expression of the pyrophosphate‐dependent phosphofructokinase gene MdPFPβ and coordinating carbohydrate allocation.
Summary
RAD23 (RADIATION SENSITIVE23) proteins are a group of UBL‐UBA (ubiquitin‐like‐ubiquitin‐associated) proteins that shuttle ubiquitylated proteins to the 26S proteasome for breakdown. Drought ...stress is a major environmental constraint that limits plant growth and production, but whether RAD23 proteins are involved in this process is unclear. Here, we demonstrated that a shuttle protein, MdRAD23D1, mediated drought response in apple plants (Malus domestica). MdRAD23D1 levels increased under drought stress, and its suppression resulted in decreased stress tolerance in apple plants. Through in vitro and in vivo assays, we demonstrated that MdRAD23D1 interacted with a proline‐rich protein MdPRP6, resulting in the degradation of MdPRP6 by the 26S proteasome. And MdRAD23D1 accelerated the degradation of MdPRP6 under drought stress. Suppression of MdPRP6 resulted in enhanced drought tolerance in apple plants, mainly because the free proline accumulation is changed. And the free proline is also involved in MdRAD23D1‐mediated drought response. Taken together, these findings demonstrated that MdRAD23D1 and MdPRP6 oppositely regulated drought response. MdRAD23D1 levels increased under drought, accelerating the degradation of MdPRP6. MdPRP6 negatively regulated drought response, probably by regulating proline accumulation. Thus, “MdRAD23D1‐MdPRP6” conferred drought stress tolerance in apple plants.
Based on covalent organic framework (COF) 1,3,5-tris-(4-formylphenyl)benzene-benzidine (TFPB-BD) in situ grown on Fe.sub.3O.sub.4 hollow microspheres and combined with gas chromatography-flame ...thermionic detector, a rapid and simple stir bar sorptive-dispersive microextraction method was developed for the determination of five triazole pesticides (paclobutrazol, hexaconazole, flusilazole, propiconazole, and tebuconazole). The synthesized TFPB-BD/Fe.sub.3O.sub.4 microspheres were characterized by transmission electron microscope, vibrating sample magnetometer, and thermogravimetric analysis, which showed that the material has strong magnetism and higher load capacity of COF. Under optimal conditions, the extraction equilibrium could be achieved within 9 min with detection limits of 0.17-1.48 mug L.sup.-1 (S/N = 3) and a linear range of 5-1000 mug L.sup.-1. The developed method was applied to the determination of trace triazole pesticides in apples, pears, and cabbages with recoveries from 81 to 117%. Graphical abstract
Dietary fibre modulates gastrointestinal (GI) health and function, providing laxation, shifting microbiota, and altering bile acid (BA) metabolism. Fruit juice production removes the polyphenol- and ...fibre-rich pomace fraction. The effects of orange and apple pomaces on GI outcomes were investigated in healthy, free-living adults. Healthy adults were enrolled in two double-blinded, crossover trials, being randomised by baseline bowel movement (BM) frequency. In the first trial, subjects (
91) received orange juice (OJ, 0 g fibre/d) or OJ + orange pomace (OJ + P, 10 g fibre/d) for 4 weeks, separated by a 3-week washout. Similarly, in the second trial, subjects (
90) received apple juice (AJ, 0 g fibre/d) or AJ + apple pomace (AJ + P, 10 g fibre/d). Bowel habit diaries, GI tolerance surveys and 3-d diet records were collected throughout. Fresh faecal samples were collected from a participant subset for microbiota and BA analyses in each study. Neither pomace interventions influenced BM frequency. At Week 4, OJ + P tended to increase (
= 0·066) GI symptom occurrence compared with OJ, while AJ + P tended (
= 0·089) to increase flatulence compared with AJ. Faecalibacterium (
= 0·038) and Negativibacillus (
= 0·043) were differentially abundant between pre- and post-interventions in the apple trial but were no longer significant after false discovery rate (FDR) correction. Baseline fibre intake was independently associated with several microbial genera in both trials. Orange or apple pomace supplementation was insufficient to elicit changes in bowel habits, microbiota diversity or BA of free-living adults with healthy baseline BM. Future studies should consider baseline BM frequency and habitual fibre intake.
Research into autonomous (robotic) apple picking has not yet resolved the problem of finding the optimal picking orientation. Robotic picking efficiency, in terms of picking all available apples ...without loss or damage, remains low. This paper proposes a method of determining the optimal picking orientation relative to the target fruit and adjacent branches from the point cloud of the apple and the surrounding space. The picking mechanism is then able to avoid branches and accurately grasp the target apple in order to pick it. The apple is first identified by the YOLOv3 target detection algorithm, and a point cloud of the fruit and the space surrounding it is obtained. The random sample consensus algorithm RANSAC is used for sphere fitting, and the fruit is idealized as a sphere. RANSAC also idealizes the branch as a line that is fitted to the branch bearing the target apple in the point cloud around it. The distance between the line of the branch and the fruit centroid is constrained in fitting to ensure identification of the branch/line closest to the apple/sphere. The best apple picking orientation is determined from the positional relationship between the straight branch/line and the center of the apple/sphere. The performance of the algorithm was evaluated using apples with various orientations on growing trees. The average angle error between the calculated picking direction vector and the expected direction vector was 11.81°, and the standard deviation was 13.65°; 62.658% of the determinations erred by ≤10°, and 85.021% erred by ≤20°. The average time for estimating the orientation of an apple was 0.543 s. The accuracy and speed of the algorithm enabled the robotic picker to operate at a speed that matches that of a human apple picker.
Performance of the BL03U beamline at SSRF Sun, Z. P.; Liu, Z. H.; Liu, Z. T. ...
Journal of synchrotron radiation,
September 2020, Letnik:
27, Številka:
5
Journal Article
Recenzirano
The vacuum ultraviolet beamline BL03U with a photon energy range from 7 eV upwards has been constructed at the 3.5 GeV Shanghai Synchrotron Radiation Facility. Equipped with an APPLE‐Knot undulator, ...this beamline is dedicated to angle‐resolved photoemission spectroscopy. An energy‐resolving power of higher than 4.6 × 104 has been achieved in the photon energy range 21.6–48 eV, which is almost the same as the theoretical estimation.
The design and performance test of the vacuum ultraviolet beamline BL03U at SSRF are described.
In plants, flavonoids are important secondary metabolites that contribute to the nutritional quality of many foods. Apple is a popular and frequently consumed food because of its high flavonoid ...content. In this study, flavonoid composition and content were detected and compared between red- and white-fleshed apples in a BC1 hybrid population using ultraperformance liquid chromatography–quadrupole time-of-flight mass spectrometry. Transcriptomic analysis of the red- and white-fleshed apples was then performed using RNA-seq technology. By screening differentially expressed genes encoding transcription factors, we unearthed a WRKY-family transcription factor designated MdWRKY11. Overexpression of MdWRKY11 promoted the expression of F3H, FLS, DFR, ANS, and UFGT and increased the accumulation of flavonoids and anthocyanin in apple calli. Our findings explored the novel role of MdWRKY11 in flavonoid biosynthesis and suggest several other genes that may also be potentially involved. This provides valuable information on flavonoid synthesis for the breeding of elite red-fleshed apples.
Introducing areas of wildflower vegetation within crop fields has been shown to enhance pollinator activity and pollination services to crops, and findings in Europe showed an interaction effect ...between floral treatments and landscape context. Natural fynbos patches in the South African Cape Floristic Region (CFR) are potential reservoirs for beneficial insects that could enhance pollinator populations and crop pollination in commercial apple orchards. However, the effect of proximity to natural habitat and floral enhancement treatments on crop pollinators and yield are yet to be fully tested in southern temperate regions.
To elucidate the impact of enhanced floral resources to apple flower visitors and crop yield, we established small experimental patches of flowers in non‐productive areas of commercial apple Malus domestica orchards in the CFR. Experimental orchards were embedded in landscapes with varying proportions of natural habitat within 1 km. We used pollinator exclusion experiments to determine the benefits of insect pollination on apple yield, quality and economic value.
We found that the primary pollinator of apple flowers in the region is the endemic Cape honey bee, Apis mellifera capensis. Floral plantings enhanced overall pollinator abundance and honey bee flower visitation within the orchards, and positively affected apple size and economic value. Increased landscape complexity had a significantly positive effect on wild bees but not on honey bees.
Synthesis and applications. We demonstrate that presence of floral plantings within orchards enhances pollinator activity within apple orchards and apple quality. This sustainable management practice may represent a profitable choice for growers, which could increase pollination services while reducing reliance on renting hives. These practices can indirectly contribute to increased landscape‐scale resilience and connectivity while also benefiting pollinators within the remaining natural habitat.
We demonstrate that presence of floral plantings within orchards enhances pollinator activity within apple orchards and apple quality. This sustainable management practice may represent a profitable choice for growers, which could increase pollination services while reducing reliance on renting hives. These practices can indirectly contribute to increased landscape‐scale resilience and connectivity while also benefiting pollinators within the remaining natural habitat.
Nutrient stress harms plant growth and yield. Melatonin is a biologically active, multifunctional hormone that relieves abiotic stress in plants. Although previous studies have shown that melatonin ...plays an important role in improving nutrient-use efficiency, the mechanism of its regulation of nutrient stress remains unclear. In this study, melatonin was applied to apple plants under nutrient stress, and morphological indices, physiological and biochemical indices, and stomatal morphology were evaluated. The response of apple plants to nutrient deficiency and the melatonin mechanism to alleviate nutrient stress were analyzed by combining ionome, transcriptome, and metabolome. The results showed that exogenous melatonin significantly alleviated the inhibitory effect of nutritional stress on the growth of apple plants by regulating stomatal morphology, improving antioxidant enzyme activity, promoting ion absorption, and utilizing and changing the absorption and distribution of minerals throughout the plant. The transcriptome results showed that melatonin alleviated nutrient stress and promoted nutrient absorption and utilization by regulating glutathione metabolism and upregulating some metal ion transport genes. The metabolome results indicated that levels of oxalic acid, L-ascorbic acid, anthocyanins (cyanidin-3-O-galactoside), lignans (lirioresinol A and syringaresinol), and melatonin significantly increased after exogenous melatonin was applied to plants under nutrient stress. These differentially expressed genes and the increase in beneficial metabolites may explain how melatonin alleviates nutrient stress in plants.
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