Soluble Sugar Content Research Articles

Influence of Elevated Potassium Fertilization on Structural and Functional Properties of Sweet Potato Root Tuber Starch

Nine sweet potato varieties with different flesh colors were cultivated under uniform environmental conditions with potassium (K) fertilizer treatments at levels of 0, 22.5, and 45 kg/ha. The structural and functional properties of the starches were subsequently analyzed. The soluble sugar content in the dry root tuber increased, with higher K levels in most varieties. Amylose content decreased in Sushu16 but increased in Ningzishu1, with no significant differences observed in other varieties across different K levels. Elevated K levels had no effect on starch protein content, crystalline type, or gelatinization enthalpy. The impact of K fertilizer on starch thermal and pasting properties varied among the varieties. PLSR and PLS-DA analyses revealed that genotype background was the primary factor influencing starch properties. This research will provide a reference for the improvement of sweet potato production quality and efficiency and a scientific basis for the cultivation and utilization of sweet potato root tubers.

Higher endogenous abscisic acid confers greater tolerance to saline-alkaline stress in Petunia hybrida

Saline-alkaline stress not only leads to reduced crop yields but also diminishes the ornamental value of flowers. While petunia exhibits tolerance to saline-alkaline stress, research on the mechanisms underlying this tolerance remains unreported. We investigated the physiological and molecular mechanisms underlying saline-alkaline stress tolerance using two petunia genotypes (Haishishenlou and Mitchell Diploid) with differing tolerance levels. Haishishenlou exhibited less inhibition of growth under saline-alkaline stress compared to Mitchell Diploid, as indicated by higher biomass. Higher endogenous concentration of abscisic acid (ABA) and greater expression levels of ABA biosynthetic genes and lower expression levels of ABA catabolic genes in Haishishenlou than in Mitchell Diploid were observed when challenged by saline-alkaline stress, suggesting that a higher concentration of ABA may underpin the greater tolerance of Haishishenlou to saline-alkaline stress than that of Mitchell Diploid. Under saline-alkaline conditions, Haishishenlou displayed higher chlorophyll content, photosynthetic rates, Pro and soluble sugars content, as well as higher activities of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD), and a lower Na+/K+ ratio. Exogenous application of ABA alleviated the growth inhibition induced by saline-alkaline stress, promoted the accumulation of proline and soluble sugar, reduced reactive oxygen species (ROS) content and Na+/K+ ratio, and improved antioxidative capacity. These results indicated that a higher endogenous concentration of ABA may underpin the greater tolerance of petunia seedlings to saline-alkaline stress, and exogenous ABA improves the saline-alkaline tolerance of petunia seedlings.

Foliar Spraying of Potassium Sulfate during Fruit Development Comprehensively Improves the Quality of Citrus Fruits

Sugar accumulation is influenced by various fertilizer treatments, of which potassium spraying is the most effective. However, the effect of different potassium sources as a foliar application at different fruit development stages on citrus fruits is still unclear. In this study, three different potassium fertilizers and one water (F1: 0.65% KNO3, F2: 0.88% KH2PO4, F3: 0.56% K2SO4, and F4: water) were sprayed on Citrus reticulata cv. Nanfeng at cell division, cell expansion, fruit ripening, and throughout fruit developmental stages, respectively. Results showed that the six-time K2SO4 application had the best function in enhancing fruit physiological attributes such as fruit weight and the total carotenoids; also, this treatment significantly decreased TA (titratable acid), increased fruit TSS (total soluble solids), soluble sugar content, and TSS:TA ratio. Furthermore, K2SO4 spraying obviously increased the expression of CsCWINV-2/6 in the segment membrane, and CsSUT-1/2 and CsVPP-1/2 in fruit juices. Taken together, six-time application of K2SO4 throughout fruit developmental stages produced better fruit quality, at least through enhancing sink strength and promoting sugar transportation in citrus fruits. This study might effectively contribute to maximizing fruit quality and its marketability.

Effect of Different Light Intensities on the Quality of ‘Korla’ Fragrant Pear Fruits

This study aimed to investigate the effect of different light intensities on the quality of ‘Korla’ fragrant pear fruits. The differences in fruit quality were determined by evaluating the pigment content and fluorescent characteristics of the peel. The date of fruit weight, aspect ratio, soluble sugar content, soluble solid content, reducing sugar content, and vitamin C content of fruits, were higher under 100% light intensity than in shade treatment. However, firmness of the peel and pulp, and titratable acid content were enhanced in shade-treatment. Total chlorophyll, Chl a, and Chl b contents gradually decreased with the reduction in light intensity. The anthocyanin content gradually decreased with the decrease in light intensity. The maximum photochemical efficiency (FV/FM) of PSII significantly declined at 1% light intensity. As the light intensity decreased, the actual fluorescence quantum efficiency of PSII (F′V/F′M), non-photochemical quenching (NPQ), and actual photochemical efficiency of PSII (ΦPS II) progressively decreased. The results indicate that photoinhibition occurred in the peel of fragrant pear fruits. Shade treatment reduced the intrinsic quality of ‘Korla’ fragrant pear fruits, whereas a moderate decrease in light intensity could enhance the extrinsic quality of fruits.

Highland barley ELNs and physiological responses to different concentrations of Cr (VI) stress.

This study is the first to use highland barley (HB) to study the toxic effects of Cr (VI) on seedlings and the response mechanism of HELNs to Cr (VI) stress. The outcomes indicated that the germination rate of HB seeds, plant height, root length, water content, and levels of proline (PRO) and soluble sugar in both leaves and roots were all impacted by varying concentrations of Cr (VI) treatments. Differential changes in the activities of antioxidant enzymes (SOD, POD, CAT) were observed in leaves and roots of HB. We also extracted HB-derived ELNs (HELNs) and characterized and sequenced HELNs. The average particle size of CK-HELNs was 79.0 nm, and the concentration of HELNs was 4.56 E+10 (particles/mL). As the concentration of Cr (VI) increased, the particle size of HELNs in HB seedlings also increased, while the concentration decreased. A total of 29 miRNA species were identified in CK-HELNs, Cr10-HELNs, and Cr40-HELNs. Out of these, 25 were newly predicted miRNAs, and the remaining four were known miRNAs. A total of 2 known miRNAs and 11 novel miRNAs were upregulated under different concentrations of Cr (VI) stress. 1 known and 5 novel miRNAs were downregulated under different concentrations of Cr (VI) stress. Enrichment of the GO and KEGG pathways revealed that the differential gene functions were mainly focused on binding and catalytic activities. This study reveals for the first time the changes of HELNs under different concentrations of Cr (VI) stress and the toxic effects of Cr (VI) on HB seedlings. This study provides a new perspective to explore the function and utilisation of ELNs.

CBL1/CIPK23 phosphorylates tonoplast sugar transporter TST2 to enhance sugar accumulation in sweet orange (Citrus sinensis).

Fruit taste quality is greatly influenced by the content of soluble sugars, which are predominantly stored in the vacuolar lumen. However, the accumulation and regulation mechanisms of sugars in most fruits remain unclear. Recently, we established the citrus fruit vacuole proteome and discovered the major transporters localized in the vacuole membrane. Here, we demonstrated that the expression of tonoplast sugar transporter 2 (CsTST2) is closely associated with sugar accumulation during sweet orange (Citrus sinensis) ripening. It was further demonstrated that CsTST2 had the function of transporting hexose and sucrose into the vacuole. Overexpression of CsTST2 resulted in an elevation of sugar content in citrus juice sac, calli, and tomato fruit, whereas the downregulation of its expression led to the reduction in sugar levels. CsTST2 was identified as interacting with CsCIPK23, which binds to the upstream calcium signal sensor protein CsCBL1. The phosphorylation of the three serine residues (Ser277, Ser337, and Ser354) in the loop region of CsTST2 by CsCIPK23 is crucial for maintaining the sugar transport activity of CsTST2. Additionally, the expression of CsCIPK23 is positively correlated with sugar content. Genetic evidence further confirmed that calcium and CsCIPK23-mediated increase in sugar accumulation depends on CsTST2 and its phosphorylation level. These findings not only unveil the functional mechanism of CsTST2 in sugar accumulation, but also explore a vital calcium signal regulation module of CsCBL1/CIPK23 for citrus sweetness quality.

Exogenous GABA improves tomato fruit quality by contributing to regulation of the metabolism of amino acids, organic acids and sugars

To better explore the impact of exogenous GABA on tomato fruit quality, we explored the effects of GABA (20 mM) on tomato fruits at different developmental stages. The results showed that spraying GABA 3 days before harvest improved the quality of fruits, primarily in terms of amino acid, organic acid, and soluble sugar content. Transcriptome and metabolome data indicated that exogenous GABA enters cells and mitochondria through GABA transporters, thereby simulating endogenous GABA metabolism and enhancing the activity of genes related to amino acids and organic acids metabolism, and elevating the levels of amino acids and organic acids. Moreover, the application of exogenous GABA promoted the contents of glucose, fructose, and sucrose by affecting the expression of genes related to sugar metabolism. It was found that the mechanism of exogenous GABA in increasing fruit sugar content involved promoting sucrose synthesis, partially inhibiting glycolysis, and increasing the content of trehalose 6-phosphate. This study also provides a new model for the mechanism through which exogenous GABA affects tomato quality.

Arbuscular mycorrhizal fungi alleviate Mn phytotoxicity by altering Mn subcellular distribution and chemical forms in Lespedeza davidii

IntroductionArbuscular mycorrhizal fungi (AMF) can relieve manganese (Mn) phytotoxicity and promote plant growth under Mn stress, but their roles remain unclear.MethodsIn this study, Lespedeza davidii inoculated with or without AMF (Glomus mosseae) under different Mn concentrations (0 mmol/L, 1 mmol/L, 5 mmol/L, 10 mmol/L, and 20 mmol/L) was cultivated via a pot experiment, and plant biomass, physiological and biochemical characteristics, manganese absorption, subcellular distribution, and chemical forms of Mn were examined.ResultsThe results showed that root biomass, stem biomass, leaf biomass, and total individual biomass decreased under high Mn concentrations (above 10 mmol/L), and the inoculated plants had higher biomass than the uninoculated plants. With the increasing Mn concentration, the contents of soluble sugar, soluble protein, free proline, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased first and then decreased, while the malondialdehyde (MDA) content increased. The contents of soluble sugar, soluble protein, free proline, SOD, POD, and CAT in the inoculated group were higher than those in the uninoculated group at the Mn concentration of 20 mmol/L. The content of MDA in the inoculated plants was lower than that in the uninoculated plants. AMF inoculation enriched most of the manganese in the root system when compared with the non-mycorrhizal treatment. Subcellular distribution of Mn indicated that most of the Mn ions were stored in the cell wall and the vacuoles (the soluble fractions), and the proportion of Mn content in the cell wall components and the vacuole components in leaves in the inoculated group was higher than that in the uninoculated group. Furthermore, the proportions of Mn extracted using ethanol and deionized water in the uninoculated group in stems and roots were higher than those in the inoculated group, which suggested that AMF could convert Mn into inactive forms.DiscussionThe present study demonstrated that AMF could improve the resistance of L. davidii to Mn toxicity by increasing the activity of antioxidant enzymes and altering the subcellular distribution and chemical forms of Mn.

Silicon Enhanced Italian Ryegrass (Lolium multiflorum) Production and Induced Defense Responses Against Fall Armyworm (Spodoptera frugiperda)

The spread of invasive pests exacerbates the direct damage to host plants and the potential threat to the environment. Silicon has the potential to enhance host plant resistance to insects while also increasing plant yield. This study evaluated changes in Italian ryegrass biological yield and resistance to fall armyworm (Spodoptera frugiperda) larvae after silicon supplementation (sodium silicate and potassium silicate at 6 mmol·L−1 were denoted as groups T1 and T2, respectively). Silicon supplementation significantly increased the shoot biological yield (T1 by 30.26%, T2 by 23.05%) and silicon content (T1 by 22.61% and T2 by 12.43%) of Italian ryegrass. At the same time, silicon supplementation increased the protein, soluble sugar, and vitamin contents of Italian ryegrass, while also stimulating the improvement of its physical and chemical defenses. Therefore, even though the nutrient intake of fall armyworm increased, the synergistic physical-chemical defense formed by silica deposition, flavonoid content, and increased protease inhibitor activity in the Italian ryegrass still weakened the antioxidant capacity of the larvae and inhibited larval feeding and protein accumulation. The larval body weight of the T1 and T2 groups decreased by 20.32% and 15.16%, respectively. The comprehensive scores showed that sodium silicate and potassium silicate of the same concentration had similar effects on the growth and insect resistance of Italian ryegrass. These findings suggest that both sodium and potassium silicate are effective silicon supplements for host plants. Therefore, reasonable supplementation of silicon fertilizer may become an important alternative plan for optimizing the comprehensive pest control strategy in agricultural production areas in the future, but this still needs further field research verification.

Comparative Metabolic Defense Responses of Three Tree Species to the Supplemental Feeding Behavior of Anoplophora glabripennis

Elaeagnus angustifolia L. can attract adult Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky), and kill their offspring by gum secretion in oviposition scars. This plant has the potential to be used as a dead-end trap tree for ALB management. However, there is a limited understanding of the attraction ability and biochemical defense response of E. angustifolia to ALB. In this study, we conducted host selection experiments with ALB and then performed physiological and biochemical assays on twigs from different tree species before and after ALB feeding. We analyzed the differential metabolites using the liquid chromatograph–mass spectrometer method. The results showed that ALB’s feeding preference was E. angustifolia > P.× xiaohei var. gansuensis > P. alba var. pyramidalis. After ALB feeding, the content of soluble sugars, soluble proteins, flavonoids, and tannins decreased significantly in all species. In three comparison groups, a total of 492 differential metabolites were identified (E. angustifolia:195, P.× xiaohei var. gansuensis:255, P. alba var. pyramidalis:244). Differential metabolites were divided into overlapping and specific metabolites for analysis. The overlapping differential metabolites 7-isojasmonic acid, zerumbone, and salicin in the twigs of three tree species showed upregulation after ALB feeding. The specific metabolites silibinin, catechin, and geniposide, in E. angustifolia, significantly increased after being damaged. Differential metabolites enriched in KEGG pathways indicated that ALB feeding activated tyrosine metabolism and the biosynthesis of phenylpropanoids in three tree species, with a particularly high enrichment of differential metabolites in the flavonoid biosynthesis pathway in E. angustifolia. This study provides the metabolic defense strategies of different tree species against ALB feeding and proposes candidate metabolites that can serve as metabolic biomarkers, potentially offering valuable insights into using E. angustifolia as a control measure against ALB.

Drought induces opposite changes in organ carbon and soil organic carbon to increase resistance on moso bamboo

IntroductionThe variety of organs carbon concentration may be important for tree survival rate, drought resistance and tree subsequent recovery. However, it remains unclear how drought affect structural carbohydrate (SC) and non–structural carbohydrate (NSC) export and transport on clonal plant, which can be correlated with sustain physiological metabolism and group drought resistance by resource sharing. To better understand the adaption ability of clone plants to drought and the linkage of organ carbon with soil organic carbon (SOC) fractions, we assessed how long–term drought affects organ carbon and its impact on SOC fractions among moso bamboo (Phyllostachys edulis) ramets.MethodsThroughfall exclusion included two treatments with simulated drought (TE) and control sample (CK, natural rainfall) by waterproofing panels, which excluded 70–80% of the precipitation. We measured the SC and NSC of leaves, branches and roots as well as soil organic carbon components on three ramets, which emerged in 2017 (grandma, GB), ramets that appeared in 2018 (mother bamboo, MB) and ramets emerging in 2019 (current-year bamboo, CB).ResultsThe results showed that there was significant difference on lignin, cellulose: lignin ratio and soluble sugar in leaves and roots (p<0.05) instead of branches (p>0.05). Effect of drought on SC and NSC varied with different organs and ramet age. Drought significantly increased soluble sugar concentration of leaves and roots by 15.5–31.0% and 10.6–24.8% for current-year bamboo. Compared with CK, drought decreased SOC by 6.7–19.1%, microbial biomass carbon (MBC) by 55.3–68.7%, readily oxidizable carbon (ROC) by 11.2–29.8%, particulate organic carbon (POC) by 25.1–47.4% but no effect on mineral–associated organic carbon (MOC). Drought changed the relationships of carbon components between plant organs and soil. In the control treatments, SC of leaves were significantly positively correlated with ROC, NSC of branches were positively correlated with ROC and MBC, NSC of roots were significantly positively correlated with SOC.DiscussionOverall, our results suggest that drought strengthened the linkage of plant organ carbon and soil carbon cycling among moso bamboo ramets in ecosystem studies, which are critical for predicting tree resistance and management in subtropical forest under drought.

Impact of Different Plant Growth Regulators on Growth, Yield and Quality of Fennel (Foeniculum vulgare Mill.) in Alluvial Regions of West Bengal

An experiment was conducted during the rabi seasons (November, 2018 –April, 2020) at the Horticultural Research Station, Mondouri, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal (741 252), India to assess the impact of different plant growth regulators on the growth, yield, and quality of fennel (Foeniculum vulgare Mill.). The experiment was designed in Randomized Block Design with a total of 9 treatment combinations that were replicated three times. Fennel seeds were sown during the first week of November in 2.5×1.5 m2 plots with a spacing of 50×30 cm2. Growth regulators were applied at 30, 45, and 60 days after sowing. The results revealed that the application of naphthalene acetic acid @ 100 ppm significantly optimized fennel yield and quality in the alluvial regions of West Bengal. This was evident through various yield and its attributing parameters, including number of umbel plant-1, number of umbellate umbel-1, number of seeds umbellate-1, test weight (g), and seed yield (22.95 q ha-1) as well as quality parameters including total soluble sugar content (2.91 mg 100 mg-1) and volatile oil content (1.448%). Additionally, Kinetin @ 10 parts per million significantly enhanced the total chlorophyll content (0.344 mg g-1), while gibberellic acid positively influenced growth parameters like plant height, number of primary and secondary branches, days to 50% flowering, flower stalk length, and umbel diameter.

Chickpea Proteome Analysis Reveals Genotype-Dependent Variations Associated with Seed Traits.

Chickpea (Cicer arietinum L.) is the second most widely grown legume crop after soybean. Here, we measured the macronutrients and performed proteome profiling of eight chickpea cultivars using two complementary protein extraction solvents. The total protein, starch, and soluble sugar contents significantly differ between cultivars, and we quantified 2434 and 1809 proteins, respectively, from urea- and water-based extraction solvents using a data-independent acquisition approach. The proteome-level differences can vary from 9-25% for the urea-extracted proteins, and the storage protein abundances significantly differed between the cultivars, where legumin content was detected as the highest, followed by vicilin and albumin. Fifty common allergens were detected from two extraction solvents, primarily overrepresented in chromosomes 3, 4, and 5. Integrated analysis revealed distinct subclusters of proteins and their associated pathways for total protein, lipids, and starch content. Overall, we established chickpea pan-proteome resources and provided insights into the key pathways that define the genotypes.

Effect of Paclobutrazol on Biochemical and Yield Attributes of Chickpea (Cicer arietinum L.)

The experiment was carried out during the rabi (winter) season ( 2nd week of November to last week of Feburary) of 2019 and 2020 at the District Seed Farm, ‘AB’ block, Kalyani at Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal to study the effect of paclobutrazol on the biochemical and yield attributes of chickpeas with yield. The experiment was laid down in a randomized block design having six treatments of a formulation of paclobutrazol 40% (0, 25, 35, 45, 55 and 65 ml ha-1) with each replicated four times and the experimental material for the study consisted of chickpea variety was JAKI 92-18. Results revealed that Paclobutrazol caused to decline in the leaf chlorophyll content and enhanced the accumulation of storage carbohydrates particularly starch in the leaf. Leaf soluble sugar content was lowest in the control (2.86) and all the treatments were significantly higher than the control in this respect. It caused to enhance the seed yield by enhancing the number of seeds plants-1 and improving the harvest index. The highest yield was obtained in paclobutrazol 35 ml ha-1 (2008 kg ha-1); other treatments with substantially higher yields than control were paclobutrazol 45 ml ha-1 (1783 kg ha-1), and paclobutrazol 25 ml ha-1 (1692 kg ha-1). Hence, foliar application of Paclobutrazol @ 35 ml l-1 may be most effective in augmenting the yield attributes and yield of chickpea during rabi season.

Physiological characteristics during the formation of aromatic components in xylem of Aquilaria sinensis induced by exogenous substances.

An inductive combination of plant growth regulators, inorganic salts, and fungi is essential for the formation of aromatic components in the xylem of Aquilaria sinensis. However, the dynamics of xylem physiology and the relationships between physiological properties and aromatic components after artificial induction remain unclear. In this study, the changes in physiological properties of A. sinensis xylem during induction were determined and analyzed under four induction treatments and a control group. The defense hormone contents of jasmonic acid, salicylic acid, aminocyclopropane-1-carboxylic acid, and abscisic acid obtained from the four induction treatments increased significantly. However, the concentrations of gibberellin and indoleacetic acid were decreased compared to the control group. An initially upward and then downward trend was observed in the main antioxidant enzyme activities. Additionally, malonaldehyde content decreased obviously, while proline content tended to increase and then decrease as induction continued. The total and soluble sugar content was evidently reduced after treatment, and the soluble sugar content recovered more rapidly with time. Thirty-three aromatic components were identified in all treatments, and the primary aromatic components were terpenes, aromatics and chromones, the relative contents of which varied among treatments. These results provide new insights for optimization and innovation of agarwood induction techniques by exploring the formation of aromatics in the xylem of A. sinensis and its physiological responses following induction with exogenous substances (ethephon, NaCl, CaCl2 and fungal mixed solution).

Light Intensity Effects on Productivity and Post-Harvest Quality in Perilla frutescens Cultivated in CEA

Leafy vegetables, mainly lettuces, are currently the main crop cultivated in controlled environment agriculture (CEA), including vertical farming and plant factories. There is a rising demand to expand this portfolio with a wider variety of underutilized edible plants containing various bioactive compounds and sensory properties seeking to enrich human diets. However, the optimal cultivation conditions for these underutilized plants significantly differ from those optimized for lettuce, basil, and other popular CEA crops. Therefore, this study aims to explore the impacts of light-emitting diode (LED) lighting intensity (photosynthetic photon flux density, PPFD) on green leaf Perilla frutescens cultivated in CEA. Plants were grown under four levels of LED lighting PPFDs from 150 to 300 µmol m−2s−1 for 4 weeks. Plant biomass productivity, soluble sugar contents, antioxidant properties (DPPH, ABTS free radical scavenging activities, FRAP antioxidant power), and total contents of phenolic compounds in leaves were evaluated at harvesting time. Further, harvested plant material was stored in the dark, at +6 °C, and the water content, water loss and transpiration rate, leaf sugar contents, and antioxidant properties were monitored 1, 3, and 5 days after harvesting. The summarized data suggest that higher cultivation lighting PPFD results in better harvest quality preservation during post-harvest storage.

Exploring sugar allocation and metabolic shifts in cassava plants infected with Cassava common mosaic virus (CsCMV) under long-day photoperiod: diel changes in source and sink leaves.

Cassava common mosaic virus (CsCMV) is a potexvirus that impairs chloroplast and metabolism, causing significant yield losses to cassava crops. Crop yield depends on diel rhythms, influencing carbon allocation and growth, and sugar signaling also impacting light-dark rhythms. This study aimed to elucidate the early impact of CsCMV infection on diel carbon allocation, metabolism, and defense mechanisms in both source and sink cassava leaves before storage root bulking. Soluble sugar and starch concentrations were examined over a 24-h cycle (16:8 photoperiod) in CsCMV-infected plants. The expression of an array of genes-carbohydrate metabolism, SnRK1 activity marker, defense, circadian marker-was analyzed at ZT6, ZT16 and ZT24/ZT0. In CsCMV-infected source leaves, at ZT6, sucrose increased whereas glucose, fructose and sucrose rose at night. An increase in Suc:hexose ratio and upregulation of SnRK1 activity marker genes and PR1 transcripts were found in infected leaves, suggesting a combination of altered carbon metabolism and defense response mechanisms against the viral infection. GIGANTEA, a clock-controlled gene, showed a reduced expression in infected leaves at ZT6 and ZT24/ZT0, suggesting a circadian phase shift compared with uninfected control plants. Additionally, starch mobilization transcripts were downregulated at ZT24/ZT0, though starch content remained unchanged during the 24-h cycle. In sink leaves, a transient peak of maltose (ZT6) was observed. Our findings suggest that CsCMV disrupts the plant's natural rhythms of sugar metabolism and allocation. Spikes in sucrose levels may serve as infection signals in the internal daily clock of the plant, influencing plant responses during the cassava-CsCMV interaction.

In Vitro Evaluation of Iraqi Kurdistan Tomato Accessions Under Drought Stress Conditions Using Polyethylene Glycol-6000.

Drought is one of the major abiotic stresses that affect plant growth and productivity, and plant stress responses are affected by both the intensity of stress and genotype. In Iraqi Kurdistan, tomato plants play a significant role in the country's economy. Due to climate change, which causes soil moisture to diminish, the crop's growth and yield have been dropping in recent years. Accordingly, the effects of simulated drought stress on germination parameters were assessed in 64 tomato accessions gathered from the Iraqi Kurdistan region in order to identify sensitive and tolerant accessions. In this respect, the responses associated with drought stress were observed phenotypically and biochemically. Germination percentage (GP) and morphological characteristics such as root length (RL), shoot length (SL), and shoot fresh weight (SFW) were significantly reduced in both stress treatments with polyethylene glycol (PEG-6000) (7.5% PEG and 15% PEG). On the other hand, significant changes in biochemical profiles such as proline content (PC), soluble sugar content (SSC), total phenolic content (TPC), antioxidant activity (AC), guaiacol peroxidase (GPA), catalase (CAT), and lipid peroxidation (LP) in tomato accessions were detected; all biochemical traits were increased in most tomato accessions under the PEG-induced treatments compared to the control treatment (0.0% PEG). Three tomato accessions (AC61 (Raza Pashayi), AC9 (Wrdi Be Tow), and AC63 (Sandra)) were found to be the most tolerant accessions under all drought conditions, whereas the performances of the other tested accessions (AC13 (Braw), AC30 (Yadgar), and AC8 (Israili)) were inferior. The OMIC analysis identified the biomarker parameters for differentiating the highly, moderately, and low tolerant groups as PC, SSC, and TPC. This study shows that early PEG-6000 screening for drought stress may help in choosing a genotype that is suitable for growth in water-stressed environments. Hence, Raza Pashayi, Wrdi Be Tow, and Sandra accessions, which had great performances under drought conditions, can be candidates for selection in a breeding program to improve the growth of plants and production in the areas that face water limits.

Full-length single-molecule sequencing uncovers novel insight into the global landscape of the cold stress response in trifoliate orange (Citrus trifoliata).

Trifoliate orange (Citrus trifoliata (L.) Raf.) is a cold-hardy citrus species that contributes to citrus production by frequently serving as a rootstock. Nevertheless, the molecular mechanisms underlying cold tolerance in citrus, particularly post-transcriptional regulation, remain largely unidentified. In this study, we constructed a transcriptome map of trifoliate orange subjected to cold stress by integrating full-length single-molecule sequencing and Illumina short-read sequencing. The hybrid sequencing approach yielded a more comprehensive set of full-length transcripts than was previously available from the reference genome. In particular, the high-quality transcripts enabled the detection of extensive alternative splicing (AS), with intron retention (IR) identified as the predominant AS event in trifoliate orange. Transcriptome analysis revealed that genes associated with starch and sucrose metabolism were significantly enriched among the cold-responsive genes. Consistent with these data, soluble sugar content was elevated by the cold treatments. Additionally, the expression of multiple genes encoding enzymes with antioxidant activity, including PODs and SODs, was induced, which plays a pivotal role in the mitigation of continuous ROS production. Furthermore, we observed that AS and transcriptional regulation modulate distinct pathways. We also found that the expression of genes encoding key transcription factors (TFs) was highly induced by cold stress and that some of the mRNAs encoding these key TFs were differentially spliced. This dataset provides comprehensive transcriptional and post-transcriptional profiles of the response to cold stress in trifoliate orange that may help to identify genes that contribute to cold tolerance in citrus.

Gene expression and soluble sugar accumulation in perennial fruits

Abstract Soluble sugars primarily contribute to fruit flavouring and are crucial for fruit quality. Carbohydrate accumulation in fruits is a multifaceted process that can be influenced by their biosynthesis capacity, sink strength, homeostasis, and vacuolar storage ability. Moreover, total soluble sugar contents in fruits also vary among different varieties/species and environmental conditions. Numerous studies have elucidated the carbohydrate regulatory mechanism in fruits; however, there is a knowledge gap regarding the most important contributor to soluble sugar accumulation in perennial fruits. Here, we briefly discussed the recent advances, including carbohydrate long-distance transportation, metabolism and vacuolar storage, and transcript factors for soluble sugar accumulation in fruits. Most importantly, we elucidated that the sink strength in fruit is the most crucial factor that can trap more soluble sugars by maintaining continuous unloading to fruit by genes of cell wall invertase; moreover, genes of sucrose transporters/pyrophosphatase play key roles in vacuolar storage of soluble sugars in perennial fruits. This review delivers a comprehensive summary of recent findings for soluble sugar regulation and fruit quality improvement, which may facilitate sugar optimisation in fruit crops for enhanced fruit quality.