Levels In Leaf Research Articles

Characterization of Superoxide Dismutase (SOD) Gene Family and Their Responses to Salinity Stress and Fruit Development in Octoploid Strawberry

Superoxide dismutases (SODs), as the first line of defense against reactive oxygen species (ROS), play an essential role in protecting plants from adverse elicitors during plant growth and development. However, little is known about the SOD gene family and their response to salinity stress and fruit development in cultivated strawberries (Fragaria × ananassa). In this study, 32 SOD genes consisting of 16 Cu/ZnSODs, 11 FeSODs, and 5 MnSOD were identified, which presented three well-resolved clades in the phylogenetic tree. Each clade had similar motifs, and exon–intron structures, which in turn supported the evolutionary classification. Cis-acting element analysis suggested that FaSOD genes might be involved in the plant response to abiotic and biotic stresses, hormones, and light. The analysis of previously published transcriptome data revealed that FaSOD genes are expressed variably under salt stress. Among these SODs, FaMSD5 was expressed at relatively high levels in strawberry root and leaf, and its transcript abundance significantly increased after salt treatment. Some transcription factors related to photomorphogenesis, hormone signaling pathways, and hyperosmotic salinity response were predicted to bind to the FaMSD5 promoter. These outcomes implied that FaMSD5 might play an important role in protection against salt stress. In addition, the comprehensive transcriptome analysis of FaSOD genes in strawberry fruit showed that almost all FaCSDs and FaMSDs were more highly expressed than FaFSDs at different developmental stages, and the expression patterns of FaCSD1, FaCSD2, FaCSD7, FaCSD8, and FaCSD10 suggested that they were likely to be involved in fruit development and ripening. This study provides a basis for further exploration of the function of the FaSOD gene family in strawberry and provides candidate FaSOD genes for enhancing salinity tolerance and regulating fruit development and ripening.

Nutrimental modifications in blueberry (Vaccinium corymbosum L.) caused by vanadium supply

Blueberry plants prosper in acid environments with pH 4.5, condition that enhances vanadium (V) bioavailability. In different species, literature reports nutrimental modifications caused by V, nevertheless in blueberry plants this effect remains unknown. This study assessed the impact of six vanadium (V) doses in nutrient solutions (0, 20, 40, 80, 160 µM) and as foliar sprays (20 µM) on blueberry plants, employing a completely randomized experimental design with three replicates. At 66 days after applying the treatments, nutriments concentrations in leaves, stems and roots of each plant were determinate. Except for N, V modified nutrimental concentrations in at least one plant organ. V applied to foliage benefits Mn (67%) in leaf, as Ca (56%), Mg (40%), B (26%) and Mn (46%) did in stems and P (50%) in roots. No matter V concentration in solution, P (51%), Fe (270%) and Cu (230%) in roots are enhanced, but Mo it is reduced up to 6 times. The use of 160 µM of V in solutions increases Mg (40%) concentrations in stems, the same happened in Ca (32%) and Zn (47%) in roots but reduced K (35%) in this organ. V applied from 0 to 160 µM in solution increases 3, 64, 225 times V concentration in leaf, stem and roots respectively. These results show that V applications in solution benefits P levels in leaf, Ca and Mg in stem, P, Ca and Mg in root; while foliar spray enhances K, Ca, Mg concentration in stem and Mg in root.

The effect of balanced N, P, K, Ca, Mg fertilizer on soil and leaf nutrient and its correlation with growth and corn yield (Zea mays L.)

Fertilization in agricultural cultivation is important in increasing the supply of necessary nutrients for plants to achieve high yield and quality. This study aims to examine the balance of N,P,K,Ca, and Mg against nutrients in soil and plants and its correlation with the growth and yield of corn. There were 9 treatments of N, P, K, Ca, Mg fertilizer balance used, namely: control (A) and 1: 1: 1: 0: 0 (B); 0.25: 0.25: 0.25: 1: 1 (C); 0.5: 0.5: 0.5: 1: 1 (D); 0.75: 0.75: 0.75: 1: 1 (E); 1: 1:1: 1: 1 (F); 0.75: 0.75: 0.75: 0.25: 0.25 (G); 0.75: 0.75: 0.75: 0.5: 0.5 (H); 0.75: 0.75: 0.75: 0.75: 0.75 (I). Parameters observed included nutrients N, P, K, Ca, and Mg in soil and leaf, plant height, stem diameter, number of leaves, cob weight with and without husks, and cob length and diameter. The results showed that nutrient balance significantly affected nutrient levels in soil and leaf, plant growth, and yield of corn. N, P, K, Ca, Mg Fertilizer application with ratio 0.5: 0.5: 0.5: 1: 1 (D) increased soil N 100%, P 40%, K 108.33%, Ca 28.08%, Mg 30.17% higher than the control and plant leaf N, P, K, Ca, Mg about 101.60%, 12.50%, 10.13%, 50.98%, 101.41% respectively, thus providing higher growth and yield. There was a significant correlation between plant height with leaf N and K, stem diameter correlated with leaf Ca, and number of leaves correlated with Mg in corn leaf. Meanwhile, yield correlated with P.

Characterization of FBA genes in potato (Solanum tuberosum L.) and expression patterns in response to light spectrum and abiotic stress.

Fructose-1, 6-bisphosphate aldolase (FBA) plays vital roles in plant growth, development, and response to abiotic stress. However, genome-wide identification and structural characterization of the potato (Solanum tuberosum L.) FBA gene family has not been systematically analyzed. In this study, we identified nine StFBA gene members in potato, with six StFBA genes localized in the chloroplast and three in the cytoplasm. The analysis of gene structures, protein structures, and phylogenetic relationships indicated that StFBA genes were divided into Class I and II, which exhibited significant differences in structure and function. Synteny analysis revealed that segmental duplication events promoted the expansion of the StFBA gene family. Promoter analysis showed that most StFBA genes contained cis-regulatory elements associated with light and stress responses. Expression analysis showed that StFBA3, StFBA8, and StFBA9 showing significantly higher expression levels in leaf, stolon, and tuber under blue light, indicating that these genes may improve photosynthesis and play an important function in regulating the induction and expansion of microtubers. Expression levels of the StFBA genes were influenced by drought and salt stress, indicating that they played important roles in abiotic stress. This work offers a theoretical foundation for in-depth understanding of the evolution and function of StFBA genes, as well as providing the basis for the genetic improvement of potatoes.

ApCPS2 contributes to medicinal diterpenoid biosynthesis and defense against insect herbivore in Andrographis paniculata

Kalmegh (Andrographis paniculata) spatiotemporally produces medicinally-important ent-labdane-related diterpenoids (ent-LRDs); andrographolide (AD), 14-deoxy-11,12-didehydroandrographolide (DDAD), neoandrographolide (NAD). ApCPS1 and ApCPS2, the ent-copalyl pyrophosphate (ent-CPP)-producing class II diterpene synthases (diTPSs) were identified, but their contributions to ent-CPP precursor supply for ent-LRD biosynthesis were not well understood. Here, we characterized ApCPS4, an additional ent-CPP-forming diTPS. Further, we elucidated in planta function of the ent-CPP-producing diTPSs (ApCPS1,2,4) by integrating transcript-metabolite co-profiles, biochemical analysis and gene functional characterization. ApCPS1,2,4 localized to the plastids, where diterpenoid biosynthesis occurs in plants, but ApCPS1,2,4 transcript expression patterns and ent-LRD contents revealed a strong correlation of ApCPS2 expression and ent-LRD accumulation in kalmegh. ApCPS1,2,4 upstream sequences differentially activated β-glucuronidase (GUS) in Arabidopsis and transiently-transformed kalmegh. Similar to higher expression of ApCPS1 in kalmegh stem, ApCPS1 upstream sequence activated GUS in stem/hypocotyl of Arabidopsis and kalmegh. However, ApCPS2,4 upstream sequences weakly activated GUS expression in Arabidopsis, which was not well correlated with ApCPS2,4 transcript expression in kalmegh tissues. Whereas, ApCPS2,4 upstream sequences could activate GUS expression at a considerable level in kalmegh leaf and roots/calyx, respectively, suggesting the involvement of transcriptional regulator(s) of ApCPS2,4 that might participate in kalmegh-specific diterpenoid pathway. Interestingly, ApCPS2-silenced kalmegh showed a drastic reduction in AD, DDAD and NAD contents and compromised defense against insect herbivore Spodoptera litura. However, ent-LRD contents and herbivore defense in ApCPS1 or ApCPS4-silenced plants remained largely unaltered. Overall, these results suggested an important role of ApCPS2 in producing ent-CPP for medicinal ent-LRD biosynthesis and defense against insect herbivore.

Identification and functional analysis of jasmonic acid signaling repressor McJAZ8 gene in Mentha canadensis

Mentha canadensis, as a plant with medicinal and culinary uses, holds significant economic value. Jasmonic acid signaling repressor JAZ protein has a crucial role in regulating plant response to adversity stresses. The M. canadensis McJAZ8 gene is cloned and analyzed for protein characterization, protein interactions, and expression patterns, so as to provide genetic resources for molecular breeding of M. canadensis for stress tolerance. This experiment will analyze the protein structural characteristics, subcellular localization, protein interactions, and gene expression of McJAZ8 using bioinformatics, yeast two-hybrid(Y2H), transient expression in tobacco leaves, qRT-PCR, and other technologies. The results show that:(1)The full length of the McJAZ8 gene is 543 bp, encoding 180 amino acids. The McJAZ8 protein contains conserved TIFY and Jas domains and exhibits high homology with Arabidopsis thaliana AtJAZ1 and AtJAZ2.(2)The McJAZ8 protein is localized in the nucleus and cytoplasm.(3)The Y2H results show that McJAZ8 interacts with itself or McJAZ1/3/4/5 proteins to form homologous or heterologous dimers.(4)McJAZ8 is expressed in different tissue, with the highest expression level in young leaves. In terms of leaf sequence, McJAZ8 shows the highest expression level in the fourth leaf and the lowest expression level in the second leaf.(5) In leaves and roots, the expression of McJAZ8 is upregulated to varying degrees under methyl jasmonate(MeJA), drought, and NaCl treatments. The expression of McJAZ8 shows an initial upregulation followed by a downregulation pattern under CdCl_2 treatment. In leaves, the expression of McJAZ8 tends to gradually decrease under CuCl_2 treatment, while in roots, it initially decreases and then increases before decreasing again. In both leaves and roots, the expression of McJAZ8 is downregulated to varying degrees under AlCl_(3 )treatment. This study has enriched the research on jasmonic acid signaling repressor JAZ genes in M. canadensis and provided genetic resources for the molecular breeding of M. canadensis.

Peach LAZY1 and DRO1 protein-protein interactions and co-expression with PRAF/RLD family support conserved gravity-related protein interactions across plants.

IGT/LAZY proteins play a central role in determining gravitropic set point angle and orientation of lateral organs across plant species. Recent work in model systems has demonstrated that interactions between IGT/LAZY proteins and BREVIS RADIX (BRX)-domain containing proteins, such as PH, RCC1, AND FYVE/RCC1-LIKE DOMAIN (PRAF/RLD), and BREVIS RADIX LIKE (BRXL) family members, are mechanistically important for setting gravitropic set point angle. Here, we identified peach PRAF/RLD proteins as interactors of the peach IGT/LAZY proteins PpeLAZY1 and DEEPER ROOTING 1 (PpeDRO1) from a yeast-two-hybrid screen. We also show that the BRX domains of these interacting proteins have high sequence similarity with PRAF/RLD and BRX family proteins from rice and Arabidopsis. Further, PpeLAZY1 and the peach PRAF/RLD interactors are all expressed at relatively high levels in leaf, meristem, and shoot tip tissues. Together, this evidence supports the importance and conservation of IGT/LAZY-BRX-domain interactions, which underlie setting gravitropic set point angle across angiosperms.

Assessment of Phenolic Composition, Antioxidant Potential, Antimicrobial Properties, and Antidiabetic Activity in Extracts Obtained from Schinus molle L. Leaves and Fruits.

The current research centers on exploring the antioxidant, antimicrobial, and antidiabetic features of Schinus molle L. grown in Turkey. Quantitative analysis of chlorogenic acid, caffeic acid, and hyperoside levels in leaf, ripe fruit, and raw fruit extracts was conducted using High-Performance Liquid Chromatography (HPLC) in a 70% methanol-water mixture. Among the extracts, the methanol extract from ripe fruits displayed the highest chlorogenic acid concentration, measuring at 2.040% ± 0.172% standard deviation (SD). Moreover, analysis of their total phenolic and flavonoid contents was carried out. Antioxidant power was assessed through different chemical assays, together with their antimicrobial and anti-diabetic properties. The results of DPPH (2,2-Diphenyl-1-picrylhydrazyl), ABTS (2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and reducing power assays showed that leaf and ripe fruit alcoholic extract exhibited peak performance. While the MIC ( minimum inhibitory concentration) values of the extracts were determined to have moderate bactericidal effects on Staphylococcus aureus, Escherichia coli, and Candida albicans it was observed that none of the extracts displayed biofilm inhibition. The inhibition percentage of α-glucosidase enzyme activity for the methanol extract of raw fruits was determined to be 99.11 ± 1.61. In diabetic β-TC cells, glucose level was measured as 129 ± 2.03 mg/dL, and insulin amount was measured as 37.2 ± 0.02 mg/dL. The findings of our study seem to have important implications for future research, as Schinus molle L. may be a potential pharmaceutical candidate with important pharmacological activities.

Synergistic effect of silicon and arbuscular mycorrhizal fungi reduces cadmium accumulation by regulating hormonal transduction and lignin accumulation in maize

Cadmium (Cd) stress causes serious damage to plants, inducing various physiological and biochemical disruptions that lead to reduced plant biomass and compromised growth. The study investigated the combined effects of silicon (Si) and arbuscular mycorrhizal fungi (AMF) on mitigating Cd stress in plants, revealing promising results in enhancing plant tolerance to Cd toxicity. Under Cd stress, plant biomass was significantly reduced (−33% and −30% shoot and root dry weights) as compared to control. However, Si and AMF application ameliorated this effect, leading to increased shoot and root dry weights (+47% and +39%). Furthermore, Si and AMF demonstrated their potential in reducing the relative Cd content (−43% and −36% in shoot and root) in plants and positively influencing plant colonization (+648%), providing eco-friendly and sustainable strategies to combat Cd toxicity in contaminated soils. Additionally, the combined treatment in the Cd-stressed conditions resulted in notable increases in saccharide compounds and hormone levels in both leaf and root tissues, further enhancing the plant's resilience to Cd-induced stress. Si and AMF also played a vital role in positively regulating key lignin biosynthesis genes and altering lignin-related metabolites, shedding light on their potential to fortify plants against Cd stress. These findings underscore the significance of Si and AMF as promising tools in addressing Cd toxicity and enhancing plant performance in Cd-contaminated environments.

Composition and localization of the leaf waxes in seven epiphytic Tillandsia species

Air plants (Tillandsia) rely on leaves to absorb water and nutrients, and waxy trichomes on the leaf surface play an important role in this process. However, there is no definite information on the waxy components of air plant leaves or whether they are located on the trichomes. In this study, SEM and GC-MS were used to analyze the leaf surface structure and waxy components in seven Tillandsia species. The results showed that the waxy components included hydrocarbons, alcohols, ketones, and esters. Only T. brachycaulos contained low levels of acids. There were significant differences in the levels of leaf waxy components among different species and differences in the levels of specific components. The amount of waxy component in the seven air plant species was ordered as follows: T. ionantha > T. brachycaulos > T. velutina > T. usneoides > T. medusa > T. stricta > T. streptophylla. Correlation analysis revealed that the total waxy component level was significantly positively correlated with the total trichome area. After trichome wing cells were manually removed from T. brachycaulos and T. velutina, the levels of various chemical components significantly decreased. The levels of various chemical components in trichomes accounted for more than 50% of the total corresponding level in the entire leaf. These results indicated that the waxy components in air plant leaves were mainly located on trichomes.

Transcriptome sequencing analyses uncover mechanisms of citrus rootstock seedlings under waterlogging stress.

Citrus plants are sensitive to waterlogging, which can cause yield reduction. Their production heavily depends on the rootstock being used for grafting of scion cultivars, and the rootstock is the first organ to be affected by waterlogging stress. However, the underlying molecular mechanisms of waterlogging stress tolerance remain elusive. In this study we investigated the stress response of two waterlogging-tolerant citrus varieties (Citrus junos Sieb ex Tanaka cv. Pujiang Xiangcheng and Ziyang Xiangcheng), and one waterlogging-sensitive variety (red tangerine) at the morphological, physiological, and genetic levels in leaf and root tissues of partially submerged plants. The results showed that waterlogging stress significantly decreased the SPAD value and root length but did not obviously affect the stem length and new root numbers. The malondialdehyde (MDA) content and the enzyme activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), and catalase (CAT) were enhanced in the roots. The RNA-seq analysis revealed that the differentially expressed genes (DEGs) were mainly linked to 'cutin, suberine, and wax biosynthesis', 'diterpenoid biosynthesis', and 'glycerophospholipid metabolism' in the leaves, whereas were linked to 'flavonoid biosynthesis', 'biosynthesis of secondary metabolites and metabolic pathways' in the roots. Finally, we developed a working model based on our results to elucidate the molecular basis of waterlogging-responsive in citrus. Therefore, our data obtained in this study provided valuable genetic resources that will facilitate the breeding of citrus varieties with improved waterlogging tolerance.

Functional and evolutionary study of MLO gene family in the regulation of Sclerotinia stem rot resistance in Brassica napus L.

BackgroundOilseed rape (Brassica napus L.) is known as one of the most important oilseed crops cultivated around the world. However, its production continuously faces a huge challenge of Sclerotinia stem rot (SSR), a destructive disease caused by the fungus Sclerotinia sclerotiorum, resulting in huge yield loss annually. The SSR resistance in B. napus is quantitative and controlled by a set of minor genes. Identification of these genes and pyramiding them into a variety are a major strategy for SSR resistance breeding in B. napus.ResultsHere, we performed a genome-wide association study (GWAS) using a natural population of B. napus consisting of 222 accessions to identify BnaA08g25340D (BnMLO2_2) as a candidate gene that regulates the SSR resistance. BnMLO2_2 was a member of seven homolog genes of Arabidopsis Mildew Locus O 2 (MLO2) and the significantly SNPs were mainly distributed in the promoter of BnMLO2_2, suggesting a role of BnMLO2_2 expression level in the regulation of SSR resistance. We expressed BnMLO2_2 in Arabidopsis and the transgenic plants displayed an enhanced SSR resistance. Transcriptome profiling of different tissues of B. napus revealed that BnMLO2_2 had the most expression level in leaf and silique tissues among all the 7 BnMLO2 members and also expressed higher in the SSR resistant accession than in the susceptible accession. In Arabidopsis, mlo2 plants displayed reduced resistance to SSR, whereas overexpression of MLO2 conferred plants an enhanced SSR resistance. Moreover, a higher expression level of MLO2 showed a stronger SSR resistance in the transgenic plants. The regulation of MLO2 in SSR resistance may be associated with the cell death. Collinearity and phylogenetic analysis revealed a large expansion of MLO family in Brassica crops.ConclusionOur study revealed an important role of BnMLO2 in the regulation of SSR resistance and provided a new gene candidate for future improvement of SSR resistance in B. napus and also new insights into understanding of MLO family evolution in Brassica crops.

Insecticide residue analysis on vegetable crops through Rapid Bioassay of Pesticide Residue (RBPR) technique in Nepal

Insecticides applied on food crops and vegetables reduce the pest population and leave chemical residues that may result in serious health consequences. In Nepalese context, farmers use pesticides repeatedly to get rid of pests and also don’t consider the waiting period. The study was conducted to evaluate the amount of pesticide residue after application of different organophosphate and carbamate insecticides in vegetable crops. Five insecticides were used in seven different combinations (Dimethoate, Malathion, dichlorvos, Chlorpyriphos, Dimethoate + dichlorvos, Malathion + Chlorpyriphos and Carbofuran) and applied in mustard leaves and broccoli. The residues were assessed using the “Rapid Bioassay of Pesticide Residue technique”. Results exhibited that Chlorpyriphos treated mustard leaves were edible in 3 DAA (Days after application) and in 6 DAA when sticker was applied with treatment. With or without sticker Dimethoate followed by Malathion applied mustard leaves were edible in 6 DAA. With or without sticker Dichlorvos took longest (12 DAA) to reach the safe limits for mustard leaves. In contrary the Dichlorvos treated broccoli was edible in 3 DAA but took 6 DAA when sticker was applied. Malathion treated broccoli, with and without sticker, was edible in 6 DAA. For both crops Carbofuran exhibited anomalous nature showing lower residue level in the beginning and higher later. When both vegetables were applied treatments with stickers, they showed significantly higher residue and took longer time to reach edible limit. The applied insecticides took relatively longer to reach safe level in mustard leaf as compared to broccoli. The study suggests use of Chlorpyriphos for mustard leaves and Malathion for broccoli with at least 6 days of waiting period, with or without use of sticker.

Proline synthesis and catabolism-related genes synergistically regulate proline accumulation in response to abiotic stresses in grapevines

Proline is an important osmotic regulator for plants under abiotic stresses. Proline accumulation is regulated by various enzymes, while genes encoding these enzymes have not been fully investigated in grapevines. In this study, we identified four proline biosynthesis-related genes (P5CS1, P5CS2, P5CR and OAT) and two proline catabolism-related genes (PDH and P5CDH) from grapevines, and conducted bioinformatics analysis including protein characteristic, gene structure, phylogenetic relationship and cis-acting element of promoters. Promoter analysis found that cis-acting elements related to stress and phytohormone responsiveness were present in the promoters of these genes. Tissue-specific expression analysis of these genes indicated that P5CS2, OAT and PDH expressed highly in flower, and P5CS1, P5CR and P5CDH had highest expression levels in tendril, berry and leaf respectively. Expression patterns of these genes under abiotic stresses revealed that P5CS1, OAT and PDH could be significantly induced by salt, dehydration, PEG and H2O2 treatments, and P5CDH was significantly suppressed under these stress treatments. By measuring proline accumulation in grapevines, we found that proline content dramatically increased after treatments of salt, dehydration, PEG and H2O2. Our results revealed the molecular responses (especially P5CS1, OAT, PDH and P5CDH) in the proline metabolism pathway to osmotic and oxidative stresses in grapevines, demonstrating that proline synthesis and proline catabolism synergistically regulate proline accumulation in response to abiotic stresses.

Using Proline Synthetase and BT gene to improve soybean (Glycine max) drought and insect resistance

AbstractIn agricultural production, developing a high yield with good quality and a stable yield are significant goals. To meet the aim of agriculture and produce high‐yielding, drought‐resistant and insect‐resistant varieties are preferred in the breeding of soybean. The pCAMBIA3301 plasmid was used as the base vector, and an overexpression vector containing the proline synthase gene Fu‐1 was recombined. The Fu‐1 gene was genetically transformed into the high‐generation (T7 generation) containing CryAb13‐1 transgene via the pollen tube channel method. Soybean was used to create a novel material that is insect resistant as well as drought‐resistant. Traditional polymerase chain reaction (PCR) identification was used to identify the transformed T2 generation plants, and Southern blot hybridization (SBH) and fluorescence quantitative PCR were used for detection. The test results showed that there were 10 positive plants in the T2 generation plants that were detected by common PCR. SBH results showed that Fu‐1 and CryAb13‐1 genes were integrated into soybean in the type of a single copy. The expression levels of Fu‐1 and CryAb13‐1 genes were variable in different tissues, according to the results of fluorescence quantitative PCR. In soybean roots, stems and leaves, the average expression levels of the Fu‐1 gene were 4.43, 1.86 and 2.51, respectively. CryAb13‐1 gene was expressed in roots. The average expression levels in roots, stem and leaf were 1.80, 1.38 and 5.28, respectively. The highest expression level was found in leaves in different soybean tissues. The indoor drought resistance identification showed that the water content, relative conductivity, POD activity, SOD activity, MDA and Pro content of the transformed plants after seven days of stress were significantly changed, and the drought resistance ability was significantly improved. Hence, we obtained a new soybean that can resist both drought and insect.

Selenium Application Decreases the Enrichment and Human Exposure Risk of Cadmium in the Leaf of Jute (Corchorus capsularis L.) Planted in Uncontaminated Purple Soil

The effects of soil selenium (Se) application on the enrichment and human exposure risk of heavy metals in the jute (Corchorus capsularis L.) leaf have attracted extensive attention. The jute was planted with or without soil Se addition for 265 days. The jute leaf was harvested seven times during the experiment to determine the content of lead (Pb), cadmium (Cd), and Se. The results showed that the enrichment ability ranked Cd > Se > Pb. Cd in the jute leaf exceeded the average pollutant limit in GB2762-2017 by 1.37 times without Se application. The Se application is conducive to an increase of Se by 88.11–202.79%, contrarily reducing Cd by 35.40–38.32% and Pb by 9.58–26.57%. In general, the risk quotients (HQ) of Cd and Pb were decreased and less than 1 with Se treatment. Thus, the human exposure risk of Cd and Pb is negligible when ingesting the jute leaf via diet. It is suggested that Se can be applied to inhibit the enrichment of Cd and Pb in the jute production process to reduce the potential exposure risk of Cd and Pb to the human body and increase economic and nutritional values by raising Se levels in the jute leaf.

Transcriptome analysis reveals the genes involved in S-alk(en)ylcysteine sulfoxide biosynthesis and its biosynthetic location in postharvest chive (Allium schoenoprasum L.)

The biosynthetic mechanism of S-alk(en)ylcysteine sulfoxides (CSOs), a flavor precursor and nonvolatile medicinal compound in chive is still poorly understood. In the present study, transcriptomic analysis was used to investigate the biosynthetic mechanism of S-alk(en)ylcysteine sulfoxides (CSOs) in green leaves of postharvest chive stored under normal temperature (20 °C) for 5 d and low-temperature (3 °C) for 12 d. The de novo assembly of the transcriptome enabled the identification of unigenes involved in the sulfur assimilation and CSOs biosynthesis. The RNA-seq data showed that the unigenes related to sulfur assimilation were down-regulated during storage under 20 °C and 3 °C. The low temperature did not affect cysteine biosynthesis and the expression of γ-glutamyl transpeptidase (GGT) and flavin-containing monooxygenase (FMO) involved in CSOs biosynthesis; nonetheless, it prolonged CSOs synthesis by sustaining the chive quality during the storage period. The qPCR data revealed that the expressions of genes related to sulfur assimilation were mainly in the white stalk. In contrast, CSOs biosynthetic genes had higher expression levels in green leaf. The results indicate the CSOs were mainly synthesized in green leaf while cysteine, the primary substrate for CSOs synthesis, was from de novo synthesis and proteolysis. The study presents discrete evidence that CSOs biosynthesis in postharvest chives occurs in green leaves and is translocated to the white stalk for storage.

CeO2 Nanoparticles Seed Priming Increases Salicylic Acid Level and ROS Scavenging Ability to Improve Rapeseed Salt Tolerance.

Soil salinity is a major issue limiting efficient crop production. Seed priming with nanomaterials (nanopriming) is a cost‐effective technology to improve seed germination under salinity; however, the underlying mechanisms still need to be explored. Here, polyacrylic acid coated nanoceria (cerium oxide nanoparticles) (PNC, 9.2 nm, −38.7 mV) are synthesized and characterized. The results show that under salinity, PNC priming significantly increases rapeseed shoot length (41.5%), root length (93%), and seedling dry weight (78%) compared to the no‐nanoparticle (NNP) priming group. Confocal imaging results show that compared with NNP group, PNC priming significantly reduces reactive oxygen species (ROS) level in leaf (94.3% of H2O2, 56.4% of •O2 −) and root (38.4% of H2O2, 41.3% of •O2 −) of salt stressed rapeseed seedlings. Further, the results show that compared with the NNP group, PNC priming not only increases salicylic acid (SA) content in shoot (51.3%) and root (78.4%), but also upregulates the expression of SA biosynthesis related genes in salt stressed rapeseed. Overall, PNC nanopriming improved rapeseed salt tolerance is associated with both the increase of ROS scavenging ability and the increase of salicylic acid. The results add more information to understand the complexity of mechanisms behind nanoceria priming improved plant salt tolerance.

Potassium deficiency stress tolerance in peanut (Arachis hypogaea) through ion homeostasis, activation of antioxidant defense, and metabolic dynamics: Alleviatory role of silicon supplementation

Potassium (K) scarcity of arable land is one of the important factors that hamper the growth of the plants and reduce yield worldwide. In the current study, we examine the physiological, biochemical, and metabolome response of Arachis hypogaea (GG7 genotype: fast-growing, tall, early maturing, and high yielding) under low K either solitary or in combination with Si to elucidate the ameliorative role of Si. The reduced fresh and dry biomass of peanut and photosynthetic pigments content was significantly alleviated by Si. Si application did not affect the leaf and stem K+, although it enhanced root K+ in K-limitation, which is probably due to up-regulated expression of genes responsible for K uptake. Si improves the potassium use efficiency in K-limitation as compared to control. K-deficiency increased MDA, O2•−, and H2O2 levels in leaf and root of peanut. Si improved/maintained the activity of antioxidative enzymes, which significantly lowered the ROS accumulation in K-limitation. The AsA/DHA and GSH/GSSG ratio was approximately unaffected in both leaf and root, suggesting the maintained cellular redox potential in K-starved peanut. Si promotes accumulation of sugars and sugar alcohols, phytohormones indicating their probable involvement in signal transduction, osmotic regulation, and improvement of stress tolerance. Down-regulation of aspartic acid and glutamic acid while up-regulation of lysine, histidine, and arginine could maintain charge balance in K-deprived peanut. The significant accumulation of polyphenols under K limitation supplemented with Si suggests the role of polyphenols for ROS scavenging. Our results demonstrated that Si as a beneficial element can mitigate K-nutrient toxicity and improve KUE of peanut under K-limitation conditions. Moreover, our results demonstrate that Si application can improve crop yield, quality, and nutrient use efficiency under nutrient limitation conditions.

Arbuscular mycorrhizal fungus and organics substrates effect on bean plant morphology and minerals

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts that require a host plant (tramp) and support (substrates) to be applied as bio-fertilizers in agriculture. The objective of this study is to assess eight native AMF consortia of semi-arid zones (C1-ART, C2-GEC, C3-PAR, C4-VIE, C5-CUC, C6-SAC, C7-SAB, and C8-MUZ) and their reproduction response in three organic substrates: coffee pulp (CP), bovine manure (BM) and sugarcane bagasse (SB) on bean Phaseolus vulgaris. Plant height, stem diameter, number of leaves, root length, fresh and dry biomass, and mineral content in root were measured. The organic substrates (CP and BM) and C5-CUC and C8-MUZ consortia increased plant height, root length, and total fresh and dry biomass considerably. After day 75 of inoculation, root colonization oscillated from 5.7% in C8-MUZ to 46.1% in C2-GEC and C4-VIE; the greatest number of spores (201) was obtained in CP substrate in a 100-g sample. N, P, K, Ca, Mg, Fe, Zn, Cu, and Mn contents in root and leaves were signif icantly high (P ≤ 0.001). To conclude, native AMF inoculation and substrates had positive effects on biomass content and nutrient levels in leaf and root with the C2-GEC and C3-PAR consortia and CP and BM substrates, which produced better effects in beans, making them a biofertilization alternative in agricultural crops.