Wheat lesion mimic homology gene TaCAT2 enhances plant resistance to biotic and abiotic stresses.

Lesion mimic mutants (LMMs) refer to the spontaneous formation of disease-like spots on leaves without any obvious pathogen infection. The LMM genes can regulate plant immunity, thus promoting the defense of crops against pathogens. However, there is a lack of systematic understanding of the regulatory mechanism of LMMs in wheat. This study identified a wheat LMM TaCAT2, a homolog of the Arabidopsis CAT2. The prediction of the cis-regulatory element revealed that TaCAT2 was involved in the response of plants to various hormones and stresses. RT-qPCR analysis indicated that TaCAT2 was significantly up-regulated by NaCl, drought, and Fusarium graminearum infection. Fluorescence microscopy showed that the TaCAT2 was localized to the peroxisome. Overexpression of TaCAT2 enhanced plant resistance to Phytophthora infestation and F. graminearum by constitutionally activating SA and JA pathways. VIGS of TaCAT2 enhanced the sensitivity of wheat to F. graminearum. Further, TaCAT2 enhanced stress resistance by scavenging the excessive ROS and increasing the activities of antioxidative enzymes. This study lays the basis for the functional identification of TaCAT2 and its applicability in the disease resistance of wheat.

Genome-wide characterization and function analysis of ginger (Zingiber officinale Roscoe) ZoGRFs in responding to adverse stresses.

Growth-regulating factors (GRFs) play crucial roles in plant growth, development, hormone signaling, and stress response. Despite their significance, the roles of GRFs in ginger remain largely unknown. Herein, 31 ginger ZoGRFs were identified and designated as ZoGRF1-ZoGRF31 according to their phylogenetic relationships. All ZoGRFs were characterized as unstable, hydrophilic proteins, with 29 predicted to be located in the nucleus. Functional cis-elements related to growth and development were enriched in ZoGRF's promoter regions. RNA-seq and RT-qPCR analysis revealed that ZoGRF12, ZoGRF24, and ZoGRF28 were highly induced in various growth and development stages, displaying differential regulation under waterlogging, chilling, drought, and salt stresses, indicating diverse expression patterns of ZoGRFs. Transient expression analysis in Nicotiana benthamiana indicated that overexpressing ZoGRF28 regulated the transcription levels of salicylic acid, jasmonic acid, and pattern-triggered immunity-related genes, increased chlorophyll content and contributed to reduced disease lesions and an increased net photosynthetic rate. This research lays the foundation for further understanding the biological roles of ZoGRFs.

Structure, evolution, and roles of SWEET proteins in growth and stress responses in plants.

Carbohydrates are exported by the SWEET family of transporters, which is a novel class of carriers that can transport sugars across cell membranes and facilitate sugar's long-distance transport from source to sink organs in plants. SWEETs play crucial roles in a wide range of physiologically important processes by regulating apoplastic and symplastic sugar concentrations. These processes include host-pathogen interactions, abiotic stress responses, and plant growth and development. In the present review, we (i) describe the structure and organization of SWEETs in the cell membrane, (ii) discuss the roles of SWEETs in sugar loading and unloading processes, (iii) identify the distinct functions of SWEETs in regulating plant growth and development including flower, fruit, and seed development, (iv) shed light on the importance of SWEETs in modulating abiotic stress resistance, and (v) describe the role of SWEET genes during plant-pathogen interaction. Finally, several perspectives regarding future investigations for improving the understanding of sugar-mediated plant defenses are proposed.

Genome-Wide Identification of DUF668 Gene Family and Expression Analysis under F. solani, Chilling, and Waterlogging Stresses in Zingiber officinale.

The domains of unknown function (DUF) superfamilies contain proteins with conserved amino acid sequences without known functions. Among them, DUF668 was indicated widely involving the stress response of plants. However, understanding ZoDUF668 is still lacking. Here, 12 ZoDUF668 genes were identified in ginger by the bioinformatics method and unevenly distributed on six chromosomes. Conserved domain analysis showed that members of the same subfamily had similar conserved motifs and gene structures. The promoter region of ZoDUF668s contained the light, plant hormone and stress-responsive elements. The prediction of miRNA targeting relationship showed that nine ginger miRNAs targeted four ZoDUF668 genes through cleavage. The expression patterns of 12 ZoDUF668 genes under biotic and abiotic stress were analyzed using RT-qPCR. The results showed that the expression of seven ZoDUF668 genes was significantly downregulated under Fusarium solani infection, six ZoDUF668 genes were upregulated under cold stress, and five ZoDUF668 genes were upregulated under waterlogging stress. These results indicate that the ZoDUF668 gene has different expression patterns under different stress conditions. This study provides excellent candidate genes and provides a reference for stress-resistance research in ginger.

Multiple amino acid transporters as carriers load L-valine-phenazine-1-carboxylic acid conjugate into Ricinus sieve tubes for the phloem translocation.

Some transporters play important roles in the uptake and acropetal xylem translocation of vectorized agrochemicals. However, it is poorly understood the basipetally phloem-loading functions of transporters toward vectorized agrochemicals. Here, L-Val-PCA (L-valine-phenazine-1-carboxylic acid conjugate) uptake was demonstrated carrier-mediated. RcAAP2, RcANT7, and RcLHT1 showed a similarly up-regulated expression pattern from 62 transporter coding genes in Ricinus at 1 h after L-Val or L-Val-PCA treatment. Subcellular localization revealed that fusion RcAAP2-eGFP, RcANT7-eGFP and RcLHT1-eGFP proteins were expressed in the plasma membrane of mesophyll and phloem cells. Yeast assays found that RcAAP2, RcANT7, and RcLHT1 facilitated L-Val-PCA uptake. To further demonstrate the phloem-loading functions, using vacuum infiltration strategy, an Agrobacterium-mediated RNA interference (RNAi) protocol was constructed in seedlings. HPLC detection indicated that L-Val-PCA phloem sap concentrations were significantly decreased 54.5 %, 27.6 %, and 41.6 % after silencing for 72 h and increased 48.3 %, 52.6 %, and 52.4 % after overexpression, respectively. In conclusion, the plasma membrane-located RcAAP2, RcANT7, and RcLHT1 can loaded L-Val-PCA into Ricinus sieve tubes for the phloem translocation, which may aid in the utilization of transporters and molecular design of phloem-mobile fungicides target root or vascular pathogens.

Genome-Wide Identification and Expression Analysis of the SWEET Gene Family in Capsicum annuum L.

Sugars will eventually be exported transporters (SWEETs) are a novel class of sugar transport proteins that play a crucial role in plant growth, development, and response to stress. However, there is a lack of systematic research on SWEETs in Capsicum annuum L. In this study, 33 CaSWEET genes were identified through bioinformatics analysis. The Ka/Ks analysis indicated that SWEET genes are highly conserved not only among peppers but also among Solanaceae species and have experienced strong purifying selection during evolution. The Cis-elements analysis showed that the light-responsive element, abscisic-acid-responsive element, jasmonic-acid-responsive element, and anaerobic-induction-responsive element are widely distributed in the promoter regions of CaSWEETs. The expression pattern analysis revealed that CaSWEETs exhibit tissue specificity and are widely involved in pepper growth, development, and stress responses. The post-transcription regulation analysis revealed that 20 pepper miRNAs target and regulate 16 CaSWEETs through cleavage and translation inhibition mechanisms. The pathogen inoculation assay showed that CaSWEET16 and CaSWEET22 function as susceptibility genes, as the overexpression of these genes promotes the colonization of pathogens, whereas CaSWEET31 functions as a resistance gene. In conclusion, through systematic identification and characteristic analysis, a comprehensive understanding of CaSWEET was obtained, which lays the foundation for further studies on the biological functions of SWEET genes.

Plant Regeneration via Organogenesis in Jerusalem Artichokes and Comparative Analysis of Endogenous Hormones and Antioxidant Enzymes in Typical and Atypical Shoots.

The Jerusalem artichoke (Helianthus tuberosus) is a tuberous plant with considerable nutrient and bioactive compounds. The optimization of the in vitro clonal propagation protocol is critical for large-scale reproduction and biotechnological applications of Jerusalem artichoke production. In this work, in vitro plant regeneration from the stem nodes of the Jerusalem artichoke via direct organogenesis is presented. In the shoot induction stage, the stem segments produced more shoots with vigorous growth on MS medium containing 0.5 mg/L 6-benzylaminopurine (6-BA). The concentrations of 6-BA and gibberellic acid (GA3) were both optimized at 0.5 mg/L for shoot multiplication, and the combination of 0.05 mg/L indole-3-butyric acid (IBA) and 0.05 mg/L 1-naphthylacetic acid (NAA) was the most responsive for root induction, yielding the largest number of roots. The regenerated plantlets were successfully hardened at a 96% survival rate and vigorously grew in the field. The genetic stability of the regenerated plants was confirmed by flow cytometry and simple sequence repeat (SSR) analysis. However, 17.3% of shoots on the optimum shoot induction medium had withered leaves and excessive callus (atypical shoots), which greatly reduced the induction efficiency. Enzyme activity in the typical and atypical shoots was compared. The atypical shoots had significantly higher levels of endogenous indole-3-acetic acid (IAA) and abscisic acid (ABA), as well as increased activity of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), whereas the content of 6-BA, zeatin (ZT), and GA3 was significantly reduced. The activity of the three enzymes was positively correlated with the content of IAA and ABA, while being negatively correlated with that of 6-BA, ZT, and GA3. The results suggest that the poor growth of the atypical shoots might be closely related to the significant accumulation of endogenous IAA and ABA, thus significantly increasing antioxidant enzyme activity.

Double roles of light-harvesting chlorophyll a/b binding protein TaLhc2 in wheat stress tolerance and photosynthesis.

Light-harvesting chlorophyll a/b binding proteins are encoded by nucleus genes and widely involve in capturing light energy, transferring energy, and responding to various stresses. However, their roles in wheat photosynthesis and stress tolerance are largely unknown. Here, Triticum aestivumlight-harvesting chlorophyll a/b binding protein TaLhc2 was identified. It showed subcellular localization in chloroplast, contained light responsive cis-elements, and highly expressed in green tissues and down-regulated by multiple stresses. TaLhc2 promoted the colonization of hemi-biotrophic pathogen; further analysis showed that TaLhc2 strengthened BAX-induced cell death, enhanced the ROS accumulation, and up-regulated pathogenesis-related genes; those results suggested that TaLhc2 has adverse influence on host immunity and function as a susceptible gene, thus host decreased its expression when faced with pathogen infection. RT-qPCR results showed that TaLhc2 was down-regulated by drought and salt stresses, while TaLhc2 improved the ROS accumulation under the two stresses, suggesting TaLhc2 may participate in wheat responding to abiotic stress. Additionally, TaLhc2 can increase the content of total chlorophyll and carotenoid by 1.3 % and 2.9 %, increase the net photosynthetic rate by 18 %, thus promote plant photosynthesis. Conclusively, we preliminarily deciphered the function of TaLhc2 in biotic/abiotic stresses and photosynthesis, which laid foundation for its usage in wheat breeding.

Genome-Wide Identification, Characterization and Expression Analysis of the TaDUF724 Gene Family in Wheat (Triticum aestivum).

Unknown functional domain (DUF) proteins constitute a large number of functionally uncharacterized protein families in eukaryotes. DUF724s play crucial roles in plants. However, the insight understanding of wheat TaDUF724s is currently lacking. To explore the possible function of TaDUF724s in wheat growth and development and stress response, the family members were systematically identified and characterized. In total, 14 TaDUF724s were detected from a wheat reference genome; they are unevenly distributed across the 11 chromosomes, and, according to chromosome location, they were named TaDUF724-1 to TaDUF724-14. Evolution analysis revealed that TaDUF724s were under negative selection, and fragment replication was the main reason for family expansion. All TaDUF724s are unstable proteins; most TaDUF724s are acidic and hydrophilic. They were predicted to be located in the nucleus and chloroplast. The promoter regions of TaDUF724s were enriched with the cis-elements functionally associated with growth and development, as well as being hormone-responsive. Expression profiling showed that TaDUF724-9 was highly expressed in seedings, roots, leaves, stems, spikes and grains, and strongly expressed throughout the whole growth period. The 12 TaDUF724 were post-transcription regulated by 12 wheat MicroRNA (miRNA) through cleavage and translation. RT-qPCR showed that six TaDUF724s were regulated by biological and abiotic stresses. Conclusively, TaDUF724s were systematically analyzed using bioinformatics methods, which laid a theoretical foundation for clarifying the function of TaDUF724s in wheat.

Multi-Omics Reveals the Impact of Exogenous Short-Chain Fatty Acid Infusion on Rumen Homeostasis: Insights into Crosstalk between the Microbiome and the Epithelium in a Goat Model.

Emerging data have underscored the significance of exogenous supplementation of butyrate in the regulation of rumen development and homeostasis. However, the effects of other short-chain fatty acids (SCFAs), such as acetate or propionate, has received comparatively less attention, and the consequences of extensive exogenous SCFA infusion remain largely unknown. In our study, we conducted a comprehensive investigation by infusion of three SCFAs to examine their respective roles in regulating the rumen microbiome, metabolism, and epithelium homeostasis. Data demonstrated that the infusion of sodium acetate (SA) increased rumen index while also promoting SCFA production and absorption through the upregulation of SCFA synthetic enzymes and the mRNA expression of SLC9A1 gene. Moreover, both SA and sodium propionate infusion resulted in an enhanced total antioxidant capacity, an increased concentration of occludin, and higher abundances of specific rumen bacteria, such as "Candidatus Saccharimonas," Christensenellaceae R-7, Butyrivibrio, Rikenellaceae RC9 gut, and Alloprevotella. In addition, sodium butyrate (SB) infusion exhibited positive effects by increasing the width of rumen papilla and the thickness of the stratum basale. SB infusion further enhanced antioxidant capacity and barrier function facilitated by cross talk with Monoglobus and Incertae Sedis. Furthermore, metabolome and transcriptome data revealed distinct metabolic patterns in rumen contents and epithelium, with a particular impact on amino acid and fatty acid metabolism processes. In conclusion, our data provided novel insights into the regulator effects of extensive infusion of the three major SCFAs on rumen fermentation patterns, antioxidant capacity, rumen barrier function, and rumen papilla development, all achieved without inducing rumen epithelial inflammation. IMPORTANCE The consequences of massive exogenous supplementation of SCFAs on rumen microbial fermentation and rumen epithelium health remain an area that requires further exploration. In our study, we sought to investigate the specific impact of administering high doses of exogenous acetate, propionate, and butyrate on rumen homeostasis, with a particular focus on understanding the interaction between the rumen microbiome and epithelium. Importantly, our findings indicated that the massive infusion of these SCFAs did not induce rumen inflammation. Instead, we observed enhancements in antioxidant capacity, strengthening of rumen barrier function, and promotion of rumen papilla development, which were facilitated through interactions with specific rumen bacteria. By addressing existing knowledge gaps and offering critical insights into the regulation of rumen health through SCFA supplementation, our study holds significant implications for enhancing the well-being and productivity of ruminant animals.

Transcriptomic and physiological analyses reveal changes in secondary metabolite and endogenous hormone in ginger (Zingiber officinale Rosc.) in response to postharvest chilling stress.

Storing postharvest ginger at low temperatures can extend its shelf life, but can also lead to chilling injury, loss of flavor, and excessive water loss. To investigate the effects of chilling stress on ginger quality, morphological, physiological, and transcriptomic changes were examined after storage at 26 °C, 10 °C, and 2 °C for 24 h. Compared to 26 °C and 10 °C, storage at 2 °C significantly increased the concentrations of lignin, soluble sugar, flavonoids, and phenolics, as well as the accumulation of H2O2, O2-, and thiobarbituric acid reactive substances (TBARS). Additionally, chilling stress inhibited the levels of indoleacetic acid, while enhancing gibberellin, abscisic acid, and jasmonic acid, which may have increased postharvest ginger's adaptation to chilling. Storage at 10 °C decreased lignin concentration and oxidative damage, and induced less fluctuant changes in enzymes and hormones than storage at 2 °C. RNA-seq revealed that the number of differentially expressed genes (DEGs) increased with decreasing temperature. Functional enrichment analysis of the 523 DEGs that exhibited similar expression patterns between all treatments indicated that they were primarily enriched in phytohormone signaling, biosynthesis of secondary metabolites, and cold-associated MAPK signaling pathways. Key enzymes related to 6-gingerol and curcumin biosynthesis were downregulated at 2 °C, suggesting that cold storage may negatively impact ginger quality. Additionally, 2 °C activated the MKK4/5-MPK3/6-related protein kinase pathway, indicating that chilling may increase the risk of ginger pathogenesis.

Research status of ginger insecticidal components in botanical insecticides.

The development and application of botanical insecticides is important for the sustainable development of green agriculture. The abuse of chemical pesticides has caused serious problems of environment and human health. Botanical insecticides have become an environment-friendly insecticides due to their nature, low toxicity, easy degradation and other advantages, which are an important field of insecticide development in the future. Although botanical insecticides have lots of advantages, there are still problems needed to be resolved, such as insecticidal plant species, impact assessment of botanical pesticide and separation and purification of active components. To excavate the resources of highly effective insecticidal plants and understand the mechanism of botanical insecticides, here we reviewed the progress of resources and active components of botanical insecticides, the mechanisms of action of botanical insecticides, the main active components and insecticidal properties of Zingiber officinale. Finally, we analyzed the difficulties faced in the research and development of botanical insecticides, prospected future directions, and discussed the active components of ginger. This review would provide reference for the deve-lopment of new botanical insecticides.

Silica nanoparticles promote wheat growth by mediating hormones and sugar metabolism.

BACKGROUND: Silica nanoparticles (SiNPs) have been demonstrated to have beneficial effects on plant growth and development, especially under biotic and abiotic stresses. However, the mechanisms of SiNPs-mediated plant growth strengthening are still unclear, especially under field condition. In this study, we evaluated the effect of SiNPs on the growth and sugar and hormone metabolisms of wheat in the field. RESULTS: SiNPs increased tillers and elongated internodes by 66.7% and 27.4%, respectively, resulting in a larger biomass. SiNPs can increase the net photosynthetic rate by increasing total chlorophyll contents. We speculated that SiNPs can regulate the growth of leaves and stems, partly by regulating the metabolisms of plant hormones and soluble sugar. Specifically, SiNPs can increase auxin (IAA) and fructose contents, which can promote wheat growth directly or indirectly. Furthermore, SiNPs increased the expression levels of key pathway genes related to soluble sugars (SPS, SUS, and α-glucosidase), chlorophyll (CHLH, CAO, and POR), IAA (TIR1), and abscisic acid (ABA) (PYR/PYL, PP2C, SnRK2, and ABF), whereas the expression levels of genes related to CTKs (IPT) was decreased after SiNPs treatment. CONCLUSIONS: This study shows that SiNPs can promote wheat growth and provides a theoretical foundation for the application of SiNPs in field conditions.

Identification and utilization of a new Bacillus amyloliquefaciens XY-1 against Fusarium head blight.

Fusarium head blight (FHB) is a global wheat grain disease caused by Fusarium graminearum. Biological control of FHB is considered to be an alternative disease management strategy that is environmentally benign, durable, and compatible with other control measures. In this study, to screen antagonistic bacteria with the potential to against FHB, 45 strains were isolated from different tissues of wheat. Among them, seven strains appeared to effectively inhibit F. graminearum growth, the antagonistic bacterium named XY-1 showed a highly antagonistic effect against FHB using dual culture assays. The strain XY-1 was identified as Bacillus amyloliquefaciens by 16S rDNA sequence. Antibiotic tolerance of antagonistic bacteria showed that XY-1 had antagonistic activity against Colletotrichum gloeosporioides, Rhizoctonia solani, Sclerotium rolfsii, and Alternaria alternata. Nutrition tests showed that the most suitable carbon and nitrogen sources were glucose and beef extract, respectively. The optimum growth temperature and pH value were 28 ℃ and 7.4. Antibiotics tolerance cultivation showed that XY-1 had strong resistance to Chloramphenicol and Ampicillin. Wheat spikes inoculation antagonism tests showed that strain XY-1 displayed strong antifungal activity against F. graminearum. Our study laid a theoretical foundation for the application of strain XY-1 as a biological agent in the field to control FHB.

Genome-wide identification of long intergenic non-coding RNAs for Ralstonia solanacearum resistance in tomato (Solanum lycopersicum).

There is growing evidences indicating that long intergenic ncRNAs (lincRNAs) play key roles in plant development and stress responses. To research tomato lincRNA functions during the interaction between tomato and Ralstonia solanacearum, RNA-seq data of tomato plants inoculated with R. solanacearum was analyzed. In this study, 315 possible lincRNAs were identified from RNA-seq data. Then 23 differentially expressed lincRNAs between tomato plants inoculated with R. solanacearum and control were identified and a total of 171 possible target genes for these differentially expressed lincRNAs were predicted. Through GO and KEGG analysis, we found that lincRNA might be involved in jasmonic acid and ethylene signaling pathways to respond to tomato bacterial wilt infection. Furthermore, lincRNA may also be involved in regulating the expression of AGO protein. Subsequently, analysis of expression patterns between differentially expressed lincRNAs and adjacent mRNAs by qRT-PCR revealed that part of lincRNAs and their possible target genes exhibited positive correlation. Taken together, these results suggest that lincRNAs play potential roles in tomato against R. solanacearum infection and will provide fundamental information about the lincRNA-based plant defense mechanisms.

Mining the Roles of Cucumber DUF966 Genes in Fruit Development and Stress Response.

DUF966 genes are widely found in monocotyledons, dicotyledons, mosses, and other species. Current evidence strongly suggests that they are involved in growth regulation and stress tolerance in crops. However, their functions in cucumbers remain unexplored. Here, cucumber CsDUF966 was systemically identified and characterized using bioinformatics. Eight CsDUF966 genes were identified in the cucumber genome. These were phylogenetically separated into three groups. All CsDUF966 proteins were hydrophilic and localized to the nucleus. Moreover, three acidic and five basic proteins were identified. Evolutionary analysis of DUF966 between cucumber and 33 other Cucurbitaceae species/cultivars revealed that most CsDUF966 genes were conserved, whereas CsDUF966_4.c and CsDUF966_7.c were positively selected among the five cucumber cultivars. Expression profiling analysis showed that CsDUF966 had variable expression patterns, and that miRNA164, miRNA166, and Csa-novel-35 were involved in the post-transcriptional regulation of CsDUF966_4.c and CsDUF966_7.c. The expression of CsDUF966_4.c and CsDUF966_7.c, which were under strong neofunctionalization selection, was strictly regulated in fruit and tissues, including seeds, pericarps, peels, and spines, suggesting that these genes are fruit growth regulators and were strongly selected during the cucumber breeding program. In conclusion, the results reveal the roles of CsDUF966s in regulating cucumber fruit development and lay the foundation for further functional studies.

Morphological and Molecular Identification of Fusarium ipomoeae as the Causative Agent of Leaf Spot Disease in Tobacco from China.

Tobacco (Nicotiana tabacum L.), which creates jobs for 33 million people and contributes two trillion dollars' tax annually, is one of the most important economic plants globally. However, tobacco is seriously threatened by numerous diseases during production. Previously, the field survey of tobacco diseases was conducted in the Guizhou and Guangxi provinces, the two main tobacco-producing areas in China. A serious leaf spot disease, with a 22% to 35% incidence, was observed in farming plants. In order to determine the causal agents, we collected the disease samples and isolated the pathogenic fungi. The pathogen was identified as Fusariumipomoeae, based on the morphological characteristics and phylogenetic analysis. Pathogenicity tests showed that F. ipomoeae could induce tobacco leaf spot and blight. To our knowledge, this is the first report worldwide of F. ipomoeae causing leaf spots and stems on tobacco. Our study reveals the serious consequences of F. ipomoeae on tobacco filed production and provides information for future diagnosis and management of the Fusarium disease.

Antibacterial activity and mechanism of ginger extract against Ralstonia solanacearum.

AIMS: The current study aimed to determine the chemical compositions of ginger extract (GE) and to assess the antibacterial activities of GE against the ginger bacterial wilt pathogen Ralstonia solanacearum and to screen their mechanisms of action. METHODS AND RESULTS: A total of 393 compounds were identified by using ultra-performance liquid chromatography and tandem-mass spectrometry. The antibacterial test indicated that GE had strong antibacterial activity against R. solanacearum and that the bactericidal effect exhibited a dose-dependent manner. The minimum inhibitory concentration and minimum bactericidal concentration of R. solanacearum were 3.91 and 125 mg/ml, respectively. The cell membrane permeability and integrity of R. solanacearum were destroyed by GE, resulting in cell content leakage, such as electrolytes, nucleic acids, proteins, extracellular adenosine triphosphate and exopoly saccharides. In addition, the activity of cellular succinate dehydrogenase and alkaline phosphatase of R. solanacearum decreased gradually with an increase in the GE concentration. Scanning electron microscopy analysis revealed that GE treatment changed the morphology of the R. solanacearum cells. Further experiments demonstrated that GE delayed or slowed the occurrence of bacterial wilt on ginger. CONCLUSIONS: GE has a significant antibacterial effect on R. solanacearum, and the antibacterial effect is concentration dependent. The GE treatments changed the morphology, destroyed membrane permeability and integrity, reduced key enzyme activity and inhibit the synthesis of the virulence factor EPS of R. solanacearum. GE significantly controlled the bacterial wilt of ginger during infection. SIGNIFICANCE AND IMPACT OF THE STUDY: This research provides insight into the antimicrobial mechanism of GE against R. solanacearum, which will open a new application field for GE.

Genome-wide characterization and function analysis uncovered roles of wheat LIMs in responding to adverse stresses and TaLIM8-4D function as a susceptible gene.

The Lin-11, Isl-1, and Mec-3 domains (LIM) transcription factors play essential roles in regulating plant biological processes. Despite that, there is a lack of a full understanding of LIMs in wheat (Triticum aestivum L.). In this study, 28 wheat LIM s (TaLIMs) were identified and designated as TaLIM1-1A to TaLIM12-7D. The cis-regulatory element analysis showed that TaLIMs were rich in elements related to biological and abiotic stresses. Expression profiling analysis showed that certain members of TaLIMs were responsive to biotic and abiotic stresses, such as TaLIM1-1A, TaLIM3-2B, TaLIM8-4D, and TaLIM10-5D, were significantly induced by heat, drought, sodium chloride (NaCl), abscisic acid (ABA) and Fusarium graminearum stresses. Furthermore, the biological function of TaLIM8-4D was analyzed and results showed that it was subcellular localization in the nucleus and could induce weak cell death in Nicotiana benthamiana leaves. Additionally, overexpression of TaLIM8-4D could upregulate plant pathogenesis-related (PR) genes, promoting the infection of hemibiotrophic pathogen, implying that TaLIM8-4D could function as susceptible gene in the nucleus by upregulating PR genes and inducing cell death to promote the colonization of hemibiotrophic agent F. graminearum. Overall, the systematic identification, characterization, expression profiling, evolutionary, and function analyses provided the ability to understand TaLIMs and laid a foundation for the further function study of LIM family members in wheat.

Identification of Reference Genes for Reverse Transcription-Quantitative PCR Analysis of Ginger Under Abiotic Stress and for Postharvest Biology Studies.

Gene expression analysis largely improves our understanding of the molecular basis underpinning various plant biological processes. Stable reference genes play a foundational role during the normalization of gene expression levels. However, until now, there have been few reference genes suitable for ginger reverse transcription-quantitative PCR (RT-qPCR) research. In this study, 29 candidate reference genes with stable expression patterns across multiple ginger tissues and 13 commonly used reference genes were selected to design RT-qPCR primers. After amplification specificity validation, 32 candidates were selected and further evaluated by RT-qPCR using samples from various organs subjected to NaCl, drought, heat, waterlogging, and chilling stress. Four strategies, including delta-CT, BestKeeper, geNorm, and NormFinder, were used to rank the stability of reference genes, and the ranks produced by these four strategies were comprehensively evaluated by RefFinder to determine the final rank. Overall, the top three stability reference genes indicated by RefFinder were RBP > ATPase > 40S_S3. Their expression pattern correlation analysis showed that the coefficients among each pair of RBP, ATPase, and 40S_S3 were larger than 0.96, revealing consistent and stable expression patterns under various treatments. Then, the expression of three pathogenesis-related (PR) genes and seven MYB genes in rhizomes during postharvest storage and subjected to pathogen infection was normalized by RBP, ATPase, 40S_S3, RBP and ATPase, ATPase and 40S-S3, and RBP and 40S-S3. The results showed that PR and MYB genes were induced by postharvest deterioration and pathogen infection. The correlation coefficients of RBP/ATPase, RBP/40S_S3, ATPase/40S_S3, RBP and ATPase/ATPase and 40S-S3, RBP and ATPase/RBP and 40S-S3, and ATPase and 40S-S3/RBP and 40S-S3 were 0.99, 0.96, 0.99, 0.99, 1.00, and 1.00, respectively, which confirmed the stability of these three reference genes in postharvest biology studies of ginger. In summary, this study identified appropriate reference genes for RT-qPCR in ginger and facilitated gene expression studies under biotic and abiotic stress conditions.