Latest ArticlesCarbonic anhydrase (CA) plays an important role in the photosynthesis of plants and response to stress. Cassava CA gene was cloned using the cDNA of SC124 as template. The CDS length of MeCA was 1008 nt, encoding 336 amino acids. The homology was 99.70% between the cloned sequence and Manes.15G167500.1 in the database. The evolutionary tree resulted that MeCA belonged to the same branch as the AtβCA subfamily of Arabidopsis. The sequence similarity between MeCA and AtβCA1 protein reached 73.13% and contained identical motif. MeCA gene expression was the highest in functional leaves, followed in young leaves, significantly higher in fibrous roots and stems, and significantly down-regulated in shading stressed cassava leaves. In addition, the gene showed significant upregulated expression in the initial stage, and then it dropped to the control level when cassava leaves were treated with low temperature. This study created transgenic cassava with overexpression of MeCA gene, and observed that MeCA protein was localized in chloroplasts, and the contents of various chlorophyll were significantly higher in the leaves of transgenic plants than that of control. The results of yeast two-hybrid point-to-point experiments showed that MeCA protein interacted with MeH1.2. The result indicated that MeCA gene could respond to light and low temperature stresses, and maight participate in plant response to stress by affecting plant growth interacting with MeH1.2 proteins. This study would provide a new gene resource for genetic improvement of cassava resistance.
Tea tree oil (TTO) chitosan emulsion was prepared by ultra-high pressure homogenization method with natural TTO and chitosan as raw materials, Tween-80 as emulsifying agent, and ethanol as co-emulsifying agent. The preparation conditions were optimized by response surface test. The storage stability of TTO chitosan emulsion at different temperatures was investigated, and its antioxidant activity and mildew proof properties were evaluated. The optimal preparation conditions of the emulsion were as follows, the homogenization pressure 160 MPa, the mass fraction of tea tree oil 12%, and the mass fraction of compound emulsifier 4%. Under the conditions, the particle size of the emulsion was 99.24 nm. When stored at 4, 25 and 50 ℃ for 28 days, the particle size remained within 164 nm, the Zeta potential all exceeded 39 mV, and the PDI remained within 0.53, indicating that the storage stability of the emulsion was good. The IC50 value of DPPH radical and OH radical of the emulsion was 22.82 μL/mL and 18.75 μL/mL, respectively, indicating that the emulsion had good antioxidant activity. The mildew proof test showed that the mildew proof ability of bamboo treated with TTO chitosan emulsion was higher than that of untreated bamboo. When the treatment concentration was 80 μL/mL, the antifungal effect was significant.
Annona squamosa L., a vital tropical fruit crop in southern China, faces escalating threats from fungal diseases, though rust pathogens had not been previously documented domestically. This study reported the first dectection of Phakopsora cherimoliae, a high-risk rust fungus known to cause severe yield losses (>30%) in Central and South America, detected in Yunxiao county, Fujian province. Field symptoms included chlorotic flecks on adaxial leaf surfaces progressing to reddish-brown necrotic lesions with abaxial yellowish-brown uredinia. Morphometric analysis revealed ellipsoid to ovoid urediniospores, long axis is (28.0±2.5)μm; short axis is (22.7±3.2)μm, consistent with P. cherimoliae descriptions but notably smaller than those reported on A. cherimola hosts, suggesting potential host-driven morphological adaptation. Molecular characterization via LSU rDNA sequencing indicated that the sequence of the three isolates obtained in this study exhibited over 99% identity with the reference strain KF528012. Phylogenetic analysis using maximum likelihood and the Kimura-2 parameter method positioned the isolates in a distinct monophyletic clade with 100% bootstrap support, separate from other related Phakopsora species. Pathogenicity was confirmed through Koch's postulates. Inoculation of healthy Annona trees with filed urediniospores induced identical symptoms and new urediniospores within 14 days. The absence of telia indicated dependence on urediniospores for asexual propagation, raising concerns about persistent epidemics under Fujian's humid subtropical climate, where monsoon winds may facilitate regional dispersal. Urgent management strategies include pre-monsoon application of tebuconazole, systematic removal of infected debris, and resistance screening across commercial cultivars (e.g., ‘African Pride’). Study limitations include unresolved telial stage biology and unquantified spore dispersal dynamics, warranting long-term phenological monitoring and aerobiological modeling. This invasion event underscores vulnerabilities in China's tropical fruit biosecurity, emphasizing the imperative for enhanced phytosanitary surveillance and international collaboration to mitigate cross-border pathogen spread. The findings establish a critical baseline for rust disease management in Asian Annona production systems, bridging a longstanding gap in regional plant pathology literature.
The AT-hook Motif Nuclear Localized (AHL) protein family is known for its pivotal roles in plant growth regulation, developmental patterning, and stress signal transduction. Although the gene family has been studied in various plant species, the genomic characteristics, evolutionary mechanism, and expression profiles of the AHL family in cassava (Manihot esculenta) remain unexplored. In this study, we comprehensively investigated the evolutionary features and biological response of the MeAHL gene family through genome-wide identification, phylogenetic analysis, structural characterization, and large-scale transcriptomes based on the cassava SC205 reference genome. We identified 41 putative members through genome-wide identification. Physicochemical property analysis showed that all 41 MeAHLs were hydrophilic proteins, and 40 of them were unstable proteins, with the number of amino acids generally ranging from 188 to 446 aa. Phylogenetic analysis indicated that the MeAHL family members could be divided into two clades, Clade A and Clade B. Two MeAHL gene clusters were located in the distal telomeric regions of chromosomes Chr01 and Chr02, respectively. Replication type analysis revealed that the evolution of MeAHLs was mainly driven by whole-genome duplication (WGD) and dispersed duplication (DSD), with the Ka/Ks values <1. Evolutionary mechanism analysis indicated that whole-genome duplication (WGD) primarily drove the MeAHL gene family expansion. Gene structure analysis showed that MeAHL genes were mainly composed of 1‒10 exons. Analysis of conserved domains and motifs showed that all MeAHLs had the PPC/DUF296 domain and AT-hook motif. Members of Clade A generally contained one Type-I AT-hook motif. Among members of Clade B, except for SC20508G13380 and SC20509G13950, which contained one Type-II AT-hook motif, most members contained two AT-hooks (Type-I and Type-II). Cis-acting element analysis via PlantCARE showed that the cis-acting elements related to light response were the most abundant in MeAHLs, such as Box 4, G-box, and they also contained elements responsive to hormones, biotic stresses, and abiotic stresses, such as ABRE, MBS, W-box, and TC-rich repeats. Tissue-specific expression profiling revealed distinct expression patterns between two clades of MeAHL across 11 different tissues. Stress transcriptome analysis demonstrated significant responses of specific MeAHLs to drought (ABA/PEG treatments), cassava bacterial blight (Xanthomonas axonopodis pv. manihotis), and mite infestation, showing clade-specific regulatory patterns. Protein-protein interaction (PPI) network prediction suggested some MeAHLs formed functional modules with bHLH, NAC, ARF, and NB-LRR proteins involved in plant development and stress responses. This study would provide the systematic characterization of AHL family evolution and functional diversification in cassava, offering theoretical foundations for molecular breeding applications.
40 newly developed domestic sugarcane varieties (lines) were used to screen sugarcane varieties with strong cold tolerance and excellent comprehensive traits in Quanzhou county, Guangxi. The results indicated that the value of plant height, stem diameter, millable stalk number, single stalk weight and cane yield of plant crop were higher than those in ratoon crop under natural low temperature conditions, with extremely significant difference observed in plant height, single stalk weight, and cane yield between plant crop and ratoon crop. There were significant or highly significant difference in plant height, stem diameter, millable stalk number, single stalk weight and cane yield among different varieties. Field brix, sucrose content and purity of plant crop and ratoon crop exhibited an ascending trend before the arrival of the first strong low-temperature weather, afterwards exhibited an declining trend. Stalk length damage rate (SDR) demonstrated a progressive increase across three survey periods in both plant crop and ratoon crop, but green leaves percentage (GLP) was gradually decreasing. Plant damage rate (PDR) differed among varieties initially, while in the second and third investigation, PDR reached 100% for all varieties. GT51, GT32, GT13-532, DZ09-78, GT58 and GT52 exhibited strong cold tolerance based on the the subordinate function method. The result from maximum entropy-minimum residual composite index model demonstrated that sugar content, cane yield and millble cane number in ratoon crop ranked the top three in weight coefficients, exerting significant impacts on the comprehensive evaluation of sugarcane varieties. DZ07-36, ZT1, ZZ6, YT07-913, FN38, DZ09-78, GT55, GT51, GT52, GT42 and GT58 showed overall superior performance and are suitable for promotion in colder northern sugarcane-growing regions.
During the biosynthesis process of lignin in plants, cinnamyl alcohol dehydrogenase (CAD) plays a crucial role, catalyzing the final step reaction in the entire metabolic pathway. To explore the potential functions of the CAD gene family in tea plants, CAD gene family members were identified in the genome of Huangyan tea plants and a series of bioinformatics analyses were conducted. Based on transcriptome data, the gene expression of the members in different organs of tea plants and after damage by the Empoasca vitis were studied. A total of 36 members of HD-CsCADs were identified, which were unevenly distributed on 9 chromosomes and encoded amino acid lengths ranging from 300 aa to 621 aa and protein molecular weights ranging from 321.40 kDa to 666.49 kDa. HD-CsCADs had 0 to 3 introns and the promoters containing 79 types of cis-acting elements, among which the number of elements related to stress response was the highest. Combined with the phylogenetic tree, HD-CsCADs could be divided into 4 subfamilies. There were significant differences in the expression levels of HD-CsCADs in different organs of tea plants. HD-CsCAD-15 was highly homologous to CAD genes involved in lignin biosynthesis in other plants and was highly expressed in stem tissues. In addition, the expression of the genes after damage by E. vitis on tea seedlings was analyzed. The expression of HD-CsCAD-11 and HD-CsCAD-15 was relatively obvious and could be used as important CAD genes related to lignin metabolism and tea plant defense against pests. The results would provide theoretical basis for the defense mechanism of tea plants against the small green leaf hopper and the utilization of CAD gene functions.
The 3rd to 5th instar nymphs and adults were released in tobacco fields and greenhouses to investigate the differences in dispersal capacity and dynamic patterns across developmental stages of Eocanthecona furcellata (Wolff). Under greenhouse conditions, dispersal characteristics including release timing, spatial distribution, diffusion coefficients and colonization rates were analyzed. Additionally, dispersal velocities across different developmental stages were measured under field conditions. Results demonstrated variations in dispersal capacity among developmental stages within 12-48 hours post-release, showing a gradual enhancement trend with advancing insect age. Throughout the release period, adults exhibited significantly higher dispersal coefficients than nymphs in tobacco fields, while in greenhouses, adult dispersal coefficients only surpassed nymphs significantly during 12-24 hours post-release. During dispersal, nymphs in the greenhouse primarily clustered on tobacco plants, while the majority of adults exhibited a radial dispersal tendency. At 72 hours post-release, significant differences in colonization rates emerged among developmental stages in greenhouses, with adults achieving markedly higher rates than nymphs, demonstrating a stepwise decline as instar levels decreased (adult>5th>4th>3rd). Dispersal patterns stabilized with prolonged release duration. This study would provide critical evidence for scientifically evaluating the biocontrol potential of E. furcellata, offering substantial significance for enhancing natural enemy efficacy and advancing scientific pest management strategies.
Cucumber mosaic virus (CMV) is a virus that can infect various monocotyledonous and dicotyledonous plants. Two efficient detection methods for CMV in orchids, real-time quantitative PCR (RT-qPCR) and reverse transcription loop-mediated isothermal amplification (RT-LAMP) were developed in the study. For RT-qPCR, a TaqMan probe-based assay was designed using conserved regions of the coat protein (cp) gene, with a cloned cp plasmid serving as the standard for calibration curve construction. For RT-LAMP, specific inner and outer primers were designed based on the cp gene conserved sequences too. Both methods specificity detection were performed using virus RNA from CMV, Cymbidium mosaic virus (CymMV), and Odontoglossum ringspot virus (ORSV) as templates, and for sensitivity detection was performed using 10-fold serial dilutions of CMV RNA as a template. Additionally, field-collected orchid samples were screened for CMV infection using both techniques. The CMV RT-qPCR and RT-LAMP detection methods established in this study detected only CMV-positive samples without cross-reactivity with CymMV or ORSV. The sensitivity of RT qPCR and RT LAMP was consistent with a dilution of 106 times the original solution. The positive rate of CMV in field orchid samples was 26.7%. The results demonstrate that the RT-qPCR and RT-LAMP established in this study have strong specificity and high sensitivity, and are suitable for monitoring CMV infection in orchids in actual production processes.
The study established an ultra-performance liquid chromatography-tandem mass spectrometry technique for the simultaneous determination of six methoxyacrylate fungicides to clarify the possible cumulative dietary intake risk of methoxyacrylate fungicides in fresh mango. The Monte Carlo simulation and relative potency factor methods were employed to assess the cumulative risk of acute and chronic exposure to strobilurin intake from mango consumption in the targeted populations. In 126 mango samples from Hainan, Guangxi and Yunnan, 3 of 6 methoxyacrylate fungicide were detected. The detection rate of pyraclostrobin, azoxystrobinthe and kresoxim-methyl was 31%, 37% and 14% respectively. Picoxystrobin, trifloxystrobin and fluoxastrobin in mango samples were not detected. The ratio of methoxyacrylate fungicide found in a mango sample was 22%. The ratio of 2 and 3 kinds methoxyacrylate fungicides found in a mango sample was 22% and 5%. The most common co-occurrence of methoxyacrylate fungicides was pyraclostrobin and azoxystrobin. The results of dietary risk assessment showed that the risk of residual methoxyacrylate fungicides in mango ranged between 0.1% and 10.2% for acute dietary exposure and between 0.1% and 1.2% for chronic dietary exposure. The exposure was far below the thresholds of dietary risk. The study showed that the cumulative chronic and acute dietary exposure risk of methoxyacrylate fungicide residues in mango are within an acceptable range and do not pose an unacceptable risk to the health of the targeted population.
Improving and upgrading the efficiency of sugar factories and income of sugarcane farmers are the fundamental goals of the sugarcane industrial development. This study introduced the breeding process of the early-maturing, high-sugar, high-yield, automatic defoliation new sugarcane variety Guitang 76 (GT76) and its production efficiency in different regions, in order to provide planting technical basis for this new sugarcane variety in the coming years. Guitang 76 was selected through the “five nurseries” breeding procedure, and developed based on traits of early maturity, high sugar content and high yield, and also included characteristics of strong perennial roots, high uniformity, tolerance to drought, disease and infertility, and automatic defoliation. Finally, the Guitang 76 production performance was evaluated through the Guangxi new sugarcane variety regional test. The main process was as follows: In April 2010, 220 seedlings were obtained from the combination of CP81-1254×ROC22, planted in the hybrid nursery. In February 2011, five healthy individual plants were selected from the hybrid nursery and planted in the selection nursery. In December 2011, two strains were selected from the selection nursery and entered the identification nursery. In January 2013, one strain was selected from the identification nursery (named Guitang 10-2118), and in February 2013, it entered the preparation variety comparison nursery. After observation and screening, it was selected into the variety comparison nursery in March 2014, and later selected for the 2021—2023 of Guangxi sugarcane new variety regional trials (one year new planted sugarcane and two years perennial sugarcane trials). The results of regional trials showed that the stem diameter of Guitang 10-2118 was between 2.5–3.0 cm, which is a medium-large stem variety, the average number of effective stems was 8140 per hm2 more than that of the control variety ROC22. The yield of newly planted sugarcane was 7.72% lower than that of ROC22, but the yield of perennial sugarcane in the first year was 7.28% higher than that of ROC22, and the yield of perennial sugarcane in the second year was 15.24% higher than that of ROC22, and the average yield in three years was higher (5.24%) than that of ROC22. The average sucrose content from November to March was 15.04%, which was 1.32% higher than that of ROC22. Guitang 10-2118 also showed other significant traits including tall plants, long internodes, automatic defoliation, strong perennial roots, wide adaptability, high resistance to smut and tip rot, etc. Guitang 10-2118 was renamed as Guitang 76 (GT76). This article also introduced the key points of cultivation strategies of GT76, providing technical support for its promotion, application and better cane production in coming years.