Fusarium oxysporum f. sp. lycopersici (Fol) causes vascular wilt disease in tomato. Upon colonization of the host, Fol secretes many small effector proteins into the xylem sap to facilitate infection. Besides known SIX (secreted in xylem) proteins, the identity of additional effectors that contribute to Fol pathogenicity remains largely unexplored. We performed a deep RNA-sequencing analysis of Fol race 2-infected tomato, used the sequence data to annotate a published genome assembly generated via PacBio SMRT sequencing of the Fol race 2 reference strain Fol4287, and analysed the resulting transcriptome to identify Fol effector candidates among the newly annotated genes. We examined the Fol-infection expression profiles of all 13 SIX genes present in Fol race 2 and identified 27 new candidate effector genes that were likewise significantly upregulated upon Fol infection. Using Agrobacterium-mediated transformation, we tested the ability of 22 of the new candidate effector genes to suppress or induce cell death in leaves of Nicotiana benthamiana. One effector candidate designated Fol-EC19, encoding a secreted guanyl-specific ribonuclease, was found to trigger cell death and two effector candidates designated Fol-EC14 and Fol-EC20, encoding a glucanase and a secreted trypsin, respectively, were identified that can suppress Bax-mediated cell death. Remarkably, Fol-EC14 and Fol-EC20 were also found to suppress I-2/Avr2- and I/Avr1-mediated cell death. Using the yeast secretion trap screening system, we showed that these three biologically-active effector candidates each contain a functional signal peptide for protein secretion. Our findings provide a basis for further understanding the virulence functions of Fol effectors.

Aims: The association between serum albumin and depressive symptoms has been unclear in previous epidemiological studies. We explored whether serum albumin is associated with depressive symptoms based on the National Health and Nutrition Examination Survey (NHANES) data. Methods: This cross-sectional study included 13,681 participants aged ≥ 20 years from the NHANES performed during 2005–2018, which produced nationally representative database. Depressive symptoms were assessed using the Patient Health Questionnaire-9. Serum albumin concentration was measured using the bromocresol purple dye method, and participants were divided into quartiles of serum albumin concentrations. Weighted data were calculated according to analytical guidelines. Logistics regression and linear regression models were used to assess and quantify the association between serum albumin and depressive symptoms. Univariate and stratified analyses were also performed. Results: There were 1551 (10.23%) adults (aged ≥ 20 years) with depressive symptoms among the 13,681. A negative association was found between serum albumin concentration and depressive symptoms. Compared with the lowest albumin quartile, the multivariate-adjusted effect size (95% confidence interval) for depressive symptoms of the fully adjusted model in the highest albumin quartile was 0.77 (0.60 to 0.99) and − 0.38 (− 0.66 to − 0.09) using logistics regression and linear regression models respectively. Current smoking status modified the association between serum albumin concentration and PHQ-9 scores (p for interaction = 0.033). Conclusion: This cross-sectional study revealed that albumin concentration is significantly more likely to be a protective factor for depressive symptoms, with the association being more pronounced in non-smokers.

Prevention of autonomous division of the egg apparatus and central cell in a female gametophyte before fertilization ensures successful reproduction in flowering plants. Here we show that rice ovules of Polycomb repressive complex 2 (PRC2) Osfie1 and Osfie2 double mutants exhibit asexual embryo and autonomous endosperm formation at a high frequency, while ovules of single Osfie2 mutants display asexual pre-embryo-like structures at a lower frequency without fertilization. Earlier onset, higher penetrance and better development of asexual embryos in the double mutants compared with those in Osfie2 suggest that the autonomous endosperm facilitated asexual embryo development. Transcriptomic analysis showed that male genome-expressed OsBBM1 and OsWOX8/9 were activated in the asexual embryos. Similarly, the maternal alleles of the paternally expressed imprinted genes were activated in the autonomous endosperm, suggesting that the egg apparatus and central cell convergently adopt PRC2 to maintain the non-dividing state before fertilization, possibly through silencing of the maternal alleles of male genome-expressed genes.

Tea-oil Camellia species as edible-oil producing trees are widely cultivated in southern China. Camellia anthracnose that is mainly caused by Colletotrichum fructicola is a major disease of tea-oil trees. However, rapid detection and precise quantification of C. fructicola in different Camellia species that are crucial for the fundamental study of this pathosystem and effective disease management remain largely unexplored. Here, we developed a sensitive, rapid, and accurate method for quantifying C. fructicola growth in different Camellia species using a quantitative PCR assay. Amplified C. fructicola DNA using ITS-specific primers is relatively compared with the amplification of Camellia oleifera using the TUB gene. We determined that the fungal growth is tightly associated with the disease development in Ca. oleifera following C. fructicola infection in a time-course manner. This assay is highly sensitive, as fungal growth was detected in six different inoculated tea-oil Camellia species without visible disease lesion symptoms. Additionally, this method was validated by quantifying the Camellia anthracnose in orchards that did not show any disease symptoms. This assay enables the rapid, highly sensitive, and precise detection and quantification of C. fructicola growth in different tea-oil Camellia species, which will have a practical application for early diagnosis of anthracnose disease under asymptomatic conditions in Camellia breeding and field and will facilitate the development of tea-oil trees and C. fructicola interaction as a mold system to study woody plant and fungal pathogens interaction.

The function of callose and its deposition characteristics at phloem in the resistance to the long-distance transportation of Soybean mosaic virus (SMV) through phloem was studied. Two different methods of SMV inoculation were used in the study, one was direct friction of the virus on seedling leaves and the other was based on grafting scion and rootstock to create different resistance and sensitivity combinations. Veins, petioles of inoculated leaves and rootstock stems were stained with callose specific dye. Results from fluorescence microscope observation, pharmacological test, and PCR detection of SMV coat protein gene (SMV-CP) showed the role of callose in long-distance transportation of SMV through phloem during infection of soybean seedlings. When the inhibitor of callose synthesis 2-deoxy-D-glucose (2-DDG) was used, the accumulation of callose fluorescence could hardly be detected in the resistant rootstocks. These results indicate that callose deposition in phloem restricts the long-distance transport of SMV, and that the accumulation of callose in phloem is a main contributing factor for resistance to this virus in soybean.

Fusarium oxysporum f. sp. lycopersici (Fol) causes vascular wilt disease in tomato. Upon colonization of the host, Fol secretes many small effector proteins into the xylem sap to facilitate infection. Besides known SIX (Secreted In Xylem) proteins, the identity of additional effectors that contribute to Fol pathogenicity remains largely unexplored. We have performed a deep RNA-sequencing analysis of Fol race 2-infected tomato, used the sequence data to annotate a published genome assembly generated via PacBio SMRT sequencing of the Fol race 2 reference strain Fol4287, and analysed the resulting transcriptome to identify Fol effector candidates among the newly annotated genes. We examined the Fol-infection expression profiles of all 13 SIX genes present in Fol race 2 and identified 27 new candidate effector genes that were likewise significantly upregulated upon Fol infection. Using Agrobacterium-mediated transformation, we tested the ability of 22 of the new candidate effector genes to suppress or induce cell death in leaves of Nicotiana benthamiana. One effector candidate designated Fol-EC19, encoding a secreted guanyl-specific ribonuclease, was found to trigger cell death and two effector candidates designated Fol-EC14 and Fol-EC20, encoding a glucanase and a secreted trypsin, respectively, were identified that can suppress Bax-mediated cell death. Remarkably, Fol-EC14 and Fol-EC20 were also found to suppress I-2/Avr2- and I/Avr1-mediated cell death. Using the yeast secretion-trap screening system, we showed that these three biologically-active effector candidates each contain a functional signal peptide for protein secretion. Our findings provide a basis for further understanding the virulence functions of Fol effectors.