Overexpressing CsSABP2 enhances tolerance to Huanglongbing and citrus canker in C. sinensis

Huanglongbing (HLB) and citrus canker, arising from Candidatus Liberibacter asiaticus (CaLas) and Xanthomonas citri pv. Citri (Xcc), respectively, have been imposing tremendous losses to the global citrus industry. Systemic acquired resistance (SAR) has been shown to be crucial for priming defense against pathogen in citrus. Salicylic acid (SA) binding protein 2 (SABP2), which is responsible for converting methyl salicylate (MeSA) to SA, is essential for full SAR establishment. Here, we characterized the functions of four citrus SABP2 genes (CsSABP2-1, CsSABP2-1V18A, CsSABP2-2 and CsSABP2-3) against HLB and citrus canker. In vitro enzymatic assay revealed that all four proteins had MeSA esterase activities, and CsSABP2-1 and CsSABP2-1V18A has the strongest activity. Their activities were inhibited by SA except for CsSABP2-1V18A. Four genes controlled by a strong promoter 35S were induced into Wanjincheng orange (Citrus sinensis Osbeck) to generate transgenic plants overexpressing CsSABP2. Overexpressing CsSABP2 increased SA and MeSA content and CsSABP2-1V18A had the strongest action on SA. Resistance evaluation demonstrated that only CsSABP2-1V18A had significantly enhanced tolerance to HLB, although all four CsSABP2s had increased tolerance to citrus canker. The data suggested the amino acid Val-18 in the active site of CsSABP2 plays a key role in protein function. Our study emphasized that balancing the levels of SA and MeSA is crucial for regulating SAR and conferring broad-spectrum resistance to HLB and citrus canker. This finding offers valuable insights for enhancing resistance through SAR engineering

The combined association of adherence to recommended physical activity and glycemic control with depression: an exploratory study with mediation and moderation models

Abstract Background Both physical activity and dysglycemia are associated with depression. However, the combined association of adherence to recommended physical activity (RPA) and glycemic control with depression is unknown. Moreover, the extent to which glycemic control mediates the association between physical activity and depression is not established. Methods The sample included 31,302 adults from the National Health and Nutrition Examination Survey 2007-08 to 2017-18. Adherence to RPA for aerobic activity was defined according to the WHO 2020 guidelines. HbA1c was classified as < 5.7%, 5.7–6.4%, 6.5–6.9%, and ≥ 7.0%. Depression was evaluated according to the 9-item Patient Health Questionnaire. The odds ratio for depression stratified by adherence to RPA and HbA1c level were estimated by logistic regressions. Mediation analysis was performed to estimate the direct associations (not through glycemic control) and indirect associations (through glycemic control). Results A total of 2871 participants were diagnosed with depression. Compared to participants with HbA1c level < 5.7% who adhere to RPA, those with HbA1c level < 5.7%, 5.7-6.4%, 6.5-6.9%, and ≥ 7.0% who did not adhere to RPA had increased odds ratio for depression, especially in women and older adults. Individuals with HbA1c ≥ 7.0% still had an increased odds ratio for depression even though they were physically active. The results of the mediation analysis were insignificant. Conclusion There was a combined association of adherence to RPA and glycemic control with depression in women and older adults. We did not find out evidence of glycemic control mediation on the pathway from physical activity to depression

Contribution of Ambient Light Intensity vs Spectral Contents of Short Wavelength on Refractive Development in Young Rabbits

Abstract Background:The aim of this study was to compare the effects of manipulating lighting levels versus manipulating the short wavelength contents of ambient lighting on refractive development in young rabbits. Methods: A total of 32 healthy 3-week-old rabbits were randomly assigned to one of four groups with 8 in each group. Normal blue at normal illuminance (control, NC) group and normal blue at high illuminance lighting (HI) group were exposed to light emitted by ordinary LED lamps with low content in the short wavelength range. High-blue at high illuminance(Simulating natural light, S-NL) group and high-blue at normal illuminance (High-blue, HB) group were exposed to the light with high content in the short wavelength range provided by ordinary LED and blue LED lamps. The approximate mean illuminance (in human lux) on the cage floor was (NC:341lux, HI:5057lux, HB:342lux, S-NL: 5051lux). Refractive error, axial dimensions and corneal curvature radius were assessed by retinoscopy, ultrasonography and keratometry, respectively. Average data of both eyes for each animal were compared across groups.Results: During the intervention, all animals had an emmetropization period. The refractive development of HI group was similar to S-NL group, both significantly slower than that of HB and NC group (p&lt;0.001). While the decrease of group refraction in HB paralleled to the control group (p=0. 381). At the 12th week, the group refraction of S-NL(3.000±0.267D) was similar to HI (3.250±0.267D), more hyperopic than HB(2.219±0.281D) and NC (1.938±0.291D). The vitreous chamber depth of S-NL (7.421±0.168mm) was shorter than HB (7.785±0.230mm) and NC (7.825±0.313mm), similar to that of HI group(7.264±0.256mm). The other components were less effected by light conditions(p＞0.05). Conclusions: Extrapolated from rabbits, these findings suggest that high illuminances per se but not the rich in short wavelengths determine the inhibitory effect of ambient lighting on myopia after increasing time outdoors.</jats:p

A 100 bp GAGA motif-containing sequence in AGAMOUS second intron is able to suppress the activity of CaMV35S enhancer in vegetative tissues.

Flower-specific promoters enable genetic manipulation of floral organs to improve crop yield and quality without affecting vegetative growth. However, the identification of strong tissue-specific promoters is a challenge. In addition, information on cis elements that is able to repress gene expression in vegetative tissues remains limited. Here, we report that fusing a 35S enhancer to the stamen- and carpel-specific NtAGIP1 promoter derived from the tobacco AGAMOUS second intron (AGI) can significantly increase the promoter activity. Interestingly, although the activity of the new promoter extends to sepals and pedicles, it does not cross the boundary of the reproductive organs. Serial deletion of the AGI and chromatin immunoprecipitation (ChIP) assay reveal a 100-bp fragment that contains a conserved GAGA factor binding motif contributes to the flower specificity by mediating histone H3 lysine 27 trimethylation (H3K27me3) modification of the promoter. Furthermore, this fragment shows significant suppressive effect on the activity of the 35S enhancer in vegetative tissues, consequently, resulting in a significant increase of the activity of 35S enhancer:AGI chimeric promoter without sacrifice of its specificity in inflorescence