Dynamic characteristics and functional analysis provide new insights into the role of GauERF105 for resistance against Verticillium dahliae in cotton.

BACKGROUND: The cotton industry suffers significant yield losses annually due to Verticillium wilt, which is considered the most destructive disease affecting the crop. However, the precise mechanisms behind this disease in cotton remain largely unexplored. METHODS: Our approach involved utilizing transcriptome data from G. australe which was exposed to Verticillium dahliae infection. From this data, we identified ethylene-responsive factors and further investigated their potential role in resistance through functional validations via Virus-induced gene silencing (VIGS) in cotton and overexpression in Arabidopsis. RESULTS: A total of 23 ethylene response factors (ERFs) were identified and their expression was analyzed at different time intervals (24 h, 48 h, and 72 h post-inoculation). Among them, GauERF105 was selected based on qRT-PCR expression analysis for further investigation. To demonstrate the significance of GauERF105, VIGS was utilized, revealing that suppressing GauERF105 leads to more severe infections in cotton plants compared to the wild-type. Additionally, the silenced plants exhibited reduced lignin deposition in the stems compared to the WT plants, indicating that the silencing of GauERF105 also impacts lignin content. The overexpression of GauERF105 in Arabidopsis confirmed its pivotal role in conferring resistance against Verticillium dahliae infection. Our results suggest that WT possesses higher levels of the oxidative stress markers MDA and H2O2 as compared to the overexpressed lines. In contrast, the activities of the antioxidant enzymes SOD and POD were higher in the overexpressed lines compared to the WT. Furthermore, DAB and trypan staining of the overexpressed lines suggested a greater impact of the disease in the wild-type compared to the transgenic lines. CONCLUSIONS: Our findings provide confirmation that GauERF105 is a crucial candidate in the defense mechanism of cotton against Verticillium dahliae invasion, and plays a pivotal role in this process. These results have the potential to facilitate the development of germplasm resistance in cotton.

Histochemical Analyses Reveal That Stronger Intrinsic Defenses in Gossypium barbadense Than in G. hirsutum Are Associated With Resistance to Verticillium dahliae.

Verticillium wilt, caused by Verticillium dahliae Kleb., is a serious threat to cotton (Gossypium spp.) crop production. To enhance our understanding of the plant's complex defensive mechanism, we examined colonization patterns and interactions between V. dahliae and two cotton species, the resistant G. barbadense and the susceptible G. hirsutum. Microscopic examinations and grafting experiments showed that the progression of infection was restricted within G. barbadense. At all pre- and postinoculation sampling times, levels of salicylic acid (SA) were also higher in that species than in G. hirsutum. Comparative RNA-Seq analyses indicated that infection induced dramatic changes in the expression of thousands of genes in G. hirsutum, whereas those changes were fewer and weaker in G. barbadense. Investigations of the morphological and biochemical nature of cell-wall barriers demonstrated that depositions of lignin, phenolic compounds, and callose were significantly higher in G. barbadense. To determine the contribution of a known resistance gene to these processes, we silenced GbEDS1 and found that the transformed plants had decreased SA production, which led to the upregulation of PLASMODESMATA-LOCATED PROTEIN (PDLP) 1 and PDLP6. This was followed by a decline in callose deposition in the plasmodesmata, which then led to increased pathogen susceptibility. This comparison between resistant and susceptible species indicated that both physical and chemical mechanisms play important roles in the defenses of cotton against V. dahliae.

Biomechanical Analysis of Cortical Bone Trajectory Screw Versus Bone Cement Screw for Fixation in Porcine Spinal Low Bone Mass Model.

STUDY DESIGN: A prospective study of in vitro animal. OBJECTION: To compare the biomechanics of cortical bone trajectory screw (CBT) and bone cement screw (BC) in an isolated porcine spinal low bone mass model. SUMMARY OF BACKGROUND DATA: The choice of spinal fixation in patients with osteoporosis remains controversial. Is CBT better than BC? Research on this issue is lacking. METHODS: Ten porcine spines with 3 segments were treated with EDTA decalcification. After 8 weeks, all the models met the criteria of low bone mass. Ten specimens were randomly divided into groups, group was implanted with CBT screw (CBT group) and the other group was implanted with bone cement screw (BC group). The biomechanical material testing machine was used to compare the porcine spine activities of the two groups in flexion, extension, bending, and axial rotation, and then insertional torque, pull-out force, and anti-compression force of the 2 groups were compared. Independent sample t test was used for comparison between groups. RESULTS: Ten 3 segments of porcine spine models with low bone mass were established, and the bone mineral density of all models was lower than 0.75 g/cm 2 . There is no difference between the CBT and BC groups in flexion, extension, bending, and axial rotation angle, P >0.05. However, there were significant differences between the 2 groups and the control group, with P ＜0.01. The 2 groups significantly differed between the insertional torque ( P =0.03) and the screw pull-out force ( P =0.021). The anti-compression forces between the 2 groups have no significant difference between the two groups ( P =0.946). CONCLUSIONS: The insertional torque and pull-out force of the CBT were higher than those of the BC in the isolated low bone porcine spine model. The range of motion and anti-compression ability of the model was similar between the 2 fixation methods.

The Correlation Between the Diffusion Coefficient of Bone Cement and Efficacy in Percutaneous Vertebroplasty.

This study investigated the effect of bone mineral density (BMD) on the diffusion coefficient (DC) of bone cement in percutaneous vertebroplasty (PVP) and the correlation between the DC and the efficacy after PVP. This was a retrospective study of PVP cases with follow-up longer than 12 months. The cases were assigned to 3 groups according to the BMD: BMD decrease group, osteoporosis group, and severe osteoporosis group. The 3 groups were compared regarding bone cement injection volume (IV), diffusion volume (DV), DC, visual analog scale (VAS) score, Oswestry Disability Index (ODI) score, and vertebral height loss ratio (VHLR). The correlation between DC and BMD, IV, DV, and VHLR was analyzed. The least significant difference test was used for comparison among the 3 groups, and the Pearson correlation coefficient was used for correlation analysis. There were a total of 132 cases, including 34 males and 98 females with a mean age of 76.5±9.6 years. The DV was larger than the IV in each group (P<.05). There was no statistically significant difference in the IV, VAS score, and ODI among the 3 groups (P>.05). However, there were significant differences in the DC and VHLR among the 3 groups (P<.05). Correlation analysis showed that there were significant correlations between BMD and IV (-0.716), BMD and DC (0.754), IV and DV (0.502), and IV and DC (-0.666) (P<.01). Scatter plot showed that the correlation between IV and BMD was r=0.716, R2=0.513, and the correlation between DC and BMD was r=0.754, R2=0.568. The DV was larger than the IV in PVP, and BMD was closely related to the DC. The higher the BMD, the higher the DC. Short-term follow-up revealed that the DC was inversely proportional to the VHLR. [Orthopedics. 2021;44(1):e95-e100.].