Etiological diagnostic performance of probe capture-based targeted next-generation sequencing in bloodstream infection.

Background: A rapid and precise etiological diagnosis is crucial for the effective treatment of bloodstream infection (BSI). In this study, the performance of probe capture-based targeted next-generation sequencing (tNGS) was compared to that of blood culture and metagenomic next-generation sequencing (mNGS) in detecting potential pathogens in patients with BSI. Methods: A total of 80 patients with suspected BSI were prospectively enrolled from 24 November 2023 to 30 December 2023 at Zhongshan Hospital, Shanghai, China. All 80 participants underwent simultaneous blood culture, blood mNGS, and blood tNGS after admission when febrile, and the results were compared. Results: Among the 80 participants, 11 were clinically diagnosed with noninfectious fever, and 69 were diagnosed with BSI. Blood tNGS had a higher sensitivity for the diagnosis of BSI than blood culture (91.3% vs. 23.2%, P<0.001) and blood mNGS (91.3% vs. 69.6%, P=0.001). There was no significant difference in specificity between blood mNGS and tNGS (81.8% vs. 100.0%, P=0.13). Blood tNGS demonstrated a faster turnaround time than blood culture and blood mNGS. In 22 (31.9%) patients with BSI, targeted adjustment of the anti-infectious therapy according to the blood tNGS results resulted in clinical improvement. Conclusions: Blood tNGS may be a promising tool for detecting potential pathogens in patients with BSI. The application of blood tNGS for BSI could guide anti-infectious treatment strategies and might improve clinical outcomes.

OsTCP19 coordinates inhibition of lignin biosynthesis and promotion of cellulose biosynthesis to modify lodging resistance in rice.

Lignin and cellulose are two essential elements of plant secondary cell walls that shape the mechanical characteristics of the culm to prevent lodging. However, how the regulation of the lignin and cellulose composition is combined to achieve optimal mechanical characteristics is unclear. Here, we show that increasing OsTCP19 expression in rice coordinately repressed lignin biosynthesis and promoted cellulose biosynthesis, resulting in enhanced lodging resistance. In contrast, repression of OsTCP19 coordinately promoted lignin biosynthesis and inhibited cellulose biosynthesis, leading to greater susceptibility to lodging. We found that OsTCP19 binds to the promoters of both MYB108 and MYB103L to increase their expression, with the former being responsible for repressing lignin biosynthesis and the latter for promoting cellulose biosynthesis. Moreover, up-regulation of OsTCP19 in fibers improved grain yield and lodging resistance. Thus, our results identify the OsTCP19-OsMYB108/OsMYB103L module as a key regulator of lignin and cellulose production in rice, and open up the possibility for precisely manipulating lignin-cellulose composition to improve culm mechanical properties for lodging resistance.

Two MADS-box genes regulate vascular cambium activity and secondary growth by modulating auxin homeostasis in Populus.

In trees, stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation, in which an auxin concentration gradient across the cambium area plays a crucial role in regulating the process. However, the underlying molecular mechanism for the establishment of auxin concentration is not fully understood. In this study, we identified two function-unknown MADS-box genes, VCM1 and VCM2, which are expressed specifically in the vascular cambium and modulate the subcellular homeostasis of auxin. Simultaneous knockdown of both VCM1 and VCM2 enhanced vascular cambium proliferation activity and subsequent xylem differentiation. Overexpression of VCM1 suppressed vascular cambium activity and wood formation by regulating PIN5 expression, which tuned the soluble auxin concentration in the vascular cambium area. This study reveals the role of VCM1 and VCM2 in regulating the proliferation activity of the vascular cambium and secondary growth by modulating the subcellular auxin homeostasis in Populus.