AtSYP71 Is Important for Plant Cell Wall Biosynthesis and Stress Adaptation.

Background: SYP71, the plant-specific Qc-SNARE protein, is reported to regulate vesicle trafficking. SYP71 is localized on the ER, endosome, plasma membrane and cell plate, suggesting its multiple functions. Lotus SYP71 is essential for symbiotic nitrogen fixation in nodules. AtSYP71, GmSYP71 and OsSYP71 are implicated in plant resistance to pathogenesis. To date, SYP71 regulatory role on plant development remain unclear.Results: AtSYP71-knockout mutant atsyp71-4 was lethal at early development stage. Early development of AtSYP71-knockdown mutant atsyp71-2 was delayed, and stress response was also affected. Confocal images revealed that protein secretion was blocked in atsyp71-2. Transcriptomic analysis indicated that metabolism, response to environmental stimuli pathways and apoplast components were influenced in atsyp71-2. Moreover, the contents of lignin, cellulose and flavonoids as well as cell wall structures were also altered.Conclusion: Our findings suggested that AtSYP71 is essential for plant development. AtSYP71 probably regulates plant development, metabolism and environmental adaptation by affecting cell wall homeostasis via mediating secretion of materials and regulators required for cell wall biosynthesis and dynamics.

Temporal Gene Expression in Apical Culms Shows Early Changes in Cell Wall Biosynthesis Genes in Sugarcane

Multiple genes in sugarcane control sucrose accumulation and the biosynthesis of cell wall components; however, it is unclear how these genes are expressed in its apical culms. To better understand this process, we sequenced mRNA from +1 stem internodes collected from four genotypes with different concentrations of soluble solids. Culms were collected at four different time points, ranging from six to 12-month-old plants. Here we show differentially expressed genes related to sucrose metabolism and cell wall biosynthesis, including genes encoding invertases, sucrose synthase and cellulose synthase. Our results showed increased expression of invertases in IN84-58, the genotype with lower sugar and higher fiber content, as well as delayed expression of secondary cell wall-related cellulose synthase for the other genotypes. Interestingly, genes involved with hormone metabolism were differentially expressed across time points in the three genotypes with higher soluble solids content. A similar result was observed for genes controlling maturation and transition to reproductive stages, possibly a result of selection against flowering in sugarcane breeding programs. These results indicate that carbon partitioning in apical culms of contrasting genotypes is mainly associated with differential cell wall biosynthesis, and may include early modifications for subsequent sucrose accumulation. Co-expression network analysis identified transcription factors related to growth and development, showing a probable time shift for carbon partitioning occurred in 10-month-old plants.

JMM Profile: Carbapenems: a broad-spectrum antibiotic

Carbapenems are potent members of the β-lactam family that inhibit bacterial cell-wall biosynthesis inhibitors . They are highly effective against Gram-negative and Gram-positive drug-resistant infections . As such, carbapenems are typically reserved as an antibiotic of last resort. The WHO lists meropenem as an essential medicine. Nausea and vomiting are reported in ≤20% of carbapenem recipients, with 1.5% suffering seizures. Enzymatic hydrolysis of the β-lactam ring is the main driver of clinical resistance. These enzymes can be classified as Class A, B and D. Classes A and D are serine β-lactamases, whereas Class B rely on metal-mediated hydrolysis, typically through zinc.

Deep transcriptomic study reveals the role of cell wall biosynthesis and organization networks in the developing shell of peanut pod

Background Peanut (Arachis hypogaea L.) belongs to an exceptional group of legume plants, wherein the flowers are produced aerially, but the pods develop under the ground. In such a unique environment, the pod’s outer shell plays a vital role as a barrier against mechanical damage and soilborne pathogens. Recent studies have reported the uniqueness and importance of gene expression patterns that accompany peanut pods’ biogenesis. These studies focused on biogenesis and pod development during the early stages, but the late developmental stages and disease resistance aspects still have gaps. To extend this information, we analyzed the transcriptome generated from four pod developmental stages of two genotypes, Hanoch (Virginia-type) and IGC53 (Peruvian-type), which differs significantly in their pod shell characteristics and pathogen resistance. Results The transcriptome study revealed a significant reprogramming of the number and nature of differentially expressed (DE) genes during shell development. Generally, the numbers of DE genes were higher in IGC53 than in Hanoch, and the R5-R6 transition was the most dynamic in terms of transcriptomic changes. Genes related to cell wall biosynthesis, modification and transcription factors (TFs) dominated these changes therefore, we focused on their differential, temporal and spatial expression patterns. Analysis of the cellulose synthase superfamily identified specific Cellulose synthase (CesAs) and Cellulose synthase-like (Csl) genes and their coordinated interplay with other cell wall-related genes during the peanut shell development was demonstrated. TFs were also identified as being involved in the shell development process, and their pattern of expression differed in the two peanut genotypes. The shell component analysis showed that overall crude fiber, cellulose, lignin, hemicelluloses and dry matter increased with shell development, whereas K, N, protein, and ash content decreased. Genotype IGC53 contained a higher level of crude fiber, cellulose, NDF, ADF, K, ash, and dry matter percentage, while Hanoch had higher protein and nitrogen content. Conclusions The comparative transcriptome analysis identified differentially expressed genes, enriched processes, and molecular processes like cell wall biosynthesis/modifications, carbohydrate metabolic process, signaling, transcription factors, transport, stress, and lignin biosynthesis during the peanut shell development between two contrasting genotypes. TFs and other genes like chitinases were also enriched in peanut shells known for pathogen resistance against soilborne major pathogens causing pod wart disease and pod damages. This study will shed new light on the biological processes involved with underground pod development in an important legume crop.

Unipolar Peptidoglycan Synthesis in the Rhizobiales Requires an Essential Class A Penicillin-Binding Protein

While the structure and function of the bacterial cell wall are well conserved, the mechanisms responsible for cell wall biosynthesis during elongation are variable. It is increasingly clear that rod-shaped bacteria use a diverse array of growth strategies with distinct spatial zones of cell wall biosynthesis, including lateral elongation, unipolar growth, bipolar elongation, and medial elongation.

Temporal Gene Expression in Apical Culms Shows Early Changes in Cell Wall Biosynthesis Genes in Sugarcane

Multiple genes in sugarcane control sucrose accumulation and the biosynthesis of cell wall components; however, it is unclear how these genes are expressed in its apical culms. To better understand this process, we sequenced mRNA from +1 stem internodes collected from four genotypes with different concentrations of soluble solids. Culms were collected at four different time points, ranging from six to 12-month-old plants. Here we show differentially expressed genes related to sucrose metabolism and cell wall biosynthesis, including genes encoding invertases, sucrose synthase and cellulose synthase. Our results showed increased expression of invertases in IN84-58, the genotype with lower sugar and higher fiber content, as well as delayed expression of secondary cell wall-related cellulose synthase for the other genotypes. Interestingly, genes involved with hormone metabolism were differentially expressed across time points in the three genotypes with higher soluble solids content. A similar result was observed for genes controlling maturation and transition to reproductive stages, possibly a result of selection against flowering in sugarcane breeding programs. These results indicate that carbon partitioning in apical culms of contrasting genotypes is mainly associated with differential cell wall biosynthesis, and may include early modifications for subsequent sucrose accumulation. Co-expression network analysis identified transcription factors related to growth and development, showing a probable time shift for carbon partitioning occurred in 10-month-old plants.