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The Cellulose synthase (CesA) and Cellulose synthase-like (Csl) gene superfamilies encode key enzymes involved in the synthesis of cellulose and hemicellulose, which are major components of plant cell walls, and play important roles in the regulation of fruit ripening. However, genome-wide identification and functional analysis of the CesA and Csl gene families in strawberry remain limited. In this study, eight CesA genes and 25 Csl genes were identified in the genome of diploid woodland strawberry (Fragaria vesca). The protein structures, evolutionary relationships, and cis-acting elements of the promoter for each gene were investigated. Transcriptome analysis and quantitative real-time PCR (qRT-PCR) results showed that the transcript levels of many FveCesA and FveCsl genes were significantly decreased during fruit ripening. Moreover, based on the transcriptome analysis, we found that the expression levels of many FveCesA/Csl genes were changed after nordihydroguaiaretic acid (NDGA) treatment. Transient overexpression of FveCesA4 in immature strawberry fruit increased fruit firmness and reduced fresh fruit weight, thereby delaying ripening. In contrast, transient expression of FveCesA4-RNAi resulted in the opposite phenotypes. These findings provide fundamental information on strawberry CesA and Csl genes and may contribute to the elucidation of the molecular mechanism by which FveCesA/Csl-mediated cell wall synthesis regulates fruit ripening. In addition, these results may be useful in strawberry breeding programs focused on the development of new cultivars with increased fruit shelf-life.

IntroductionHuman brucellosis is a severe public concern in Shaanxi Province, China, and investigating the epidemiological relationship and transmission pattern of B. melitensis is necessary to devise control strategies.MethodsIn this study, a conventional bio-typing approach and whole genome sequencing of single-nucleotide polymorphisms (SNPs) were employed to identify 189 strains.ResultsBased on the conventional bio-typing, 189 Brucella strains were identified as B. melitensis, of which 14 were in bv. 1, 145 were in bv. 3, and 30 were variant, and the Brucella strains were distributed in all ten cities in Shaanxi Province. SNP analysis was used to identify genetic variation in 189 B. melitensis genomes, and maximum-likelihood was used to generate a phylogeny that identified two clades (A and B) and 19 sequence types (STs). The two clades were highly diverse and exclusively of Eastern Mediterranean origin. Clade B contained 18 STs (2-19), with most isolates originating from a broad swath, implying that multiple B. melitensis lineages circulated in Shaanxi. The 19 STs were composed of 3 to 46 strains isolated from different counties and years, suggesting that multiple cross-county brucellosis outbreak events are driven by multiple B. melitensis lineages. Global phylogenetic analysis revealed that clade A was close to GTIIb, and clade B was placed in the GTIIh lineage, expanding the known diversity of B. melitensis from China.ConclusionThe human brucellosis epidemic in Shaanxi is driven by multiple indigenous circulating B. melitensis lineages, the knowledge of which will contribute to devising a control strategy and providing the foundation for a comprehensive regional phylogeny of this important zoonotic pathogen.

With the booming of worldwide agriculture intensification, brucellosis, one of the most neglected zoonotic diseases, has become an increasing challenge for global public health. Although the transmission patterns of human brucellosis (HB) have been studied in many regions, the dynamic transfer processes of risk and its driving factors remain poorly understood, especially in the context of agricultural intensification. This study attempted to explore the risk transfer of HB between the exact epidemic areas and the neighboring or distant low-risk areas to explain the impact of livestock agriculture intensification and foodborne infections on the transmission of HB in Shaanxi Province as a case study. We adopted multiple approaches, including test-based methods, model-based methods, and a geographical detector to detect the spatial-temporal dynamic changes of high-risk epidemic areas of HB at the county scale. We also quantitatively estimated how the related factors drove the risk transfer of the disease. Results confirmed the risk transfer pattern of HB with an expansion from north to south in Shaanxi Province and identified two primary transfer routes. In particular, in the traditional epidemic areas of the Shaanbei plateau, the farm agglomeration effect can significantly increase the risk of HB. Meanwhile, retail outlets for milk and dairy products were partially responsible for the foodborne infections of HB in the emerging epidemic areas of Xi'an. This study not only contributed helpful insights to support HB control and prevention in the rapid transition of livestock agriculture but also provided possible directions for further research on foodborne HB infections in urbanized areas.