The trichome-specific acetolactate synthase NtALS1 gene, is involved in acylsugar biosynthesis in tobacco (Nicotiana tabacum L.).

MAIN CONCLUSION: NtALS1 is specifically expressed in glandular trichomes, and can improve the content of acylsugars in tobacco. ABTRACT: The glandular trichomes of many species in the Solanaceae family play an important role in plant defense. These epidermal outgrowths exhibit specialized secondary metabolism, including the production of structurally diverse acylsugars that function in defense against insects and have substantial developmental potential for commercial uses. However, our current understanding of genes involved in acyl chain biosynthesis of acylsugars remains poor in tobacco. In this study, we identified three acetolactate synthase (ALS) genes in tobacco through homology-based gene prediction using Arabidopsis ALS. Quantitative real-time PCR (qRT-PCR) and tissue distribution analyses suggested that NtALS1 was highly expressed in the tips of glandular trichomes. Subcellular localization analysis showed that the NtALS1 localized to the chloroplast. Moreover, in the wild-type K326 variety background, we generated two ntals1 loss-of-function mutants using the CRISPR-Cas9 system. Acylsugars contents in the two ntals1 mutants were significantly lower than those in the wild type. Through phylogenetic tree analysis, we also identified NtALS1 orthologs that may be involved in acylsugar biosynthesis in other Solanaceae species. Taken together, these findings indicate a functional role for NtALS1 in acylsugar biosynthesis in tobacco.

Assessment of postoperative adhesion formation in a rat cecum model using different techniques.

Adhesion-related complications after abdominal surgery bring out momentous morbidity and costs. Outcomes from animal experiments investigating prevention of adhesions are limited due to lack of consistency in existing animal models. Different intraperitoneal adhesion models were compared the inter observer variability was evaluated to seek for best model. Forty male SD rats weighting 250-300g were included and assigned randomly to four groups with diverse techniques, (A) postoperative adhesion cecum rat model abraded with sterile rasp; (B) postoperative adhesion cecum rat model abraded with sterile dry gauze; (C) postoperative adhesion cecum rat model abraded with sterile blade; (D) postoperative adhesion cecum rat model abraded with vascular clamp. Macroscopic adhesion scores were evaluated by Bigatti scoring system, and the incidence of adhesion were surveyed on the 7th day after the surgery. The results showed that four techniques currently used Bigatti adhesion scoring system are subjective, the sterile rasp is the most consistent and reproducible tool to establish an intraperitoneal adhesion model which is helpful for related studies and the development of new substances for adhesion prevention in the future.