Exploring the influence of a single-nucleotide mutation in EIN4 on tomato fruit firmness diversity through fruit pericarp microstructure.

Tomato (Solanum lycopersicum) stands as one of the most valuable vegetable crops globally, and fruit firmness significantly impacts storage and transportation. To identify genes governing tomato firmness, we scrutinized the firmness of 266 accessions from core collections. Our study pinpointed an ethylene receptor gene, SlEIN4, located on chromosome 4 through a genome-wide association study (GWAS) of fruit firmness in the 266 tomato core accessions. A single-nucleotide polymorphism (SNP) (A → G) of SlEIN4 distinguished lower (AA) and higher (GG) fruit firmness genotypes. Through experiments, we observed that overexpression of SlEIN4AA significantly delayed tomato fruit ripening and dramatically reduced fruit firmness at the red ripe stage compared with the control. Conversely, gene editing of SlEIN4AA with CRISPR/Cas9 notably accelerated fruit ripening and significantly increased fruit firmness at the red ripe stage compared with the control. Further investigations revealed that fruit firmness is associated with alterations in the microstructure of the fruit pericarp. Additionally, SlEIN4AA positively regulates pectinase activity. The transient transformation assay verified that the SNP (A → G) on SlEIN4 caused different genetic effects, as overexpression of SlEIN4GG increased fruit firmness. Moreover, SlEIN4 exerts a negative regulatory role in tomato ripening by impacting ethylene evolution through the abundant expression of ethylene pathway regulatory genes. This study presents the first evidence of the role of ethylene receptor genes in regulating fruit firmness. These significant findings will facilitate the effective utilization of firmness and ripening traits in tomato improvement, offering promising opportunities for enhancing tomato storage and transportation capabilities.

A novel bioconversion for value-added products from food waste using Musca domestica.

Food waste, as a major part of the municipal solid waste has been generated increasingly worldwide. Efficient and feasible utilization of this waste material for productivity process is significant for both economical and environmental reasons. In the present study, Musca domestica larva was used as the carrier to conduct a bioconversion with food waste to get the value-added maggot protein, oil and organic fertilizers. Methods of adult flies rearing, culture medium adjuvant selection, maggot culture conditions, stocking density and the valorization of the waste have been explored. From the experimental results, every 1000g culture mediums (700g food waste and 300g adjuvant) could be disposed by 1.5g M. domestica eggs under proper culture conditions after emergence in just 4days, 42.95±0.25% of which had been consumed and the culture medium residues could be used as good organic fertilizers, accompanying with the food waste consumption, ∼53.08g dried maggots that contained 57.06±2.19% protein and 15.07±2.03% oil had been produced. The maggot protein for its outstanding pharmacological activities is regarded as a good raw material in the field of medicine and animal feeding. Meanwhile, the maggot oil represents a potential alternative feedstock for biodiesel production. In our study, the maggot biodiesel was obtained after the procedure of transesterification reaction with methanol and the productivity was 87.71%.