Why plasma-activated water treatment reduced the malonaldehyde content in muscle foods.

An interesting phenomenon that plasma-activated water (PAW) treatment reduced the malonaldehyde (MDA) content in muscle foods was observed in both previous reports and the present study. However, the mechanism remains unclear. To clarify the theoretical basis of this phenomenon, the main reactive components in PAW were determined, and the changes in the fatty acid profile in tuna muscle after PAW treatment were analyzed. The results showed that the MDA content reduction upon PAW treatment was not due to the inhibition of lipid oxidation. To mimic the possible reaction of the components in PAW with MDA, individual hydrogen peroxide, nitrite, and nitrate or their mixture solution were added into MDA standard and tuna muscle. The results showed that the reaction of nitrite in PAW with MDA occurred during its measurement processes caused its reduction. The results in this work fully explained why PAW treatment reduced the MDA content in muscle foods.

A FLASH pipeline for arrayed CRISPR library construction and the gene function discovery of rice receptor-like kinases.

Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9)-mediated gene editing is revolutionizing plant research and crop breeding. Here, we present an effective and streamlined pipeline for arrayed CRISPR library construction and demonstrate it is suitable for small- to large-scale genome editing in plants. This pipeline introduces artificial PCR fragment-length markers for distinguishing guide RNAs (gRNAs) (FLASH), and a group of 12 constructs harboring different FLASH tags are co-transformed into plants each time. The identities of gRNAs in Agrobacterium mixtures and transgenic plants can therefore be read out by detecting the FLASH tags, a process that requires only conventional PCR and gel electrophoresis rather than sequencing. We generated an arrayed CRISPR library targeting all 1,072 members of the receptor-like kinase (RLK) family in rice. One-shot transformation generated a mutant population that covers gRNAs targeting 955 RLKs, and 74.3% (710/955) of the target genes had three or more independent T0 lines. Our results indicate that the FLASH tags act as bona fide surrogates for the gRNAs and are tightly (92.1%) associated with frameshift mutations in the target genes. In addition, the FLASH pipeline allows for rapid identification of unintended editing events without corresponding T-DNA integrations and generates high-order mutants of closely related RLK genes. Furthermore, we showed that the RLK mutant library enables rapid discovery of defense-related RLK genes. This study introduces an effective pipeline for arrayed CRISPR library construction and provides genome-wide rice RLK mutant resources for functional genomics.