RNAi technology is a versatile, effective, safe, and eco-friendly alternative for crop protection. There is plenty of evidence of its use through host-induced gene silencing (HIGS) and spray-induced gene silencing (SIGS) techniques to control viruses, bacteria, fungi, insects, and nematodes. For SIGS, its most significant challenge is achieving stability and avoiding premature degradation of RNAi in the environment or during its absorption by the target organism. One alternative is encapsulation in liposomes, virus-like particles, polyplex nanoparticles, and bioclay, which can be obtained through the recombinant production of RNAi in vectors, transgenesis, and micro/nanoencapsulation. The materials must be safe, biodegradable, and stable in multiple chemical environments, favoring the controlled release of RNAi. Most of the current research on encapsulated RNAi focuses primarily on oral delivery to control insects by silencing essential genes. The regulation of RNAi technology focuses on risk assessment using different approaches; however, this technology has positive economic, environmental, and human health implications for its use in agriculture. The emergence of alternatives combining RNAi gene silencing with the induction of resistance in crops by elicitation and metabolic control is expected, as well as multiple silencing and biotechnological optimization of its large-scale production.

The development of gamma rays mutant rice lines would be a solution for introducing variability in already farmer using varieties. In vitro gamma (60Co) mutagenesis reduces chimeras and allows a faster selection of desired traits but requires laboratory process optimization. The objective of the present work was the in vitro establishment of a recalcitrant rice embryogenic calli, the determination of its sensitivity to gamma radiation (Co-60), sequencing MATK and Rubisco for identification purposes, as well as generation optimization. The radiosensitivity of embryogenic calli resulted in an LD50 of 110Gy, while the 20% lethal dose was 64Gy. All sequenced genes matched perfectly with already reported MATK and Rubisco O. sativa genes with a clear SNP that identifies the local variety related to the southeast Asia Region. Callus induction improves with an MS with 2mg/L 2,4D, and the regeneration was achieved with an MS medium with 3mg/L BAP and 0,5mg/L NAA. The optimized radiation condition was 60Gy with an 83% regeneration in a semisolid medium, allowing a balance between mutation and regeneration. When increased to 80Gy, the regeneration rate falls to 29%. An immersion system (RITA®) of either 60 or 120 seconds every 8hours allowed a systematic and homogeneous total regeneration of the recalcitrant line, in contrast with the semisolid medium that resulted in positive but irregular regeneration. Other well-known recalcitrant cultivars, CR1821, CR1113 also had an improving regeneration in the immersion system, demonstrating its potential use for recalcitrant materials. To our knowledge, this is the first report on using an immersion system to allow regeneration of gamma-ray mutants from recalcitrant rice materials.

Parthenium incanum (Mariola) is used in Mexico to treat stomach and liver disorders. Reports have shown that the genus Parthenium contains biologically active metabolites. This work aimed to isolate and identify biologically active compounds with trypanocidal activity. The extracts were obtained through static maceration and extraction with successive reflux using different solvents. After that, they were fractionated with column chromatography, and the obtained fractions were compared by TLC; similar fractions were pooled and concentrated. A bioguided assay was performed with S. aureus ATCC 25923, using agar diffusion techniques and bioautography to determine preliminary biological activity. Active fractions were obtained and purified from a preparative TLC plate. The obtained compounds were identified as parthenin and coronopolin by TLC, FT-IR, and HPLC-MS. Finally, they were evaluated against the Ninoa strain of Trypanosoma cruzi, obtaining an IC50 of up to 45±2.5 ppm. It was concluded that P. incanum contains compounds with trypanocidal activity.