Microalgae, due to their complex metabolic capacity, are being continuously explored for nutraceuticals, pharmaceuticals, and other industrially important bioactives. However, suboptimal yield and productivity of the bioactive of interest in local and robust wild-type strains are of perennial concerns for their industrial applications. To overcome such limitations, strain improvement through genetic engineering could play a decisive role. Though the advanced tools for genetic engineering have emerged at a greater pace, they still remain underused for microalgae as compared to other microorganisms. Pertaining to this, we reviewed the progress made so far in the development of molecular tools and techniques, and their deployment for microalgae strain improvement through genetic engineering. The recent availability of genome sequences and other omics datasets form diverse microalgae species have remarkable potential to guide strategic momentum in microalgae strain improvement program. This review focuses on the recent and significant improvements in the omics resources, mutant libraries, and high throughput screening methodologies helpful to augment research in the model and non-model microalgae. Authors have also summarized the case studies on genetically engineered microalgae and highlight the opportunities and challenges that are emerging from the current progress in the application of genome-editing to facilitate microalgal strain improvement. Toward the end, the regulatory and biosafety issues in the use of genetically engineered microalgae in commercial applications are described.

Medicinal and aromatic plants (MAPs) are a rich source of bioactive compounds that are immensely important due to their potential use in pharmacological and agricultural applications. Here, we have evaluated the antimicrobial activity of essential oils (EOs) from three different species of Ocimum: O. gratissimum (EO1), O. tenuiflorum (EO2), and O. sanctum (EO3). The EOs were screened for antibacterial activity against pathogenic strains of Escherichia coli, Enterobacter cloacae and methicillin-resistant Staphylococcus aureus (MRSA). The essential oils EO1 and EO3 showed significant growth inhibition of the tested bacteria. Likewise, all EOs exhibited antifungal potential against the broad-spectrum plant fungal pathogen Sclerotinia sclerotiorum that causes white-mould disease in plants. Moreover, the antimicrobial potential of the EOs correlates well with their antioxidant activity determined by DPPH free radical scavenging activity. The biochemical analysis of the EOs employing high-performance thin-layer chromatography, gas chromatography-mass spectrometry, and Fourier transform infrared spectroscopy, revealed the presence of distinct phytoconstituents that might be responsible for their differential bioactivity. Furthermore, an in-silico evaluation of the candidate phytoconstituents using molecular docking analysis suggests their potential for antimicrobial applications. Altogether, our results clearly show that EO1 and EO3 possess promising antimicrobial properties, and therefore could be utilized as a potential antimicrobial agent.

Hybrid proline-rich proteins (HyPRPs) belong to the family of 8-cysteine motif (8CM) containing proteins that play important roles in plant development processes, and tolerance to biotic and abiotic stresses. To gain insight into the rice HyPRPs, we performed a systematic genome-wide analysis and identified 45 OsHyPRP genes encoding 46 OsHyPRP proteins. The phylogenetic relationships of OsHyPRP proteins with monocots (maize, sorghum, and Brachypodium) and a dicot (Arabidopsis) showed clustering of the majority of OsHyPRPs along with those from other monocots, which suggests lineage-specific evolution of monocots HyPRPs. Based on our previous RNA-Seq study, we selected differentially expressed OsHyPRPs genes and used quantitative real-time-PCR (qRT-PCR) to measure their transcriptional responses to biotic (Magnaporthe oryzae) and abiotic (heat, cold, and salt) stresses and hormone treatment (Abscisic acid; ABA, Methyl-Jasmonate; MeJA, and Salicylic acid; SA) in rice blast susceptible Pusa Basmati-1 (PB1) and blast-resistant near-isogenic line PB1+Pi9. The induction of OsHyPRP16 expression in response to the majority of stresses and hormonal treatments was highly correlated with the number of cis-regulatory elements present in its promoter region. In silico docking analysis of OsHyPRP16 showed its interaction with sterols of fungal/protozoan origin. The characterization of the OsHyPRP gene family enables us to recognize the plausible role of OsHyPRP16 in stress tolerance.

Rice is a staple food crop for almost half of the world’s population, especially in the developing countries of Asia and Africa. It is widely grown in different climatic conditions, depending on the quality of the water, soil, and genetic makeup of the rice cultivar. Many (a)biotic stresses severely curtail rice growth and development, with an eventual reduction in crop yield. However, for molecular functional analysis, the availability of an efficient genetic transformation protocol is essential. To ensure food security and safety for the continuously increasing global population, the development of climate-resilient crops is crucial. Here, in this study, the rice transformation protocol has been effectively optimized for the efficient and rapid generation of rice transgenic plants. We also highlighted the critical steps and precautionary measures to be taken while performing the rice transformation. We further assess the efficacy of this protocol by transforming rice with two different transformation constructs for generating galactinol synthase (GolS) overexpression lines and CRISPR/Cas9-mediated edited lines of lipase (Lip) encoding the OsLip1 gene. The putative transformants were subjected to molecular analysis to confirm gene integration/editing, respectively. Collectively, the easy, efficient, and rapid rice transformation protocol used in this present study can be applied as a potential tool for gene(s) function studies in rice and eventually to the rice crop improvement.