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Sorghum, also known as great millet, is a major cereal crop that feeds over 500 million people in more than 100 countries, especially in Africa and Asia. It can grow well under harsh environmental conditions, such as drought, heat, salinity, and soils that are nutritionally poor. The crop is water- and nitrogen-efficient with C4 photosynthesis system and a relatively small genome of about 730 Mb. Its genome has been sequenced and annotated, revealing significant genetic variation and genomics resources. Despite being drought tolerant, there is a great degree of variation among the diverse lines of germplasm for drought and drought associated traits, and hence resilience to drought and other stresses need to be studied through the integration of phenomics and genomics technologies. There is an urgent need to adopt advanced genomics and high-throughput technologies to find candidate genes and alleles for crop traits, develop molecular markers and genomic selection (GS) models, create new genetic variation and design sorghum ideotypes that suit to the changing climate.

Systematic genome-wide analysis of Sorghum bicolor revealed the identification of a total of 48 homologous genes comprising 21 proline-rich proteins (PRPs) and 27 hybrid proline-rich proteins (HyPRPs). Comprehensive scrutiny of these gene homologs was conducted for gene structure, phylogenetic investigations, chromosome mapping, and subcellular localization of proteins. Promoter analysis uncovered the regions rich with phosphorous- (BIHD), ammonium-, sulfur-responsive (SURE), and iron starvation-responsive (IRO2) along with biotic, abiotic, and development-specific cis-elements. Further, PRPs exhibit more methylation and acetylation sites in comparison with HyPRPs. miRNAs have been predicted which might play a role in cleavage and translation inhibition. Several of the SbPRP genes were stimulated in a tissue-specific manner under drought, salt, heat, and cold stresses. Additionally, exposure of plants to abscisic acid (ABA) and zinc (Zn) also triggered PRP genes in a tissue-dependent way. Among them, SbPRP17 has been found upregulated markedly in all tissues irrespective of the stress imposed. The expressions of SbHyPRPs, especially SbHyPRP2, SbHyPRP6, and SbHyPRP17 were activated under all stresses in all three tissues. On the other hand, SbHyPRP8 (root only) and SbHyPRP12 (all three tissues) were highly responsive to cold stress and ABA while SbHyPRP26 was induced by drought and Zn in the stem. Taken together, this study indicates the critical roles that SbPRPs and SbHyPRPs play during diverse abiotic stress conditions and notably the plausible roles that these genes play upon exposure to zinc, the crucial micronutrient in plants.

Plants have long been exploited as a sustainable source of food, flavors, agrochemicals, colors, therapeutic proteins, bioactive compounds, and stem cell production. However, plant habitats are being briskly lost due to scores of environmental factors and human disturbances. This necessitates finding a viable alternative technology for the continuous production of compounds that are utilized in food and healthcare. The high-value natural products and bioactive compounds are often challenging to synthesize chemically since they accumulate in meager quantities. The isolation and purification of bioactive compounds from plants is time-consuming, labor-intensive, and involves cumbersome extraction procedures. This demands alternative options, and the plant cell culture system offers easy downstream procedures. Retention of the metabolic cues of natural plants, scale-up facility, use as stem cells in the cosmetics industry, and metabolic engineering (especially the rebuilding of the pathways in microbes) are some of the advantages for the synthesis and accumulation of the targeted metabolites and creation of high yielding cell factories. In this article, we discuss plant cell suspension cultures for the in vitro manipulation and production of plant bioactive compounds. Further, we discuss the new advances in the application of plant cells in the cosmetics and food industry and bioprinting.

Fruit species contribute to nutritional and health security by providing micronutrients, antioxidants, and bioactive phytoconstituents, and hence fruit-based products are becoming functional foods presently and for the future. Although conventional breeding methods have yielded improved varieties having fruit quality, aroma, antioxidants, yield, and nutritional traits, the threat of climate change and need for improvement in several other traits such as biotic and abiotic stress tolerance and higher nutritional quality has demanded complementary novel strategies. Biotechnological research in fruit crops has offered immense scope for large-scale multiplication of elite clones, in vitro, mutagenesis, and genetic transformation. Advanced molecular methods, such as genome-wide association studies (GWAS), QTLomics, genomic selection for the development of novel germplasm having functional traits for agronomic and nutritional quality, and enrichment of bioactive constituents through metabolic pathway engineering and development of novel products, are now paving the way for trait-based improvement for developing genetically superior varieties in fruit plant species for enhanced nutritional quality and agronomic performance. In this article, we highlight the applications of in vitro and molecular breeding approaches for use in fruit breeding.

Recent years have witnessed a gradual increase in the bioavailability and groundwater leaching of toxic heavy metals (HMs) in the environment, driven mainly by anthropogenic invasions. HMs, especially ranked as toxic/carcinogenic non-essential ones including Cadmium (Cd), Arsenic (As), Aluminium (Al), Mercury (Hg) and Lead (Pb) have emerged as the major soil, air and water contaminants affecting food production, quality and security worldwide. HMs affect plant growth and crop yield. Plants have developed intricate defense mechanisms for safeguarding themselves against the toxic effects imposed by HMs, including compartmentalization and sequestration in cell-organelles, inactivation by complex formation with the organic ligands and their exclusion using transporters, ion channels, transcription factors and signaling molecules, beside others. Omics approaches have generated significant resources and updates on the plant genome, transcriptome and metabolome plasticity against HM-induced stress stimuli. Omics technologies are pragmatic and seen as feasible approaches for characterizing the roles of genomes (genomics), coding (transcriptomics) and non-coding (miRNAomics) RNA transcripts, and metabolites (metabolomics) including metals (metallomics), which can ultimately be used for improving stress tolerance or generating resilience plant systems. This review aims to summarize the current understandings on the mechanistic insights of selected toxic (Cd, As, Al, Hg and Pb) HM-plant interactions, including their uptake, transport, toxicity and chelation/sequestration in cellular components, besides how plants respond and adapt to these stress factors. State-of-the-art in Omics approaches including genomics, transcriptomics, metabolomics, miRNAomics and metallomics for plant HM research have been presented. Present status, challenges and future prospects are also discussed.

In vitro mutagenesis offers a feasible approach for developing new orchid cultivars through genetic manipulation. In the present study, protocorm-like bodies (PLBs) were exposed to gamma rays (10, 20, 40, 60, 80 Gy) to study in vitro growth responses and induction of mutants in Dendrobium ‘Emma White’. Both proliferation and regeneration of PLBs decreased progressively with increasing doses, except for a significantly enhanced growth response at 10 Gy. The optimal dose of gamma radiation for mutagenesis was found in the range 10 to 25 Gy based on the growth reduction curve. Analysis using a high-throughput cell analyzer revealed a significant reduction in nuclear DNA content at > 40 Gy doses. At 10 Gy treatment, the growth attributes, such as root length, plant height and leaf number, were significantly increased by 36%, 26% and 20%, respectively, compared to the control. This increase was significant over other tested doses as well. Testing of random amplified polymorphic DNA markers revealed the presence of detectable polymorphism among gamma mutant plantlets with a polymorphism information content value at 0.41. The gamma-ray-induced earliness in flower development was observed within 294 days post ex vitro growth of 10 Gy mutant compared to the control plants flowered after 959 days. Our results highlight the significance of gamma radiation in inducing enhanced growth, morphological variations and early floral initiation in Dendrobium, providing a basic framework for mutation breeding and improvement of orchids.