Agri-biotechnology of coriander (Coriandrum sativum L.): an inclusive appraisal

Metal-immobilizing Pseudomonas taiwanensis WRS8 reduces heavy metal accumulation in Coriandrum sativum by changing the metal immobilization-related bacterial population abundances

Metal-immobilizing bacteria play a critical role in metal accumulation in vegetables. However, little is known concerning the mechanisms involved in bacteria-induced reduced metal availability and uptake in vegetables. In this study, the impacts of metal-immobilizing Pseudomonas taiwanensis WRS8 on the plant biomass, Cd and Pb availability and uptake in two coriander (Coriandrum sativum L.) cultivars, and bacterial community structure were investigated in the polluted soil. Strain WRS8 increased the biomass of two coriander cultivars by 25-48% and reduced Cd and Pb contents in the edible tissues by 40-59% and available Cd and Pb contents in the rhizosphere soils by 11.1-15.2%, compared with the controls. Strain WRS8 significantly increased the pH values and relative abundances of the dominant populations of Sphingomonas, Pseudomonas, Gaiellales, Streptomyces, Frankiales, Bradyrhizobium, and Luteimonas, while strain WRS8 significantly decreased the relative abundances of the dominant populations of Gemmatimonadaceae, Nitrospira, Haliangium, Paenibacillus, Massilia, Bryobacter, and Rokubacteriales and the rare bacterial populations of Enterorhabdus, Roseburia, Luteibacter, and Planifilum in the rhizosphere soils, compared with the controls. Significantly negative correlations were observed between the available metal concentrations and the abundances of Pseudomonas, Luteimonas, Frankiales, and Planifilum. These results implied that strain WRS8 could affect the abundances of the dominant and rare bacterial populations involved in metal immobilization, resulting in increased pH values and decreased metal availability and uptake in the vegetables in the contaminated soil.

Advancements and prospectives of sugar beet (Beta vulgaris L.) biotechnology

Sugar beet (Beta vulgaris L.) is the second largest sugar-producing crop (following sugarcane), accounting around 40% of total global sugar output. It has been reckoned with huge contribution in sugar, ethanol, and fodder industries. Since sugar beet is recalcitrant in nature, to address the multifaceted difficulties associated with its conventional propagation, several biotechnological tools and techniques aiming with in vitro-based mass regeneration-cum-genetic enhancement are becoming popular. The implementation of effective methodology for in vitro regeneration from ex vitro explant sources becomes the necessity for successful commercial-scale clonal propagation and genetic modification. Substantial research achievements have been made in the past few decades in connection to the optimization of in vitro protocols for direct and callus-mediated regeneration, homozygous line production, somatic hybridization, and genetic transformation of sugar beet. The current review summarizes several reported findings on various physio-chemical factors responsible for direct, indirect organogenesis, somatic embryogenesis, protoplast culture, haploid culture, acclimatization accountable for plantlet mass multiplication, assessing the genetic integrity of in vitro-cultured plantlets, and, finally, successful transgenic approaches to remediate biotic and abiotic stresses. Furthermore, this study highlights undiscovered regions, research gaps, and major bottlenecks that might be considered in developing significant innovative ideas related to sugar beet biotechnology in the near future. KEY POINTS: • Sugar beet, the second largest sugar producer, is a major contributor in sugar, ethanol, and fodder industries. • Current review comprehensively evaluates diverse factors influencing the success of in vitro biotechnological interventions. • This review further highlights the research gaps and offers way outs to attain comprehensive genetic improvement.

Biotechnology of banana (Musa spp.): multi-dimensional progress and prospect of in vitro-mediated system

Banana (Musa spp.), commonly known as 'Adam fig' and 'Fruit of wise man', is a commercial herbaceous tropical fruit, which governs its antiquity from ancient periods in the Indian and African subcontinent. All parts of the plant, i.e. stem, leaf, root, inflorescence, peel, fruit, and flower, have significant medicinal and nutritional values. Owing to its multitude of uses, it is known as 'Kalpavriksha' (plant of virtues). To combat multi-faceted issues related to traditional propagation, in vitro-based regeneration-cum-genetic improvement approaches become the trend of the hour. The present review illustrates various physico-chemical factors that are responsible for successful in vitro regeneration and acclimatization, protoplast culture, anther and microspore culture, cryopreservation and synthetic seed production, genetic transformation, mutagenesis, and nanotechnological and omics approaches. The key intent of this article is to present an insight on in vitro biotechnological research advances in the past decade, to identify the research gaps, unexplored areas, and major shortcomings associated with banana biotechnology and to highlight the potential approaches to mitigate them. Eventually, this review made salient conclusions and recommendations paving the way forward for the banana researchers to develop innovative ideas in order to enhance the propagation frequency and to ensure the genetic improvement of banana. KEY POINTS: • This review addresses biotechnological interventions in Banana (Musa spp.) for enhanced propagation and quality improvement. • Highlights factors influencing in vitro regeneration, conservation, and genetic transformation. • Provides novel ideas to harness the qualitative and quantitative genetic improvement.