Boon Chin Tan

Effects of Selected Physicochemical Parameters on Zerumbone Production of Zingiber zerumbet Smith Cell Suspension Culture

Zingiber zerumbet Smith is an important herb that contains bioactive phytomedicinal compound, zerumbone. To enhance cell growth and production of this useful compound, we investigated the growth conditions of cell suspension culture. Embryogenic callus generated from shoot bud was used to initiate cell suspension culture. The highest specific growth rate of cells was recorded when it was cultured in liquid Murashige and Skoog basal medium containing 3% sucrose with pH 5.7 and incubated under continuous shaking condition of 70 rpm for 16 h light and 8 h dark cycle at 24°C. Our results also revealed that the type of carbohydrate substrate, light regime, agitation speed, and incubation temperature could affect the production of zerumbone. Although the zerumbone produced in this study was not abundant compared to rhizome of Z. zerumbet, the possibility of producing zerumbone during early stage could serve as a model for subsequent improvement.

Proteomics in commercial crops: An overview

Proteomics is a rapidly growing area of biological research that is positively affecting plant science. Recent advances in proteomic technology, such as mass spectrometry, can now identify a broad range of proteins and monitor their modulation during plant growth and development, as well as during responses to abiotic and biotic stresses. In this review, we highlight recent proteomic studies of commercial crops and discuss the advances in understanding of the proteomes of these crops. We anticipate that proteomic-based research will continue to expand and contribute to crop improvement. SIGNIFICANCE Plant proteomics study is a rapidly growing area of biological research that is positively impacting plant science. With the recent advances in new technologies, proteomics not only allows us to comprehensively analyses crop proteins, but also help us to understand the functions of the genes. In this review, we highlighted recent proteomic studies in commercial crops and updated the advances in our understanding of the proteomes of these crops. We believe that proteomic-based research will continue to grow and contribute to the improvement of crops.

Distribution of Flavonoids and Cyclohexenyl Chalcone Derivatives in Conventional Propagated and In Vitro-Derived Field-Grown Boesenbergia rotunda (L.) Mansf.

The distribution patterns of flavonoids and cyclohexenyl chalcone derivatives in conventional propagated (CP) and in vitro-derived (CPA) field-grown plants of an important medicinal ginger, Boesenbergia rotunda, are described. A total of eight compounds were extracted from six organs (rootlet, rhizome, shoot base, maroon stem, stalk, and leaf) of the CP and CPA plants. Five major chromatographic peaks, namely, alpinetin, pinocembrin, pinostrobin, 4-hydroxypanduratin A, and panduratin A, were consistently observed by high performance liquid chromatography. Nonaerial organs had higher levels of flavonoids than the aerial ones for all types of samples. Among the compounds detected, pinostrobin and 4-hydroxypanduratin A were the most abundant flavonoid and cyclohexenyl chalcone derivative, respectively. The distribution and abundance of the bioactive compounds suggested that the shoot base could be more potentially useful for medicinal application than other organs of the plant and may be the site of storage or occurrence of biosynthetic enzymatic activities.

A to Z on Banana Micropropagation and Field Practices

In order to stay competitive in the global banana production, it is important to ensure that the planting materials used have consistent superior agronomic traits and are disease-free and grown in farms with good agricultural practice. The use of suckers from field-grown plants as planting materials may increase the risk in the spread of diseases and inconsistent quality. Hence, the adoption of plant tissue culture technique for mass propagation of banana planting materials has been widely used. Micropropagation of bananas has been successfully established through the use of shoot or meristem cultures and inflorescence either through direct plant regeneration or establishment of regenerable cell suspension cultures. From the cell suspension cultures, single-celled protoplasts have also been isolated and regenerated. Not only the in vitro systems developed through tissue culture provide efficient plant production but also a platform for genetic engineering for agronomic traits improvement. In this chapter, we highlight studies on banana micropropagation and field practices of this important crop.

Stable integration of mgfp5 transgenes following Agrobacterium-mediated transformation in Boesenbergia rotunda cell suspension culture

Boesenbergia rotunda, a herb in the ginger family, contains numerous beneficial compounds, such as flavonoids, flavones and cyclohexenyl chalcone derivatives, that have great potential for pharmaceutical applications. However, the low concentration of the bioactive compounds limits their commercial application. In this study, a simple and reliable Agrobacterium-mediated transformation protocol for B. rotunda cell suspension culture was successfully developed. The minimal inhibitory concentration and natural tolerance of the selective agent, hygromycin, against the cells were 20 mg l−l and 30 mg l−l in liquid media and solid media, respectively. The highest number of transformed regenerants (18 ± 0.00 per ml settled cell volume) was recorded when cells were infected with Agrobacterium tumefaciens harbouring pCAMBIA1304 for 10 min and co-cultivated for 2 days. Prolonged infection time (> 10 min) and co-cultivation period (> 2 days), however, did not increase the transformation efficiencies. The results clearly show that infection and co-cultivation periods strongly influenced the transformation efficiency in ginger. The transformed cells were recovered and showed green fluorescent signals under ultraviolet excitation. An intense blue colour was observed in the transformed cells after β-glucuronidase (GUS) histochemical staining, further confirming the functionality of the GUS enzymes in the regenerants. Polymerase chain reaction analysis of 3-, 6-, 9- and 12-month-old transformed cells confirmed that the protocol enabled stable integration of the mgfp5 gene. Moreover, the comparatively high number of transformed regenerants in this study made it possible to generate a large number of transgenic cells in a short period, which would be useful for high-throughput functional screening of enzymes involved in the biosynthetic pathways of bioactive compounds.