development-cabbage-protoplast-system-for-studying-hypoxia-tolerance

Development of a Cabbage Protoplast System for Studying Hypoxia Tolerance in <i>Brassica</i>

As climate change brings more heavy rainfall, cabbage, a key Brassicaceae vegetable, faces significant yield losses due to flooding-induced hypoxia ...

National Taiwan University

Pseudomonas taiwanensis is a broad-host-range entomopathogenic bacterium that exhibits insecticidal activity toward agricultural pests Plutella xylostella, Spodoptera exigua, Spodoptera litura, Trichoplusia ni and Drosophila melanogaster. Oral infection with different concentrations (OD = 0.5 to 2) of wild-type P. taiwanensis resulted in insect mortality rates that were not significantly different (92.7%, 96.4% and 94.5%). The TccC protein, a component of the toxin complex (Tc), plays an essential role in the insecticidal activity of P. taiwanensis. The ΔtccC mutant strain of P. taiwanensis, which has a knockout mutation in the tccC gene, only induced 42.2% mortality in P. xylostella, even at a high bacterial dose (OD = 2.0). TccC protein was cleaved into two fragments, an N-terminal fragment containing an Rhs-like domain and a C-terminal fragment containing a Glt symporter domain and a TraT domain, which might contribute to antioxidative stress activity and defense against macrophagosis, respectively. Interestingly, the primary structure of the C-terminal region of TccC in P. taiwanensis is unique among pathogens. Membrane localization of the C-terminal fragment of TccC was proven by flow cytometry. Sonicated pellets of P. taiwanensis ΔtccC strain had lower toxicity against the Sf9 insect cell line and P. xylostella larvae than the wild type. We also found that infection of Sf9 and LD652Y-5d cell lines with P. taiwanensis induced apoptotic cell death. Further, natural oral infection by P. taiwanensis triggered expression of host programmed cell death-related genes JNK-2 and caspase-3.

Characterization of an insecticidal toxin and pathogenicity of Pseudomonas taiwanensis against insects.

The chilling requirement (CR) is the main factor controlling the peach floral bud break and subsequent reproductive growth. To date, several peach CR quantitative trait loci (QTLs) have been identified. To improve the accessibility and convenience of this genetic information for peach breeders, the aim of this study was to establish an easy-to-use genotype screening system using peach CR molecular markers as a toolkit for marker-assisted selection. Here, we integrated 22 CR-associated markers from three published QTLs and positioned them on the  physical map. Then, we built a PCR-based genotyping platform by using high-resolution melting (HRM) analysis with specific primers and trained this platform with 27 peach cultivars. Due to ambiguous variant calls from a commercial HRM software, we developed an R-based pipeline using principal component analysis (PCA) to accurately differentiate genotypes. Based on the PCA results, this toolkit was able to determine the genotypes at the CR-related single nucleotide polymorphisms (SNPs) in all tested peach cultivars. In this study, we showed that this HRM-PCA pipeline served as a low-cost, high-throughput, and non-gel genotyping solution. This system has great potential to accelerate CR-focused peach breeding.

A High Resolution Melting Analysis-Based Genotyping Toolkit for the Peach () Chilling Requirement.

The aim of this study is to simultaneously evaluate anti-oxidative and anti-inflammatory activities of the hop extracts by different solvents. Hop water extract (HWE) and hop ethanol extracts (HEEs) were prepared by extracting hop pellets with hot water at 90 °C and ethanol solutions (55%, 75%, and 95%), respectively. Bioactive compound such as α-acid, β-acid, total phenolic, and total flavonoid contents were determined. All the HEEs showed higher anti-oxidative activities than the HWEs. The HEEs showing the highest anti-oxidative activities are different in the experiments with different free radicals. For anti-inflammatory activities, both the HWE and HEEs decreased NO productions. HWE decreased TNF-α and IL-6 secretion but showed no effect on IL-1β, while HEEs decreased IL-1β and IL-6 secretion but increased TNF-α secretion. Except for TNF-α secretion, the HEEs showed higher anti-inflammatory activities than the HWE. Future work is to explore the possible mechanism to improve the ethanol extraction procedure.

Bioactive compounds with anti-oxidative and anti-inflammatory activities of hop extracts.

Interspecific hybridization is an effective strategy in  breeding programs for the introduction of new traits. Wild species within the  genus are valuable genetic resources for providing new horticulture traits and to improve environmental adaptations. However, reproductive barriers associated with fertilization and hybrid sterility must be overcome to produce fertile hybrid progenies. To approach the breeding objectives for  cut flower cultivars with long stem traits and adaptation to tropical/subtropical regions, a tropical species endemic to Taiwan,  Kudo, was used as a parent to cross with other long stem  species. Reciprocal crossing was effective in overcoming interspecific unilateral incompatibility in our crossed pairs. One superior hybrid, '103-1', produced capsules without seeds by selfing and backcrossing with pollens from either parent. Other than the seedless trait, failure of pollen releasing from anther, pollen aggregation and no pollen germination in '103-1' suggested its F sterility. Colchicine treatments on apical buds of '103-1' successfully overcame potential meiotic abnormalities by doubling ploidy. For the first time, fertile interspecific hybrids of  and  Engler were generated. The fertile hybrid has further produced progeny populations by crossing with  or  von Poelln, 'Ida'.

Restoring Fertility for Novel Interspecific Hybrids between  and  Using Colchicine Treatment.

Germination of mung beans increases the content of dietary fiber, vitamin C, antioxidants, and γ-aminobutyric acid (GABA). Atmospheric cold plasma is a recently developed technology that can rapidly modify the surface properties of an object. In this work, atmospheric cold plasma was utilized to promote higher moisture absorption of mung bean seeds and, thus, enhance the germination ratio and GABA level. The selected healthy seeds that were exposed to plasma generated at different ionizing powers.

Producing high quality mung bean sprout using atmospheric cold plasma treatment: better physical appearance and higher γ-aminobutyric acid (GABA) content.

Peanut allergy is recognized as a major food allergy that triggers severe and even fatal symptoms. Avoidance of peanuts in the diet is the main option for current safety management. Processing techniques reducing peanut allergenicity are required to develop other options. Cold plasma is currently considered as a novel non-thermal approach to alter protein structure and has the potential to alleviate immunoreactivity of protein allergen.

Fu-Chiun Hsu

Department of Horticulture and Landscape Architecture

National Taiwan University

Development of a Cabbage Protoplast System for Studying Hypoxia Tolerance in Brassica