Epigenomic insight of lingonberry and health-promoting traits during micropropagation.

Epigenetic variation plays a role in developmental gene regulation and responses to the environment. An efficient interaction of zeatin-induced cytosine methylation and secondary compounds has been displayed for the first time in tissue-culture shoots/plants of lingonberry (Vaccinium vitis-idaea L.) cultivar Erntedank in vitro (NC1, in a liquid medium; NC2, on a semi-solid medium), ex vitro (NC3, node culture-derived plants; LC1, leaf culture-derived plants) and its cutting-propagated (ED) plants. Through methylation-sensitive amplification polymorphism (MSAP) assay, we observed highest methylated sites in leaf regenerants (LC1) from all primer combinations (108 bands), along with the highest secondary metabolites. The four types of tissue culture-derived shoots/plants (NC1, NC2, NC3, LC1) showed higher methylation bands than cutting propagated donor plants (ED) that exhibited 79 bands of methylation, which is comparatively low. Our study showed more methylation in micropropagated shoots/plants than those derived from ED plants. On the contrary, we observed higher secondary metabolites in ED plants but comparatively less in micropropagated shoots (NC1, NC2) and plants (NC3, LC1).

Inheritance and mechanism of glyphosate resistance in annual bluegrass (Poa annua L.).

BACKGROUND: In initial screening, glyphosate was ineffective in controlling five Poa annua populations. These populations were tested for resistance, and studies undertaken to determine resistance mechanisms and inheritance pattern. RESULTS: Dose-response studies conducted at 16/12°C and 27/20°C on the five putative resistant populations showed low-level resistance (1.4- to 2.5-fold) to glyphosate. Shikimic acid accumulation in response to glyphosate confirmed differences among the populations, with greater shikimic acid accumulation in the susceptible population. The EPSPS gene copy number was 0.5- to 5.2-fold greater in one resistant population (HT) than in the susceptible (S) population, but not in the others. EPSPS gene expression was five- to tenfold higher in HT compared with the susceptible population. Target site mutations, differences in glyphosate absorption or translocation or altered expression of aldo-keto reductase (AKR) were not identified in any of the resistant populations. Crosses were successful between one resistant population and the susceptible population (P262-16♂ ✕ S♀) and inheritance of glyphosate resistance appears to be controlled by a single, nuclear dominant gene in this population. CONCLUSION: Our study identified EPSPS gene amplification in a South Australian glyphosate-resistant P. annua population (HT). This mechanism of resistance was not identified in the other four glyphosate-resistant populations, and other common mechanisms were excluded. Although the resistance mechanism in some P. annua populations remains unknown, inheritance studies with one population suggest the involvement of a single dominant gene. © 2021 Society of Chemical Industry.

Small scale production and characterization of xanthan gum synthesized by local isolates of Xanthomonas campestris.

Xanthan gum is a commercially important microbial exopolysaccharide (EPS) produced by Xanthomonas campestris. X. campestris is a plant pathogen causing various plant diseases such as black rot of crucifers, bacterial leaf blight and citrus canker disease resulting in crop damage. In this study, we isolated efficient local bacterial isolates which are capable to produce xanthan gum utilizing different sources of carbon (maltose, sucrose and glucose). Bacterial isolates from different plant leaves and fruits were identified as Xanthomonas campestris based on their morphological and biochemical characteristics. Among the 23 isolates, 70% were capable of producing gum. Taro plant, considered as new bacterial host, also have the capability to produce xanthan gum. Production conditions of xanthan gum and their relative viscosity by these bacterial isolates were optimized using basal medium containing commercial carbon and nitrogen sources and various temperature and rotation. Highest level of xanthan gum (18.286 g/l) with relative viscosity (7.2) was produced (Host, Citrus macroptera) at 28 degrees C, pH 7.0, 150 rpm using sucrose as a carbon source at orbital shaker. Whereas, in lab fermenter, same conditions gave best result (19.587 g/l gum) with 7.8 relative viscosity. Chilled alcohol (96%) was used to recover the xanthan gum. FTIR studies also carried out for further confirmation of compatibility by detecting the chemical groups.