Regulatory effect of pipecolic acid (Pip) on the antioxidant system activity of Mesembryanthemum crystallinum plants exposed to bacterial treatment

The presented study aims to elucidate the regulatory role of Pipecolic acid (Pip) in modulating the antioxidant system activity of Mesembryanthemum crystallinum plants exposed to Pseudomonas syringae infestation. M. crystallinum, known for its semi-halophytic nature, can transition its metabolism from C3 to CAM under salt stress conditions. The research encompasses the antioxidant system of the plants, covering both enzymatic and low molecular weight components. The findings indicate that Pip supplementation confers a beneficial effect on certain elements of the antioxidant system when the plants are subjected to stress induced by bacteria. Notably, during critical periods, particularly in the initial days post-bacterial treatment, M. crystallinum plants supplemented with Pip and exhibiting C3 metabolism display heightened total antioxidant capacity. This enhancement includes increased superoxide dismutase activity and elevated levels of glutathione and proline. However, in plants with salinity-induced CAM, where these parameters are naturally higher, the supplementation of Pip does not yield significant effects. These results validate the hypothesis that the regulatory influence of Pip on defence mechanisms against biotic stress is contingent upon the metabolic state of the plant. Furthermore, this regulatory effect is more pronounced in C3 plants of M. crystallinum than those undergoing CAM metabolism induced by salinity stress.

Pythium aphanidermatum as a Novel Oomycete Pathogen Causing Leak on Potato (Solanum tuberosum) in Korea

Potato (Solanum tuberosum L.) is one of the most important food crops in Korea. In July 2021 and 2022, dark black-rot symptoms with pink tinges were observed on field-grown potato tubers in Hongsung and Chuncheon, Korea, respectively. We obtained four isolates (HSv05 and HSv10 from Hongsung, and CCp03 and CCp05 from Chuncheon) from diseased tubers and identified these isolates as Pythium aphanidermatum by analyzing the sequences of internal transcribed spacer rDNA region and mitochondrial cytochrome c oxidase subunit II (COX2) mtDNA gene. Additionally, we compared the cultural and morphological characteristics of these four isolates with those of the reference isolate KACC 48066 of P. aphanidermatum and the literature. Further, we tested the pathogenicity of all these isolates against potato tubers. The cultural and morphological characteristics of the four test isolates were similar to those of the reference isolate and the literature; all four test isolates proved pathogenic to potato tubers. Therefore, we concluded that P. aphanidermatum is the causal agent of potato leak and this is the first report of the disease on potato in Korea.

Halophyte Common Ice Plants: A Future Solution to Arable Land Salinization

The problems associated with the salinization of soils and water bodies and the increasing competition for scarce freshwater resources are increasing. Current attempts to adapt to these conditions through sustainable agriculture involves searching for new highly salt-tolerant crops, and wild species that have potential as saline crops are particularly suitable. The common ice plant (Mesembryanthemum crystallinum L.) is an edible halophyte member of the Aizoaceae family, which switches from C3 photosynthesis to crassulacean acid metabolism (CAM) when exposed to salinity or water stress. The aim of this review was to examine the potential of using the ice plant in both the wild and as a crop, and to describe its ecology and morphology, environmental and agronomic requirements, and physiology. The antioxidant properties and mineral composition of the ice plant are also beneficial to human health and have been extensively examined.