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Hikosaka, K.

Publications and source records attributed to Hikosaka, K..

2 recordsLinked to original sources

A negative correlation between the rate coefficient of repair after photoinhibition of cold acclimated plants and the mean annual temperature of the habitats of Arabidopsis thaliana ecotypes

Both the activity of photosynthesis and the repair of damaged photosystems decline in cold environments, which may increase the extent of the damage of photosynthetic machinery by light, namely photoinhibition. We hypothesized that plants in colder habitats may possess greater tolerance to photoinhibition, especially in low temperature conditions. We measured the rate of photoinhibition, rate of photoinhibition repair and other thylakoid activities in cold environments using 298 Arabidopsis thaliana ecotypes and studied the relationships among the indicators of photoinhibition tolerance and climatic data of the habitat of each ecotype. The plants acclimated to cold conditions (12{degrees}C) for three days showed a negative correlation between the rate of photoinhibition repair at 5{degrees}C and the mean annual temperature of habitats, although we could not see this correlation with the control plants grown in 22{degrees}C. This result would indicate that the acclimation capacity of photoinhibition tolerance in cold conditions can affect the distribution of plants especially in colder regions.

plant biology↗

Suppressive effects of oroxylin A on intracellular proliferation of Toxoplasma gondii via host cell ERK phosphorylation inhibition

Toxoplasma gondii poses a significant threat to immunocompromised patients, resulting in high mortality rates. Considering the side effects of anti-Toxoplasma drugs, we focused on a potential candidate, oroxylin A (OA), a common component extracted from Astragalus membranaceus and Scutellaria baicalensis which suppressed the growth of T. gondii in vitro and in vivo. Our result demonstrated that OA suppressed T. gondii intracellular proliferation and downregulated phosphorylation of ERK1/2 of T. gondii-infected host cells very similar to the MEK1 specific inhibitor PD98059. Our in silico analysis showed that OA interacts sufficiently with the mammalian MEK1 region where established MEK1 inhibitors like PD98059 and trametinib bind. Moreover, OA improved the survival rate in T. gondii-infected mice. This study proposes that host MEK1 is a novel potential target for anti-Toxoplasma drugs with a new mechanism of action.

microbiology↗